SUCCESS!!!. 2011 Tacoma SR5 4x4. 131,000 miles. 2 mechanics and the guy at the parts store thought I was kidding (crazy). Been living with this for almost a year. Replaced master cylinder, new calipers and pads. No leaks anywhere............ever. Start the truck and the brake pedal goes to the floor, minimal brakes and barely drivable. Bled the brakes, same problem. Started the truck and the air bubbles in the tubing I used showed endless air bubbles in the left rear wheel cylinder. The rubbers were bone dry. Replaced the cylinder and am as good as new. Anyway, a HUGE Thank You from Vermont!
A follow up. A husband and wife were driving icy roads. Unfortunately, the brakes failed. There was nowhere to bail out. The left had a 50' ravine and to the right were boulders lining the road. In every state they would look at each other in desperation and she would scream with their pending demise. Every state except Vermont that is. The husband looked to his wife and said............................................ "Hold my beer and watch this".
Hi Joe: I had the same problem on a 2003 Ford Escape. It was the most irritating problem I had ever experienced with hydraulic brakes. It occurred during the Alberta winter, & at 80 years of age I was not going to lie on the ground fiddling with brakes ! I took the Escape (V6 4X4) to three shops & NONE of them could fix it. 4 Wheel hydraulic brakes are not rocket science, so living in the middle of nowher( my county is 5500 square miles & the pop. density is .6(yes, point 6 persons per square mile !). One of my farmer friends let me use his farm shop to work on the Escape. I built jumper tubings to eliminate the ABS Same problem. . The pedal was soft & it went damned nearly to the floor on a medium hard stop. I drew a schematic of the hydraulic system & sat & swilled coffee & thought about it. I had my friend pump the brakes up & hold all the pressure he could on the pedal. No sign of a leak anywhere, & we had exchanged master cylinders, with no difference with either cylinder. The master cylinder cups were holding, with no leak down. My friend said " What we are seeing is impossible ! " When I was working on radar in the Air Force, a knowledgeable specialist once remarked to me that when you see the impossible you are overlooking something After some thought. I disconnected the lines from the distribution block , one at a time & threaded a bolt into each hole. The right rear would never feel hard, & after a series of pumps the pedal went lower & lower. I bought TWO rear cylinders & changed them both & the problem was solved. Air can gain ingress to the cylinder but hydraulic fluid can't gain egress to the atmosphere if the cups are spongy. Great clip Joe, & I have subscribed. Cheers! Brian
Glad it worked out for you. Yes I also isolated and tested each line to find the problem. People comment here saying it’s impossible to not have it leaking fluid but that’s exactly what was happening.
Brian! I am dealing with a very similar problem, my friend! And your statement about hydraulic fluid not leaking into the atmosphere but air being able to be sucked into the brake system is spot on! I am experiencing a very similar problem where I can not achieve a firm brake pedal with the engine on. There has got to be a part that is sucking in air. I am down to the front calipers. Everything else has been replaced. And the front calipers look and work fine. They have got to be sucking in air. Got to be. Wish me luck and thanks! 😊
if this is true and solves my problem im going to lose it lol i even checked those rubber cups in both of my rear wheels they looked a bit charred but no signs of leakage anywhere
This is the first and ununique video on the internet tha talks about my problem,, just save me 300 dollars that this mechanic shop wanted to charge to fix my problem,, thank you so much ,, you were describing my problem stap by stap,, keep up the good work educating people like us,,! Good blass you,,,
THE FIRST SIGN OF HOPE! after watching my boss & his workers confused as hell, working on his ute non stop for 3 days straight! This explains the mystery. THANK YOU for the Info bro.
1993 Isuzu Trooper. This is exactly my issue. Brake pedal goes almost to the floor before firmly engaging. Had master cylinder replaced twice (one leaked), had brake booster replaced twice (one aftermarket leaked on arrival). The mechanic said he did not know what the problem was, so after $1000 limped home with the same problem. After viewing your video, it appears that I might have the air in the wheel cylinder problem. I get in the car and the brake pedal feels normal, with only slightly goes down. Turn on the engine and immediately the pedal goes almost to the floor before engaging. Also, while driving, I will pump the brakes a little before stopping, and I hear a hissing sound. I need a better brake mechanic. Thanks for the video. Thumbs up!
Hello. I know its been two years since you post your comment. I'm having the same problem with yours on my 1997 Isuzu Rodeo. Did you get your brakes fixed? What did you do? I replace my master brake cylinder and brake booster but still having the same problem as yours.
@@etc6272 After going through the aftermarket repelacements twice for the master cylinder and the brake booster, and having the brake system bled twice (there was never any air in the system and the wheel cylinders were not leaking), The last "new" (but not OEM") brake booster seemed to engage the brakes a little better than before, but not like it should be. The brake pedal still goes way down before engaging, but it does work. I have even done some hard stops, and no problems. It is just an uncomfortable feeling having the pedal go down so far before engaging. The last brake shop person said that the brakes were the best that he could do and that I just needed to accept the "new normal" braking situation. The brakelight on the dash never came on. I did find one video where an old mechanic addressed the problem: the after market brake boosters are supposed to work the same as the OEM part, but in reality, the little rod that goes from the booster to engage the master cylinder is often not the same length and needs a special adjustmeent. This makes sense, but most repair people are either unaware of this or do not want to take the time to make this adjustment. So, I accepted the "new normal" but always go through a mental drill for what to do if the brakes fail. I hope this helps. But now, I am have dash warning for the antilock brake system. Looking for parts and so far none fit. Good luck to you.
You can also isolate the front from the back by using vice grips with rubber hose over the teeth and clamp the rubber line in the rear and at each corner till you find the problem. That's how I found my front caliper was bound up and the peddle was going to the floor but it solved it once I freed up the caliper. Hope this helps others.
Follow up on my 98 Dodgeram 1500: Last thing I did was replace both rear brakes including wheel cylinders. One wheel cylinder had a little fluid drip out when I removed the rod that pushes the brakes against the drum. Although there was no fluid visible from the backside of the wheel plate and bleeder area, I am convinced it was the culprit just as Joe Stoe outlines here in this vid. Kudos to Joe! In the process of learning how to replace my own brakes front and rear, I not only got new brakes but learned a very good lesson on what to look for in the future before replacing the entire system. Thanks again Joe!
I was having the same exact symptoms with no brakes while engine on. It ended up being the brake caliper guide pins. They were packed with greased up dirt. Would allow the clipper to slide freely. Cleaned up with fresh grease and got my brakes back.
Way back, I had a VERY SCARY incident in my '69 Mustang. I had some brake service done, and for the day I picked it up, and my drive to college, everything was fine. The way home turned into a nightmare - coming up to a stop light on the highway (red), I stepped on the brake pedal - right to the floor with no resistance! Coming up fast on other stopped cars, I slammed it down as hard as I could several times and STOOD on it for the last few feet. Stopped in time. I continued slowly ahead, giving myself a lot of room for stopping, and went directly to the garage that had done the work (only about 6 blocks away). I could barely get the story out as I was shaking so much, and they fixed the issue. Never went back there for service.
If not winter, if this happens slowly pull up on e brake, I also suggest dropping gears. My cavalier shifter has reverse, neutral, drive, 3,2,1. My brakes went while I was in town and hobbled home using e brake and dropping it to 3,2,1 to slow down.
Always lower gears to slow the car down, also open your door fully, hold door open the air resistance will slow it down, last but not least play a good song on the radio really loud to take off the edge...........
Just happened to me...thus morning. I Thank God that traffic was light. I for a moment had to look at what tree to hit. Eventually after slowing down into a up hill. I was able to stop....Lesson is, periodically do a pre trip on your Veh!!!
Strange! The only time I encountered anything like that the problem was a bad bleed valve. The guy insisted the bleed valve was OK but changed it at my insistence and it solved the problem. Essentially, it was the same as what you describe: closing the valve stopped the fluid but it wasn't making a good seal and instead of drawing fluid into the piston on the pedal return, it was drawing air through the bleed valve.
Exact same problem on my 1991 F150. Original rear pistons, no leaks at all. But when I slid the boots off, 30 years of rust and brake fluid crud came out. Replaced both pistons and the petal got much stiffer. Having same problem with my 2000 4Runner and good to hear some validation to my theory.
Thanks for sharing. Your delivery of the subject is concise and informative. I have learned the hard way that air infiltration is not always something you can physically see with our light - gathering sensory organs / eyeballs. These microscopic gaps in brake hardware go undetected by our human brain.
I had that problem, I kept driving the pick up like that , only one rear wheel had brake functioning , Until now that I hear your comment ,and I will fix it soon. Thank you.
Sir, you are a Great American! My Son and I have been trying to figure out these exact symptoms on an 08 Chevy Suburban. Your video has been enormously helpful. Thank You.
Very much appreciate you taking the time to make this video. That issue of how air could get into a brake system when it wasn't opened is now answered. Thanks
I think Joe answered this question with him replacing the left rear brake cylinder. I can see how the cylinder was acting like a one way valve allowing air to enter the when the pedal was let up, but when pushing the pedal down the cylinder closed well enough to disallow fluid to leak out even under high pressure.
Hello Joe. I had this problem with a VW camper and a Renault Master motorhome.search the net but like you say, no answers. I fitted new master cylinder,new booster,bled the brakes to death but couldn’t solve the problem.Took it to a brake specialist who couldn’t solve the problem. Found your video so I’m going to follow your advise. Thank, Rob, England.
Very informative and good video. I put the vehicle up on Jack stands and had a friend apply the brakes then I went and rotated the hubs and found the right rear brake cylinder was defective. Replaced the wheel cylinder and got it working. Thanks
I had exactly the same problem with a Mitsubishi L200. When no brake fluid leaks out this can be very misleading and can make diagnosing the problem much more difficult. These pistons appear to be able to operate like a one way valve.
So there might be an oddball check ball in those. It's to keep fluid pressure from going all the way back to the mc, so that the drum pads stay closer to the drum. If the check ball is not working, the fluid flows back, and thus more fluid is needed the next time to actuate the rear brake.
I had a quite similar problem, long pedal travel and ABS working on the road, car passed MOT, I suspected master cylinder etc, but I bought a preloved ABS block and bingo.!
I had stuck piston then done the bleeding after the fix did it few times but just felt soft still then did it with the engine running went around twice start the back then front and that made them work better
I have the same issue on a 2003 Ford Taurus. I have replaced everything with new parts and even deleted the ABS. I have pressure bled the brakes numerous times to no avail . My brakes are very spongy and go to the floor slowly when I crank the engine. This car has the bubble flare fittings , and you can't purchase a cap to fit the end of the metal lines, so I sawed the metal ends off the rubber hoses , since I had replace them with new ones. I purchased two solid plugs that were 1/8 27 TPI threads. I already had a 1/8 27 tap. This is a grease jerk tap. I drilled the brass end where I sawed the hose off with a 21/64 drill bit and tapped it for my plugs. When tapping , be sure and leave 6 or 7 threads exposed or it will be to loose since it is a tappered tap. I had to make these since I needed the female bubble flare ends to cap the lines. Hope this helps someone to be able to isolate each wheel.
Also sometimes you can tighten up the bleeder this video helps you but if the bleeder doesn't seal properly it can suck in air I have had it happen to me a couple of times in my lifetime you tighten up the bleeder screw but the bleeder screw is not sealing correctly I put my car on the concrete driveway and the next morning I had a small puddle brake fluid on the driveway it was a new wheel cylinder the bleeder screw was defective you could also have a problem if you don't tighten up the bleeder screw tighten up especially on an old wheel cylinder when you are bleeding the brakes
Yes I agree a bad bleeder will cause a problem. I put a little grease around the bleeder when I was isolating each part of the system to find the air leak.
I gave my son my 08 Silverado and about a month ago the pedal got mushy. After he snapped 2 bolts on the front wheel bearing drifting around in the snow, I replaced the entire front brakes. A week ago he tells me he has to keep adding brake fluid. Well it's winter and with the snow I couldn't find a leak. So I put a new master cylinder in. STILL a mushy pedal. Pump it twice and they are as firm as can be. Only thing I can think of is a bad wheel cylinder and the adjuster not working. I HATE DRUM BRAKES!!!!
I'm having the same problem with a 68 charger .I've replaced everything new ,booster master,all lines, front disc brakes & yes recently replaced the rear drum brakes including the wheel cylinders & still goes to floor when running. Although today I noticed that if I try pumping a few inches from the floor it starts to build pressure. But when I let off the pedal & go to pump again,it's back to the floor. I'm glad you got lucky & fixed yours. This is driving me crazy.
Did you happen to see any brake fluud on the backside wheel hub assembly? Mine is wet there, so maybe that's it. I will try that before replacing the booster. Many thanks:
Very good, always check the basics. I work at a shop and we had the same problem with a corvette it would pull air in through a bad piston seal in the rear .
Bought my son his first truck, a 2007 tacoma. Have bled and bled with power bleeder. Super hard pedal. As soon as I turn truck on, pedal goes to the floor. Been working for days on it. No leaks at wheel cylinders in rear but it's getting air in somewhere. Nobody but you talked about it.
Well thank you very much I really appreciate you took your time to explain that problem which is my brother's problems too, I saved your video and I'm going to send it to him, it seems to me like he has the same kind of problem with his 1995 Chevy Truck, he has good brakes with the engine off and bad breaks with the on, Thanks man it's like you said it on your Tutorial that no one took the time to explain what you explained, appreciate it big time because it's kind of frustrated with it😮
Thank you I have the same problem on a 98 gmc 1500. Replaced the master cylinder same problem checked all wheel cylinders just as you did same problem air in left rear. Petal still goes to floor will change wheel cylinder and see if that fixes it. Glad I found your video.
Hello everyone, let me tell you the problem, when you have done everything under the sun to try to correct spongy brake pedal, the problem is the( Combinations Valve) it is designed when there is low pressure to the rear or to the front of the brake system, proportioning valve will cut off pressure to the part being bleed.!. It thinks there is a leak.!.. It is a safety measure in the design to combination Valve where you will not lose all breaks if a leak occurs.!. There is a little tool, that you can get on line, ( that's screws down in the brake light indicator ON the Combination Valve), to hold it in place .!... while you bleed the brakes, this will allow equal pressure to all wheels while bleed, when done bleeding reinstall brake light indicator combination valve.!. Try it friends...
I have the same problem with w123 230e auto shift. With the engine off, the brake pedal is stiff. As soon as engine runs and brakes are pressed, the pedal sinks with a slight increase in revs until the bottom of the pedal's stroke. The scenario repeats and brakes must be pumped to stop the car. Very dangerous indeed. This video helps a lot in eliminating minors first. Grateful as ever!
I have the exact same problem in a 94 silverado. Been down all the same avenues. Master cyl, brakes hoses, new calipers. Bled bled and bled and until I watched this video, I didn't think much of all the air I was getting out of the right rear wheel cyl. I thought that was just air still purging from the master cyl swap. I will try a new wheel cyl and def update the results in a couple days. Thank you. Pray this gets it . I'm out of ideas. UPDATE: I teplaced both rear wheel cylinders and it did not help. After more research, ive learned that the abs dump valve may have trapped air that will not bleed and an abs delete will be happening. I hope that works.
@@joestoe1610 Update to the update. One of the new wheel cyls was sucking air. Not leaking, just sucking air and wouldn't bleed. Had to exchange for another one and that fixed the problem. Although I did delete the abs . Looks cleaner under the hood and don't have to worry about that being an issue in the future.
Great video. I am having a similar issue. Pedal is hard. Does not sink. Start engine. Pedal sink... But I am not sure I am with you on the diagnosis (in my case), as I don't see how air can enter a cylinder while there is pressure on the pedal. (But when you let go of the pedal, then yes!). My brake system seem to can take my foot pressure, but not foot pressure + vacuum assist?? If I am not losing brake fluid the master cylinder must leak internally.
Curious if you solved your problem, I’m experiencing something similar- I can build pressure after a few pumps, whether with the engine on and driving or engine off. Yours sounds like brake booster from what I’ve found-
Thank You So Much ... !!! Thank You for All Your Homework ... !! No One has Been Able to Tell Me Ither ... !! But I've Just Learned A Great Pointer from You ... !! Thanks Again ... !!
I am dealing with this issue in 05 Camry. Flushed and bleed the entire system, tested master cylinder on bench and on the car by choking the ports and its all good. Changed hoses, calipers are serviced, nothing is stuck. There is no air in the system but still the pedal goes to the floor. After I drive the car for some time the brake rotors doesn't get hot as they should after some driving. This tells me that not enough pressure is going to the brakes, but loosing somewhere. But where? there is no leak, brake fluid stays at same level in the reservoir. Only thing I have not touched is the ABS module. ABS works though as I have recently tested on a slippery road. One interesting thing is that if I pinch any of the front hoses, the pedal does not sink. Pinching rear hoses doesn't improve the sinking.
@@barbmiracle I replaced the hoses, but the originals were fine too. In the end it was rear drum brakes wrong installation. When brakes were applied, the drum brakes had extra expansion due to wrong installation which caused the brake pedal to sink.
I have a 96 S10, I just can't get a normal brake pedal travel. I replaced the master cylinder, power brake booster, Rear wheel cylinders, rebuilt the front Disc calipers, New Disc pads, new brake shoes, Disc Rotors, Brake Drums, and all new brake hardware front and rear. I replace all these parts because they needed to be replaced. But when it came time to bleed the system. I just can't get a normal Pedal. When the engine is off. The brake pedal is hard, but when the engine is on, the pedal is probably a good 1" to 1-1/2" from the floor. Get this. I took my truck to the local Chevy dealer, and they told me this normal. The brake pedal was normal before I started this job. I pressure bled, and buddy bled the system before I took it to Chevy. The next step I'll try, is to isolate the master cylinder, to see the what pedal does without the whole brake system. All suggestions are welcomed. Thank you
Sounds a lot like all the stuff I just replaced on my S10. It is possible that you have a bad part even though it’s new. Try bleeding the brakes with the engine running, that’s what worked for me and how I found the bad wheel cylinder. Or there could be just a little more air stuck somewhere that bleeding with the engine running and making use of the brake booster will get it out. Isolating each part in the system is also a good idea to try. Forget the dealer, they don’t know about the older vehicles. If you have to take it somewhere, find a good local shop that works on older vehicles.
I gotta look at my brothers 99 Silverado this morning. Similar issue. It does stop, but that pedal is soft. I'm assuming somewhere around the wheel cylinder or a rusty brake line
Your great video led me to isolate the four corners of my car. I discover that the new calibres I had installed were boxed incorrectly and I had put them on the wrong sides with the bleeder valve faced down. Once I swapped them and bled them the brake pedal firmed right up. Thanks
Thank you so much for this post! I am also fighting the same issue on my 2001 s10 [4.3 v6] (we converted it to front/rear disc brakes) >yes we installed 3 new master cylinders >yes we installed new brake booster >yes all lines are new , no leakes (Yes i have a new proportion valve and the locking tool to keep the piston in place) We heard engine idle changes while trying to compress the brakes, could the engine vacuum leake be another cause for our issue? I just snapped and brke my pcv valve while trying to remove it. Tomorrow im going to install a new one. I also plam on installing another set of beans calipers in the rear. I plan on adding grease to the bleeder nipple to minimize air entrance issues. Does this sound remotly accurate? Or am i wasting more time and money? I figured this is a good approach because everything is custom at this point. If you want photos i can email you. Any help would be greatly appreciated. (I'm a welder/fabricator from Cleveland Ohio)
Thank you Joe I'll be sure to check those. I Replaced master cylinder and rebuilt front calipers. pedal still go to floor slowly brake check valve ok and booster. 😡 Focus zx3 01'
THANKS Joe, for sharing! It's one of those problems that is good to know, especially if you HAVE it. It's surprising that even experienced mechanics would not know how to find the underlying cause.
i finally found the answer. having same problem with a honda civic 1987 si and crx i change the booster and master cilinder and when i started the engine pedal goes to the floor pain in the butt. but i keep tracking this issue until i fix it doing that. you won't see any leaks at all. but that is the problem.
Could this happen to brake calipers as well, or just "wheel cylinders" that are found on drum brakes, I wonder. I also don't get why the brakes don't go the floor with the car off. It should still be leaking, I would think.
Place clamps on three of the four flexible brake hoses, and then pump the brakes, which will engage only the brake that is not clamped. If the pedal force is good, then you found one good brake. Continue with the other brakes by moving the three clamps to isolate a different brake and repeat until you identify the faulty brake. Also, it's best to clamp the flex hose at the end that is furthest from the caliper, as the flex hose itself might have the leak or simply be weak.
Do you do this with car running or not? I have caliper in all 4 corners. Would this still apply? Is the faulty one going to produce a soft/ mushy pedal then? And if so, replace caliper? Thanks
I had a right near parking break cable that was crimped somehow. It caused that caliper to get hot and start leaking. My break fluid level got to the point where it gave me a warning. Added fluid, and the breaks still functioned normally. Replaced that right rear caliper and started having this exact problem. Now I am wondering if it is the new caliper that is causing it. I guess I will try bleeding it again in a few days to see if I get more air out of it.
Same problem with my 2004 Saturn ion. But I’ve replaced the wheel cylinders and the calipers and the master cylinder. I eventually got a hard pedal but when starting the car it goes down. No leaks around the ABS module. I’m suspecting the booster. Also the engine rpm drops when holding the pedal down. I’ve heard that can be caused by a faulty booster
Well you almost had my problem solved, the one I'm working on I did the same routine that you did except this one is 03 zr2 . Replaced the booster twice, master cylinder twice went through 2 gallon brake fluid still no brake pedal when motor is running.
I bought my 2006 Cevy Malibu FSE used and it drives like a dream! I've had it for 2 years now and I haven't changed the brakes/brake pads/etc yet not had any major issues. Since I'm not loosing brake fluid, but the pedal is going down to the floor & It has never done that before- Does that mean it's time to change the brakes/brake pads/rotors etc....?? Someone please help! Thanks! 😃
Check the fluid level in your reservoir. If it’s a little low that’s a sign your brake pads are worn (if there are no leaks) then check your brakes and top off the reservoir. If it’s really low you have a leak somewhere.
I don't have wheel cylinders, but have the exact issue. Firm pedal when the engine isn't running, soft and to the floor/mushy when the engine is on. I guess I should try the Master Cylinder - 2003 Jeep Grand Cherokee., 4.0L
Working on the same truck with the same symptom, except not getting any air from the bleeders. Gonna see if an ODB1 scan tool has a procedure for bleeding th ABS assembly.
I ran into a similar issue on a 97 Yukon 4WD but the wheel cylinders were new. Brand new wheel cylinders on both sides and new drums and the pedal is rock soild until you turn the engine on. I bled everything you can possibly bleed over and over and over and ended up having to relinquish the job.
@@joestoe1610 The ABS had air stuck in it. Required a GM Tech 2 scanner to bleed the air since my Autel Maxisys doesn't have that function on the pre-2001 GM vehicles for some reason.
Hi, I installed a new JEGS brake booster and master cylinder in my 1977 Impala, but I have faced a problem. The brake performs well except sometimes when I push the brake, I lose it and feel the pedal sinking. Why does this happen?
I just bought this 2004 Suburban and I noticed the brake/ABS plug underneath the front passenger seat was unplugged. Soon as I plugged it up the 2 front brakes passenger /driver started dragging. I wonder if the previous owner unplugged the plug for that reason. To release the brakes I opened up the bleeder screw. And when I changed the brakes both passenger/driver side brakes was to the metal. Can having the ABS plugged up cause the brakes to drag? Leaving it unplugged will it help stop the dragging? BOTH SIDES ARE STICKING AT THE SAME TIME.
Replaced master cyl, booster, passenger side caliper (leaking) on a 98 Dodge ram 1500 (new caliper bleeder is up ) .....before doing this no warning indicators....bled breaks twice got a firm pedal engine off. Engine on, same problem at first... pedal all way to floor. Pumped a few times got a firm pedal with engine on after a minute. Put in reverse to back out of driveway and pedal goes to floor...no brakes. Drove down a less traveled road, stopped ok at a turnoff. turned around and no pedal again ..no brake! Drove back 1/2 mile to my driveway....stopped ok at intersection before turning off to my drive way, made a right turn into drive way and pedal again to floor...no brakes. Almost hit garage door, stopped by BBQ pit. Bled system again engine off , good pedal. Tried same drive test again same results except used E brake to save BBQ pit this time.:) Now getting ABS and Brake light warning. Master cyl full, no leaks apparent. Last brake job was 10,000 miles back.....shoes all good....little wear. Mike Bled brakes again today 3rd time , little to no air bubbles noted. Solid pedal until put in reverse to back up and then go forward I lose the pedal again. About ready to put new rear wheel cylinders in at this point , they aren't expensive...also a new drivers side front wheel caliper just to eliminate that possibility. ABS and Brake light still comes on after clearing with my scanner device. Beginning to suspect a bad ABS module and or pump.
Had same issue with my Son's 07 Silverado & after replacing almost all brake parts, bleeding, bleeding , & replacing rear brake wheel seals ECT. pedal goes close to floor with engine running. I'll give a try with motor running & go from there. Thanks for posting this .
The vacuum assist brake booster behind the master cylinder will almost pull it down to the floor when the engine is running if there is any air in the lines that will compress. When you press the brake pedal , it opens the check valve and allows the vacuum assist.
I have the same exact issue with my Civic. I just changed the driver side rotor, caliper, and pads and my pedal sinks to the floor with the engine on and before I did anything my pedal was perfect. Maybe it's air that's causing it but I dont know. I can't drive anywhere in the condition it's in. I should have left everything alone and took my car to the shop to my brakes done. I'm not happy right now, I am not a mechanic but I've brake jobs before.
It’s most likely air if you replaced the caliper. Make sure you have the correct caliper on that side as they are interchangeable and if wrong you’ll never get the air out. Also bleed the whole system not just that wheel. Yes It’s a pain
I just did my rear brakes, all new parts, bags of parts and new shoes. Bled a half gallon of brake fluid out. Bench bled my master again. Pedal to the floor. But I still haven't bled to the front wheels. I saw one guy who plugged the master ports to see if it was good. My last step will be to take out the ABS. Looks very hard since I will have to learn how to bend brake lines.
That's a great video and it also answers a question of mine at the same time. I'm going to be replacing my calipers on my 2001 Dodge ram 1500 pick up. I noticed one of the pistons on the passenger side was crumbling and I knew it was going to be a problem later on. I spotted this because I had just changed my brake pads in the front. After changing the pads, I started up my truck, and pump the brakes to get a solid pedal back because I think that's the best way to get a pedal with the assistance of the booster. I just don't understand how people can complete the brakes and not have the engine running. Doesn't the pedal give you a tail sign that it's OK? It just doesn't seem right to me.
I have the same problem exactly on my 93 Typhoon. After replacing the same components that you did (except booster) I was about replace the booster. I read how much of a pain it is to replace on these vehicles, so I scanned youtube for an easier way to replace it. I came upon your video and decided to try your fix... I will let you know if it works when I am done.
I dont understand how the wheel cylinder can "suck" air in, and yet not leak any fluid.....but in your case, the problem defied physics. I am going thru the same issues.....pedal goes to the floor when starting engine. I have replaced the Master B. C., the Booster, and bleed the brakes many times. No leaks anywhere. I also deleted the ABS system. On my Mit. Montero, there was a "return" line coming from the rear brakes to the ABS box. Should I have deleted this return line? I just routed the return rear line to a junction with the main MBC push line which went into a junction that fed brake fluid to all the brakes. Is this "Do-Loop" maybe my problem? Thanks
I having the same issue with my kids 05 Altima. We replaced all 4 calipers and replaced the master cylinder 2 times. Bleeds fine, pedal gets hard when cars off but when I start it, I got a soft pedal...
I am having a similar problem with my 1998 Chevy Silverado when I first got the truck the first thing I did fix on it was the brake line and the brake lines that connect onto the rear brake drum cylinders, days go by and I get to change the springs and brand new rear brake cylinders on both rear wheels, went to put the front and installed both driver and passenger brake hoses. I later on bled the brakes and passenger rear had a good amount of air, moved on to the driver rear and it was the one with the most air but we got it good, went to the front two and they bled pretty good, after that brake would get more sturdy but if pressed past the pressure point it just sinks and it gets stuck. I though there was not pressure building up so i put in a brand new brake master cylinder and it is still sinking. I haven't changed the brake booster or the abs. Would it be one of them?
im having the same problem on my 2010 subaru forester and i don't have rear wheel cylinders . when sitting at a red light with my foot pressing on the brake pedal the pedal goes slowly to the floor... i replaced the master cylinder, benched bled the new one... bled the complete brake calipers...no leaks anywhere in the system but the brakes slowly goes to the floor... also no brake fluid in the booster... booster works good..
I don't recommend using grease on the bleeders. The fluid will dilute it very quickly. I clean the threads and wrap them a few times in teflon tape. Won't suck air in when you bleed and also won't rust sieze on you next time they need to servicing years down the line.
I've just seen ur video .we'll I changed wheel cylinders .ever since I did I had thos issue brand new but the cheap cylinder changed all the brake lines master cylinder etc .ended up changing rear cylinder again . for decent quality ...hopefully when I connect everything g back up this issue will be fixed .thanks for your advice .
For my one all brake accessories such as master pump with booster, front caliper, rear cylinders all are brand new and still have the problem. Any ideas for that?
Oh yes this helped. I pushed out the piston on both brake cylinders recently while changing my drum brakes. I have the same issue as you. I probably need to replace both cylinders.
THANK YOU - my Saturn2006 VUE just lost braking - went into a soft brake mode so .. I had exactly the same problem with drive rear cylinder ay thank for your efforts !
My cylinder was leaking the rubber deal slid off to one side i noticed rust and a drip on inside wheel and drum rusty. Knew i had problem still frustrating though.
Hi Joe Stoe, Thanks for sharing your experience with the brake pedal issue when the engine is started. It's valuable insights like yours that help us troubleshoot and solve problems. My parents have a 2013 Multivan, and this problem sounds familiar. I'll definitely be checking your suggestion on my van as soon as I get home today. Appreciate the heads up and any additional tips you might have! Best regards,
I had just finished putting back brakes on my daughters Jetta. I replaced the wheel cylinders on both rear brakes, the passenger side had started to leak a few days ago. Anyway, I replaced them and put new shoes on. I still have a very soft brake when the car is turned on. I did not have the car running through when I bled the lines. I did all four wheels and got very little air. So, your suggesting I should have the car running when I bled the lines?
George the problem is in the combination valve, it thinks there is low pressure one side of the system, when you are bleeding it, and cuts the pressure from the master cylinder to it, this is a safety design in the combination.!. To where all brakes will not be lost if it is a loss in pressure, there is a special tool that screws into the combination valve, to hold it in place while bleeding, it will equalize all pressure to the wheels. You can get the little tool online for around $8.00 Bucks give it a try ...
Hi, my break down to floor when car is running. Break works ok but just soft and going to floor. I changed the master cylinder and booster but still the same. Machanic too does not know much. What will be possible solution?
Combination valve , safety mechanism is activating when you are bleeding brakes.!!!... Remove they light indicator combination valve, They make a little tool that screws into combination valve to hold it in place, while you bleed the brakes, ( here is an example on how they combination valve work's , a loss of pressure are low pressure the combination valve thinks there is a leak, they spring mechanism inside the valve will shut off pressure to front or the rear , to help from total loss of Brakes.
Wonder if that's my problem with my calipers, replaced master cylender after meticulously bench bleeding it. Left rear caliper keeps getting air with no fluid leak
Joe Stoe! I like that name sir!I have an issue .maybe you can help me or point me in the right direction!I have a 2008 chevy express 2500.I get a, or have a soft brake pedal.So I inspected everything, calipers, master cylinder, hoses and lines, etc.... No leaks.So then I would bleed the brakes and I would have a hard brake ,stiff pedal for a few months, then the peda would get soft again.Bleeding helps but just for a few months.Oh, I get what sounds like the the abs system activating when you are sliding on snow or ice during routine driving.it only does it for a few seconds when the vehicle comes to a stop.Is this related to my soft pedal ? Help anyone. I did just replace my power steering reservoir cause it was leaking fluid through the rusty reservoir body.I'm pretty sure air got in the lines but I wouldn't think that would affect the brake/ hydro boost system / function? 🤔 🗣" Helllppppp!!!!""🥺
I don’t know but someone else might. I would check for an ABS code first and then bleed the ABS unit. Can they leak internally? You might have to take it to a shop for that.
@@joestoe1610 ok joe.I don't have any abs codes but I'll look into it.I bled the brakes last weekend and now I have good brakes, toe touch tight!!! I talked to the guy I take my cars to when I can't figure it out myself,and he said to see if the master cylinder is leaking internally sucking air somehow.🤷🏽♂️ . My mechanic buddy said its not the hydroboost because it would would create a hard pedal if it was malfunctioning.... I'll replace the master cylinder and see what happens. Thanks Joe Stoe!!!
I replaced some brake lines in my 2005 GMC Jimmy and had the same problem. The ABS had air in it so engine off I would push the pedal down with a stick, then loosen the abs line at the abs and let air out, then tighten, release pedal and press it again holding it in with the stick. Just like bleeding the brakes at the wheel. Lots of air came out and that was the problem.
I have this problem but don't think i have a brake cylinder. My rear rotors are drum + disk. 02 Jeep Grand Cherokee Laredo 4.7L V8 VIN-N Selec-Trac SOHC. My pedal goes almost to the floor before i get brakes and they work but are weak. No visible leaks at calipers or in wheels or at master cylinder. Pads look like they have at least over half pad left.. Maybe im leaking fluid from master cylinder into power brake booster but not sure. I do have missing brake fluid that went below min mark. It doesn’t leak fast, it was 5+ months before i had brake light on with low fluid in master cylinder reservoir. I just dumped what i had left of DOT3 but its only up to minimum. Ill order 5x 12oz bottles soon with a bleeder bottle kit so i can do it myself. One of thw brands Allstar has a one way chwck valve on bottle so you can't get air in brake lines. Let me know if you know what this is?
Same problem on a 98 Corolla the whell cylinders never leaked but sucked air bad . Finally checked them soon i touch the rubber boot they poured fluid .
SUCCESS!!!. 2011 Tacoma SR5 4x4. 131,000 miles. 2 mechanics and the guy at the parts store thought I was kidding (crazy). Been living with this for almost a year. Replaced master cylinder, new calipers and pads. No leaks anywhere............ever. Start the truck and the brake pedal goes to the floor, minimal brakes and barely drivable. Bled the brakes, same problem. Started the truck and the air bubbles in the tubing I used showed endless air bubbles in the left rear wheel cylinder. The rubbers were bone dry. Replaced the cylinder and am as good as new. Anyway, a HUGE Thank You from Vermont!
A follow up. A husband and wife were driving icy roads. Unfortunately, the brakes failed. There was nowhere to bail out. The left had a 50' ravine and to the right were boulders lining the road. In every state they would look at each other in desperation and she would scream with their pending demise. Every state except Vermont that is. The husband looked to his wife and said............................................ "Hold my beer and watch this".
I live in Vermont having same problem in my land cruiser 80's slam brake all the way to the floor to barely slow down. No leaking, full brake fluid
Hi Joe: I had the same problem on a 2003 Ford Escape. It was the most irritating problem I had ever experienced with hydraulic brakes. It occurred during the Alberta winter, & at 80 years of age I was not going to lie on the ground fiddling with brakes ! I took the Escape (V6 4X4) to three shops & NONE of them could fix it. 4 Wheel hydraulic brakes are not rocket science, so living in the middle of nowher( my county is 5500 square miles & the pop. density is .6(yes, point 6 persons per square mile !). One of my farmer friends let me use his farm shop to work on the Escape. I built jumper tubings to eliminate the ABS Same problem. . The pedal was soft & it went damned nearly to the floor on a medium hard stop. I drew a schematic of the hydraulic system & sat & swilled coffee & thought about it. I had my friend pump the brakes up & hold all the pressure he could on the pedal. No sign of a leak anywhere, & we had exchanged master cylinders, with no difference with either cylinder. The master cylinder cups were holding, with no leak down. My friend said " What we are seeing is impossible ! " When I was working on radar in the Air Force, a knowledgeable specialist once remarked to me that when you see the impossible you are overlooking something After some thought. I disconnected the lines from the distribution block , one at a time & threaded a bolt into each hole. The right rear would never feel hard, & after a series of pumps the pedal went lower & lower. I bought TWO rear cylinders & changed them both & the problem was solved.
Air can gain ingress to the cylinder but hydraulic fluid can't gain egress to the atmosphere if the cups are spongy.
Great clip Joe, & I have subscribed.
Cheers! Brian
Oh I like that Idea test each line for pressure that is out of the box thinking and I'm stealing the idea when I get a problem like that
Glad it worked out for you. Yes I also isolated and tested each line to find the problem. People comment here saying it’s impossible to not have it leaking fluid but that’s exactly what was happening.
Brian!
I am dealing with a very similar problem, my friend! And your statement about hydraulic fluid not leaking into the atmosphere but air being able to be sucked into the brake system is spot on! I am experiencing a very similar problem where I can not achieve a firm brake pedal with the engine on. There has got to be a part that is sucking in air. I am down to the front calipers. Everything else has been replaced. And the front calipers look and work fine. They have got to be sucking in air. Got to be. Wish me luck and thanks! 😊
What did u find out?@@jakebpau2396
if this is true and solves my problem im going to lose it lol i even checked those rubber cups in both of my rear wheels they looked a bit charred but no signs of leakage anywhere
This is the first and ununique video on the internet tha talks about my problem,, just save me 300 dollars that this mechanic shop wanted to charge to fix my problem,, thank you so much ,, you were describing my problem stap by stap,, keep up the good work educating people like us,,! Good blass you,,,
This video may have just saved what little bit of sanity I have left!!! I’m going to give this a shot. This has been a non stop problem. Thank you
Update?
Update?
I broke down and sold the damn thing to someone who wanted a project truck and bought a new car.
Bummer
@@jamespennington420. lolol
THE FIRST SIGN OF HOPE! after watching my boss & his workers confused as hell, working on his ute non stop for 3 days straight! This explains the mystery. THANK YOU for the Info bro.
1993 Isuzu Trooper. This is exactly my issue. Brake pedal goes almost to the floor before firmly engaging. Had master cylinder replaced twice (one leaked), had brake booster replaced twice (one aftermarket leaked on arrival). The mechanic said he did not know what the problem was, so after $1000 limped home with the same problem. After viewing your video, it appears that I might have the air in the wheel cylinder problem. I get in the car and the brake pedal feels normal, with only slightly goes down. Turn on the engine and immediately the pedal goes almost to the floor before engaging. Also, while driving, I will pump the brakes a little before stopping, and I hear a hissing sound. I need a better brake mechanic. Thanks for the video. Thumbs up!
Hello. I know its been two years since you post your comment. I'm having the same problem with yours on my 1997 Isuzu Rodeo. Did you get your brakes fixed? What did you do? I replace my master brake cylinder and brake booster but still having the same problem as yours.
@@etc6272 After going through the aftermarket repelacements twice for the master cylinder and the brake booster, and having the brake system bled twice (there was never any air in the system and the wheel cylinders were not leaking), The last "new" (but not OEM") brake booster seemed to engage the brakes a little better than before, but not like it should be. The brake pedal still goes way down before engaging, but it does work. I have even done some hard stops, and no problems. It is just an uncomfortable feeling having the pedal go down so far before engaging. The last brake shop person said that the brakes were the best that he could do and that I just needed to accept the "new normal" braking situation. The brakelight on the dash never came on. I did find one video where an old mechanic addressed the problem: the after market brake boosters are supposed to work the same as the OEM part, but in reality, the little rod that goes from the booster to engage the master cylinder is often not the same length and needs a special adjustmeent. This makes sense, but most repair people are either unaware of this or do not want to take the time to make this adjustment.
So, I accepted the "new normal" but always go through a mental drill for what to do if the brakes fail. I hope this helps. But now, I am have dash warning for the antilock brake system. Looking for parts and so far none fit. Good luck to you.
You can also isolate the front from the back by using vice grips with rubber hose over the teeth and clamp the rubber line in the rear and at each corner till you find the problem. That's how I found my front caliper was bound up and the peddle was going to the floor but it solved it once I freed up the caliper. Hope this helps others.
Yes That does work. I had to do that as well a few times!
I'm going to try that, thanks.
What teeth you talking about please help so I can do this test
@@slv_car_refinisher6864 the teeth on the vise grips need to be covered to not cut the lines
@@lyallfairburn1275 what rubber hose did you put on the teeth)
Follow up on my 98 Dodgeram 1500: Last thing I did was replace both rear brakes including wheel cylinders. One wheel cylinder had a little fluid drip out when I removed the rod that pushes the brakes against the drum. Although there was no fluid visible from the backside of the wheel plate and bleeder area, I am convinced it was the culprit just as Joe Stoe outlines here in this vid. Kudos to Joe! In the process of learning how to replace my own brakes front and rear, I not only got new brakes but learned a very good lesson on what to look for in the future before replacing the entire system. Thanks again Joe!
Thanks for the update! So often you only hear about the problem and not the solution. Glad it worked out!
I was having the same exact symptoms with no brakes while engine on. It ended up being the brake caliper guide pins. They were packed with greased up dirt. Would allow the clipper to slide freely. Cleaned up with fresh grease and got my brakes back.
Way back, I had a VERY SCARY incident in my '69 Mustang. I had some brake service done, and for the day I picked it up, and my drive to college, everything was fine. The way home turned into a nightmare - coming up to a stop light on the highway (red), I stepped on the brake pedal - right to the floor with no resistance! Coming up fast on other stopped cars, I slammed it down as hard as I could several times and STOOD on it for the last few feet. Stopped in time. I continued slowly ahead, giving myself a lot of room for stopping, and went directly to the garage that had done the work (only about 6 blocks away). I could barely get the story out as I was shaking so much, and they fixed the issue. Never went back there for service.
Wow! Glad it no one got hurt!
If not winter, if this happens slowly pull up on e brake, I also suggest dropping gears. My cavalier shifter has reverse, neutral, drive, 3,2,1. My brakes went while I was in town and hobbled home using e brake and dropping it to 3,2,1 to slow down.
Always lower gears to slow the car down, also open your door fully, hold door open the air resistance will slow it down, last but not least play a good song on the radio really loud to take off the edge...........
@@ironjohn5914 lmao 😂😂😂😂😂😂😂😂
Best advice ever!👍👍👍👍🕺🕺🕺
Just happened to me...thus morning. I Thank God that traffic was light. I for a moment had to look at what tree to hit. Eventually after slowing down into a up hill. I was able to stop....Lesson is, periodically do a pre trip on your Veh!!!
Strange! The only time I encountered anything like that the problem was a bad bleed valve. The guy insisted the bleed valve was OK but changed it at my insistence and it solved the problem. Essentially, it was the same as what you describe: closing the valve stopped the fluid but it wasn't making a good seal and instead of drawing fluid into the piston on the pedal return, it was drawing air through the bleed valve.
Exact same problem on my 1991 F150. Original rear pistons, no leaks at all. But when I slid the boots off, 30 years of rust and brake fluid crud came out. Replaced both pistons and the petal got much stiffer. Having same problem with my 2000 4Runner and good to hear some validation to my theory.
Thanks for sharing. Your delivery of the subject is concise and informative. I have learned the hard way that air infiltration is not always something you can physically see with our light - gathering sensory organs / eyeballs. These microscopic gaps in brake hardware go undetected by our human brain.
I had that problem, I kept driving the pick up like that , only one rear wheel had brake functioning , Until now that I hear your comment ,and I will fix it soon. Thank you.
😂 dam thats not funny but cmon pilgrim you should know dam better
Sir, you are a Great American! My Son and I have been trying to figure out these exact symptoms on an 08 Chevy Suburban. Your video has been enormously helpful. Thank You.
Very much appreciate you taking the time to make this video. That issue of how air could get into a brake system when it wasn't opened is now answered. Thanks
7th 9i😊uju9😊😊
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0
The problem I see here is if it can pull air why isn't there a sign of leaking fluid as it is under extreme hydraulic pressure?
I think Joe answered this question with him replacing the left rear brake cylinder. I can see how the cylinder was acting like a one way valve allowing air to enter the when the pedal was let up, but when pushing the pedal down the cylinder closed well enough to disallow fluid to leak out even under high pressure.
Omg as a woman with a 2007 Toyota Tundra. Wow may have saved me lots of money. Thank you ❤
Hello Joe. I had this problem with a VW camper and a Renault Master motorhome.search the net but like you say, no answers. I fitted new master cylinder,new booster,bled the brakes to death but couldn’t solve the problem.Took it to a brake specialist who couldn’t solve the problem.
Found your video so I’m going to follow your advise. Thank, Rob, England.
Good luck I hope it helps. I don’t know why there aren’t more videos solving the problem that a lot of people have.
Very informative and good video. I put the vehicle up on Jack stands and had a friend apply the brakes then I went and rotated the hubs and found the right rear brake cylinder was defective. Replaced the wheel cylinder and got it working. Thanks
Great!
I had exactly the same problem with a Mitsubishi L200. When no brake fluid leaks out this can be very misleading and can make diagnosing the problem much more difficult. These pistons appear to be able to operate like a one way valve.
So there might be an oddball check ball in those. It's to keep fluid pressure from going all the way back to the mc, so that the drum pads stay closer to the drum. If the check ball is not working, the fluid flows back, and thus more fluid is needed the next time to actuate the rear brake.
What manufacturer?
Is the check ball inside the wheel cylinder?
Merci Joe. Excellent pour les novices et tous les amateurs de mécanique automobile.
I had a quite similar problem, long pedal travel and ABS working on the road, car passed MOT, I suspected master cylinder etc, but I bought a preloved ABS block and bingo.!
So the used ABS unit solved your problem? Great!
Thank you for thinking enough of others to offer what you found. I will certainly give it a try.
I had stuck piston then done the bleeding after the fix did it few times but just felt soft still then did it with the engine running went around twice start the back then front and that made them work better
I have the same issue on a 2003 Ford Taurus. I have replaced everything with new parts and even deleted the ABS. I have pressure bled the brakes numerous times to no avail . My brakes are very spongy and go to the floor slowly when I crank the engine. This car has the bubble flare fittings , and you can't purchase a cap to fit the end of the metal lines, so I sawed the metal ends off the rubber hoses , since I had replace them with new ones. I purchased two solid plugs that were 1/8 27 TPI threads. I already had a 1/8 27 tap. This is a grease jerk tap. I drilled the brass end where I sawed the hose off with a 21/64 drill bit and tapped it for my plugs. When tapping , be sure and leave 6 or 7 threads exposed or it will be to loose since it is a tappered tap. I had to make these since I needed the female bubble flare ends to cap the lines. Hope this helps someone to be able to isolate each wheel.
Also sometimes you can tighten up the bleeder this video helps you but if the bleeder doesn't seal properly it can suck in air I have had it happen to me a couple of times in my lifetime you tighten up the bleeder screw but the bleeder screw is not sealing correctly I put my car on the concrete driveway and the next morning I had a small puddle brake fluid on the driveway it was a new wheel cylinder the bleeder screw was defective you could also have a problem if you don't tighten up the bleeder screw tighten up especially on an old wheel cylinder when you are bleeding the brakes
Yes I agree a bad bleeder will cause a problem. I put a little grease around the bleeder when I was isolating each part of the system to find the air leak.
The angle of taper is steeper in the after.market bleeders. They do not seat correctly !
God bless honest hard worker people who share his valuable experience with others ❤
I gave my son my 08 Silverado and about a month ago the pedal got mushy. After he snapped 2 bolts on the front wheel bearing drifting around in the snow, I replaced the entire front brakes. A week ago he tells me he has to keep adding brake fluid. Well it's winter and with the snow I couldn't find a leak. So I put a new master cylinder in. STILL a mushy pedal. Pump it twice and they are as firm as can be. Only thing I can think of is a bad wheel cylinder and the adjuster not working. I HATE DRUM BRAKES!!!!
I'm having the same problem with a 68 charger .I've replaced everything new ,booster master,all lines, front disc brakes & yes recently replaced the rear drum brakes including the wheel cylinders & still goes to floor when running. Although today I noticed that if I try pumping a few inches from the floor it starts to build pressure. But when I let off the pedal & go to pump again,it's back to the floor. I'm glad you got lucky & fixed yours. This is driving me crazy.
Wow that's crazy. Did you find the problem?
update?
Did you happen to see any brake fluud on the backside wheel hub assembly? Mine is wet there, so maybe that's it.
I will try that before replacing the booster. Many thanks:
Yes much easier than replacing the booster. It’s rarely the booster and you can look up tests for that
Very good, always check the basics. I work at a shop and we had the same problem with a corvette it would pull air in through a bad piston seal in the rear .
This video confirmed exactly my brake issue on my 1994 4Runner. Thank you!
Thanks! Having the same issue with my 2004 Xterra. No visible leaks, but a poor pedal. Nothing to lose swapping the wheel cylinders. Cheers.
Bought my son his first truck, a 2007 tacoma. Have bled and bled with power bleeder. Super hard pedal. As soon as I turn truck on, pedal goes to the floor. Been working for days on it. No leaks at wheel cylinders in rear but it's getting air in somewhere. Nobody but you talked about it.
Thanks Joe! My 01 Ram 1500 is a rust bucket and wheel cylinders are the cure for the problem
Well thank you very much I really appreciate you took your time to explain that problem which is my brother's problems too, I saved your video and I'm going to send it to him, it seems to me like he has the same kind of problem with his 1995 Chevy Truck, he has good brakes with the engine off and bad breaks with the on, Thanks man it's like you said it on your Tutorial that no one took the time to explain what you explained, appreciate it big time because it's kind of frustrated with it😮
Thank you I have the same problem on a 98 gmc 1500. Replaced the master cylinder same problem checked all wheel cylinders just as you did same problem air in left rear. Petal still goes to floor will change wheel cylinder and see if that fixes it. Glad I found your video.
Great, let me know if you get it solved!
Hello everyone, let me tell you the problem, when you have done everything under the sun to try to correct spongy brake pedal, the problem is the( Combinations Valve) it is designed when there is low pressure to the rear or to the front of the brake system, proportioning valve will cut off pressure to the part being bleed.!. It thinks there is a leak.!.. It is a safety measure in the design to combination Valve where you will not lose all breaks if a leak occurs.!. There is a little tool, that you can get on line, ( that's screws down in the brake light indicator ON the Combination Valve), to hold it in place .!... while you bleed the brakes, this will allow equal pressure to all wheels while bleed, when done bleeding reinstall brake light indicator combination valve.!. Try it friends...
This was not my problem this time but I’ve had it happen in the past and I used a small pick to move the valve back in place. Good tip
Can you explain where I can find this?
@@barbmiracleinside the proportioning valve, not all brake systems have them - they are to divert fluid to the rear and front at different rates
What year vehicles are you referring to? I have a 1997 dodge ram. Can you show a picture?
Seems like my pedal returns to the normal position but the brake lights are staying on. Why?
Thanks I'm having same problem but not seeing any leaks I'm going to try that before buying a master cylinder
I have the same problem with w123 230e auto shift. With the engine off, the brake pedal is stiff. As soon as engine runs and brakes are pressed, the pedal sinks with a slight increase in revs until the bottom of the pedal's stroke. The scenario repeats and brakes must be pumped to stop the car. Very dangerous indeed.
This video helps a lot in eliminating minors first. Grateful as ever!
I have the exact same problem in a 94 silverado. Been down all the same avenues.
Master cyl, brakes hoses, new calipers. Bled bled and bled and until I watched this video, I didn't think much of all the air I was getting out of the right rear wheel cyl. I thought that was just air still purging from the master cyl swap.
I will try a new wheel cyl and def update the results in a couple days. Thank you. Pray this gets it . I'm out of ideas.
UPDATE: I teplaced both rear wheel cylinders and it did not help. After more research, ive learned that the abs dump valve may have trapped air that will not bleed and an abs delete will be happening. I hope that works.
Yes, the ABS is often the culprit!
@@joestoe1610 Update to the update. One of the new wheel cyls was sucking air. Not leaking, just sucking air and wouldn't bleed. Had to exchange for another one and that fixed the problem. Although I did delete the abs . Looks cleaner under the hood and don't have to worry about that being an issue in the future.
Great video. I am having a similar issue. Pedal is hard. Does not sink. Start engine. Pedal sink... But I am not sure I am with you on the diagnosis (in my case), as I don't see how air can enter a cylinder while there is pressure on the pedal. (But when you let go of the pedal, then yes!). My brake system seem to can take my foot pressure, but not foot pressure + vacuum assist?? If I am not losing brake fluid the master cylinder must leak internally.
Curious if you solved your problem, I’m experiencing something similar- I can build pressure after a few pumps, whether with the engine on and driving or engine off. Yours sounds like brake booster from what I’ve found-
@@roberth9188 I just put in a brand new brake master cylinder... and it did not solve it.
Thank You So Much ... !!!
Thank You for All Your Homework ... !!
No One has Been Able to Tell Me Ither ... !!
But I've Just Learned A Great Pointer from You ... !!
Thanks Again ... !!
Thank you sir
I had the same problem and as soon as I seen your video it all became clear
You helped me fix my brakes
God bless
Glad it helped
Yeah, I remember changing those with my dad. I have this issue. And I am about to check those rear cylinders.
I am dealing with this issue in 05 Camry. Flushed and bleed the entire system, tested master cylinder on bench and on the car by choking the ports and its all good. Changed hoses, calipers are serviced, nothing is stuck. There is no air in the system but still the pedal goes to the floor. After I drive the car for some time the brake rotors doesn't get hot as they should after some driving. This tells me that not enough pressure is going to the brakes, but loosing somewhere. But where? there is no leak, brake fluid stays at same level in the reservoir. Only thing I have not touched is the ABS module. ABS works though as I have recently tested on a slippery road.
One interesting thing is that if I pinch any of the front hoses, the pedal does not sink. Pinching rear hoses doesn't improve the sinking.
I wonder if the hoses need replacing?
@@barbmiracle I replaced the hoses, but the originals were fine too. In the end it was rear drum brakes wrong installation. When brakes were applied, the drum brakes had extra expansion due to wrong installation which caused the brake pedal to sink.
@@someone1089 I was having issues getting a good bleed on a rear brake job. Turns out the calipers were on the wrong sides... lol oops.
good info to keep in mind just in case I ever run across that problem.
I have a 96 S10, I just can't get a normal brake pedal travel. I replaced the master cylinder, power brake booster, Rear wheel cylinders, rebuilt the front Disc calipers, New Disc pads, new brake shoes, Disc Rotors, Brake Drums, and all new brake hardware front and rear. I replace all these parts because they needed to be replaced. But when it came time to bleed the system. I just can't get a normal Pedal. When the engine is off. The brake pedal is hard, but when the engine is on, the pedal is probably a good 1" to 1-1/2" from the floor. Get this. I took my truck to the local Chevy dealer, and they told me this normal. The brake pedal was normal before I started this job. I pressure bled, and buddy bled the system before I took it to Chevy. The next step I'll try, is to isolate the master cylinder, to see the what pedal does without the whole brake system. All suggestions are welcomed. Thank you
Sounds a lot like all the stuff I just replaced on my S10. It is possible that you have a bad part even though it’s new. Try bleeding the brakes with the engine running, that’s what worked for me and how I found the bad wheel cylinder. Or there could be just a little more air stuck somewhere that bleeding with the engine running and making use of the brake booster will get it out. Isolating each part in the system is also a good idea to try.
Forget the dealer, they don’t know about the older vehicles. If you have to take it somewhere, find a good local shop that works on older vehicles.
I gotta look at my brothers 99 Silverado this morning. Similar issue. It does stop, but that pedal is soft. I'm assuming somewhere around the wheel cylinder or a rusty brake line
Your great video led me to isolate the four corners of my car. I discover that the new calibres I had installed were boxed incorrectly and I had put them on the wrong sides with the bleeder valve faced down. Once I swapped them and bled them the brake pedal firmed right up. Thanks
Thank you so much for this post! I am also fighting the same issue on my 2001 s10 [4.3 v6] (we converted it to front/rear disc brakes)
>yes we installed 3 new master cylinders
>yes we installed new brake booster
>yes all lines are new , no leakes
(Yes i have a new proportion valve and the locking tool to keep the piston in place)
We heard engine idle changes while trying to compress the brakes, could the engine vacuum leake be another cause for our issue?
I just snapped and brke my pcv valve while trying to remove it. Tomorrow im going to install a new one.
I also plam on installing another set of beans calipers in the rear.
I plan on adding grease to the bleeder nipple to minimize air entrance issues.
Does this sound remotly accurate? Or am i wasting more time and money?
I figured this is a good approach because everything is custom at this point.
If you want photos i can email you.
Any help would be greatly appreciated. (I'm a welder/fabricator from Cleveland Ohio)
Did you figure it out?
Thank you Joe I'll be sure to check those. I Replaced master cylinder and rebuilt front calipers. pedal still go to floor slowly brake check valve ok and booster. 😡 Focus zx3 01'
THANKS Joe, for sharing! It's one of those problems that is good to know, especially if you HAVE it. It's surprising that even experienced mechanics would not know how to find the underlying cause.
i finally found the answer. having same problem with a honda civic 1987 si and crx i change the booster and master cilinder and when i started the engine pedal goes to the floor pain in the butt. but i keep tracking this issue until i fix it doing that. you won't see any leaks at all. but that is the problem.
Sweet!! Thanks For Your No Quit position! Way To Go!! Also, Thanks for Caring and Sharing!!
Could this happen to brake calipers as well, or just "wheel cylinders" that are found on drum brakes, I wonder. I also don't get why the brakes don't go the floor with the car off. It should still be leaking, I would think.
Very helpful!!! I’m having the same issue left rear constantly bleeding air out. Thank you for the video 👍🏼
Place clamps on three of the four flexible brake hoses, and then pump the brakes, which will engage only the brake that is not clamped. If the pedal force is good, then you found one good brake. Continue with the other brakes by moving the three clamps to isolate a different brake and repeat until you identify the faulty brake. Also, it's best to clamp the flex hose at the end that is furthest from the caliper, as the flex hose itself might have the leak or simply be weak.
Do you do this with car running or not? I have caliper in all 4 corners. Would this still apply? Is the faulty one going to produce a soft/ mushy pedal then? And if so, replace caliper? Thanks
I had a right near parking break cable that was crimped somehow. It caused that caliper to get hot and start leaking. My break fluid level got to the point where it gave me a warning. Added fluid, and the breaks still functioned normally. Replaced that right rear caliper and started having this exact problem. Now I am wondering if it is the new caliper that is causing it. I guess I will try bleeding it again in a few days to see if I get more air out of it.
Same problem with my 2004 Saturn ion. But I’ve replaced the wheel cylinders and the calipers and the master cylinder. I eventually got a hard pedal but when starting the car it goes down. No leaks around the ABS module. I’m suspecting the booster. Also the engine rpm drops when holding the pedal down. I’ve heard that can be caused by a faulty booster
Well you almost had my problem solved, the one I'm working on I did the same routine that you did except this one is 03 zr2 . Replaced the booster twice, master cylinder twice went through 2 gallon brake fluid still no brake pedal when motor is running.
I bought my 2006 Cevy Malibu FSE used and it drives like a dream! I've had it for 2 years now and I haven't changed the brakes/brake pads/etc yet not had any major issues. Since I'm not loosing brake fluid, but the pedal is going down to the floor & It has never done that before- Does that mean it's time to change the brakes/brake pads/rotors etc....?? Someone please help! Thanks! 😃
Check the fluid level in your reservoir. If it’s a little low that’s a sign your brake pads are worn (if there are no leaks) then check your brakes and top off the reservoir. If it’s really low you have a leak somewhere.
@@joestoe1610 If there is a leak, will a shop charge me an arm and a leg to find the leak?
@@joestoe1610 Thank you so much for the information and help sir! 😃
I don't have wheel cylinders, but have the exact issue. Firm pedal when the engine isn't running, soft and to the floor/mushy when the engine is on. I guess I should try the Master Cylinder - 2003 Jeep Grand Cherokee., 4.0L
Having same problem 1985 Toyota 4wd I have changed everything but the rear cylinders due to no leaks I’ll replace them sometime this week.
Working on the same truck with the same symptom, except not getting any air from the bleeders. Gonna see if an ODB1 scan tool has a procedure for bleeding th ABS assembly.
I ran into a similar issue on a 97 Yukon 4WD but the wheel cylinders were new. Brand new wheel cylinders on both sides and new drums and the pedal is rock soild until you turn the engine on. I bled everything you can possibly bleed over and over and over and ended up having to relinquish the job.
What turned out to be the problem?
@@joestoe1610 The ABS had air stuck in it. Required a GM Tech 2 scanner to bleed the air since my Autel Maxisys doesn't have that function on the pre-2001 GM vehicles for some reason.
Exact truck I've got right now
Hi, I installed a new JEGS brake booster and master cylinder in my 1977 Impala, but I have faced a problem. The brake performs well except sometimes when I push the brake, I lose it and feel the pedal sinking. Why does this happen?
There’s probably a leak somewhere. Check your fluid levels if they are going down.
I just bought this 2004 Suburban and I noticed the brake/ABS plug underneath the front passenger seat was unplugged. Soon as I plugged it up the 2 front brakes passenger /driver started dragging. I wonder if the previous owner unplugged the plug for that reason. To release the brakes I opened up the bleeder screw. And when I changed the brakes both passenger/driver side brakes was to the metal. Can having the ABS plugged up cause the brakes to drag? Leaving it unplugged will it help stop the dragging? BOTH SIDES ARE STICKING AT THE SAME TIME.
Replaced master cyl, booster, passenger side caliper (leaking) on a 98 Dodge ram 1500 (new caliper bleeder is up ) .....before doing this no warning indicators....bled breaks twice got a firm pedal engine off. Engine on, same problem at first... pedal all way to floor.
Pumped a few times got a firm pedal with engine on after a minute. Put in reverse to back out of driveway and pedal goes to floor...no brakes.
Drove down a less traveled road, stopped ok at a turnoff. turned around and no pedal again ..no brake! Drove back 1/2 mile to my driveway....stopped ok at intersection before turning off to my drive way, made a right turn into drive way and pedal again to floor...no brakes. Almost hit garage door, stopped by BBQ pit. Bled system again engine off , good pedal. Tried same drive test again same results except used E brake to save BBQ pit this time.:) Now getting ABS and Brake light warning.
Master cyl full, no leaks apparent. Last brake job was 10,000 miles back.....shoes all good....little wear.
Mike
Bled brakes again today 3rd time , little to no air bubbles noted. Solid pedal until put in reverse to back up and then go forward I lose the pedal again. About ready to put new rear wheel cylinders in at this point , they aren't expensive...also a new drivers side front wheel caliper just to eliminate that possibility.
ABS and Brake light still comes on after clearing with my scanner device. Beginning to suspect a bad ABS module and or pump.
I saw your solution above, glad you got it sorted out!
Had same issue with my Son's 07 Silverado & after replacing almost all brake parts, bleeding, bleeding , & replacing rear brake wheel seals ECT. pedal goes close to floor with engine running. I'll give a try with motor running & go from there. Thanks for posting this .
Update?
Question: how is the wheel cylinder leak related to the engine running or not?
The vacuum assist brake booster behind the master cylinder will almost pull it down to the floor when the engine is running if there is any air in the lines that will compress. When you press the brake pedal , it opens the check valve and allows the vacuum assist.
I would never have thought to change that. Great informative video thank you. It’s one to remember for future troubleshooting
I have the same exact issue with my Civic. I just changed the driver side rotor, caliper, and pads and my pedal sinks to the floor with the engine on and before I did anything my pedal was perfect. Maybe it's air that's causing it but I dont know. I can't drive anywhere in the condition it's in. I should have left everything alone and took my car to the shop to my brakes done. I'm not happy right now, I am not a mechanic but I've brake jobs before.
It’s most likely air if you replaced the caliper. Make sure you have the correct caliper on that side as they are interchangeable and if wrong you’ll never get the air out. Also bleed the whole system not just that wheel. Yes It’s a pain
I just did my rear brakes, all new parts, bags of parts and new shoes. Bled a half gallon of brake fluid out. Bench bled my master again. Pedal to the floor. But I still haven't bled to the front wheels. I saw one guy who plugged the master ports to see if it was good. My last step will be to take out the ABS. Looks very hard since I will have to learn how to bend brake lines.
That's a great video and it also answers a question of mine at the same time. I'm going to be replacing my calipers on my 2001 Dodge ram 1500 pick up. I noticed one of the pistons on the passenger side was crumbling and I knew it was going to be a problem later on. I spotted this because I had just changed my brake pads in the front. After changing the pads, I started up my truck, and pump the brakes to get a solid pedal back because I think that's the best way to get a pedal with the assistance of the booster. I just don't understand how people can complete the brakes and not have the engine running. Doesn't the pedal give you a tail sign that it's OK? It just doesn't seem right to me.
I have the same problem exactly on my 93 Typhoon. After replacing the same components that you did (except booster) I was about replace the booster. I read how much of a pain it is to replace on these vehicles, so I scanned youtube for an easier way to replace it. I came upon your video and decided to try your fix... I will let you know if it works when I am done.
did it work
@@blesdavis7637 He died
Actually the booster change isn’t that difficult to do.
@@LegendaryWokeyup, lack of braking power.
I dont understand how the wheel cylinder can "suck" air in, and yet not leak any fluid.....but in your case, the problem defied physics. I am going thru the same issues.....pedal goes to the floor when starting engine. I have replaced the Master B. C., the Booster, and bleed the brakes many times. No leaks anywhere. I also deleted the ABS system. On my Mit. Montero, there was a "return" line coming from the rear brakes to the ABS box. Should I have deleted this return line? I just routed the return rear line to a junction with the main MBC push line which went into a junction that fed brake fluid to all the brakes. Is this "Do-Loop" maybe my problem?
Thanks
I couldn’t believe it either at first! I would eliminate the return line altogether if it’s not needed.
I having the same issue with my kids 05 Altima. We replaced all 4 calipers and replaced the master cylinder 2 times. Bleeds fine, pedal gets hard when cars off but when I start it, I got a soft pedal...
I am having a similar problem with my 1998 Chevy Silverado when I first got the truck the first thing I did fix on it was the brake line and the brake lines that connect onto the rear brake drum cylinders, days go by and I get to change the springs and brand new rear brake cylinders on both rear wheels, went to put the front and installed both driver and passenger brake hoses. I later on bled the brakes and passenger rear had a good amount of air, moved on to the driver rear and it was the one with the most air but we got it good, went to the front two and they bled pretty good, after that brake would get more sturdy but if pressed past the pressure point it just sinks and it gets stuck. I though there was not pressure building up so i put in a brand new brake master cylinder and it is still sinking. I haven't changed the brake booster or the abs. Would it be one of them?
im having the same problem on my 2010 subaru forester and i don't have rear wheel cylinders . when sitting at a red light with my foot pressing on the brake pedal the pedal goes slowly to the floor... i replaced the master cylinder, benched bled the new one... bled the complete brake calipers...no leaks anywhere in the system but the brakes slowly goes to the floor...
also no brake fluid in the booster... booster works good..
Same issues with sequoia. Did you fix it? I have calipers in rear not drums
I don't recommend using grease on the bleeders. The fluid will dilute it very quickly. I clean the threads and wrap them a few times in teflon tape. Won't suck air in when you bleed and also won't rust sieze on you next time they need to servicing years down the line.
aint nobody got time for that sh t
Good idea, thanks. The grease trick has been working for me for a long time though, haven’t had rust problems yet.
There is a special grease made exactly for this purpose.
@@trailerparkcryptoking5213 would you tell me what it is?
I've just seen ur video .we'll I changed wheel cylinders .ever since I did I had thos issue brand new but the cheap cylinder changed all the brake lines master cylinder etc .ended up changing rear cylinder again . for decent quality ...hopefully when I connect everything g back up this issue will be fixed .thanks for your advice .
You just saved my day. Had this truck for 2 days now.
Great!
For my one all brake accessories such as master pump with booster, front caliper, rear cylinders all are brand new and still have the problem. Any ideas for that?
Oh
Awesome got the same problem with my gmc 07 Sierra
Check the ABS unit for air too.
Oh yes this helped. I pushed out the piston on both brake cylinders recently while changing my drum brakes. I have the same issue as you. I probably need to replace both cylinders.
THANK YOU - my Saturn2006 VUE just lost braking - went into a soft brake mode
so .. I had exactly the same problem with drive rear cylinder ay thank for your efforts !
I had this problem! I watched this video it saved my mind lol I changed both cylinders fixed the problem thank you!
My cylinder was leaking the rubber deal slid off to one side i noticed rust and a drip on inside wheel and drum rusty. Knew i had problem still frustrating though.
Hi Joe Stoe,
Thanks for sharing your experience with the brake pedal issue when the engine is started. It's valuable insights like yours that help us troubleshoot and solve problems. My parents have a 2013 Multivan, and this problem sounds familiar. I'll definitely be checking your suggestion on my van as soon as I get home today. Appreciate the heads up and any additional tips you might have!
Best regards,
I had just finished putting back brakes on my daughters Jetta. I replaced the wheel cylinders on both rear brakes, the passenger side had started to leak a few days ago. Anyway, I replaced them and put new shoes on. I still have a very soft brake when the car is turned on. I did not have the car running through when I bled the lines. I did all four wheels and got very little air. So, your suggesting I should have the car running when I bled the lines?
It could help. It’s not common practice to have the car running but it worked for me to have the assistance from the booster.
George the problem is in the combination valve, it thinks there is low pressure one side of the system, when you are bleeding it, and cuts the pressure from the master cylinder to it, this is a safety design in the combination.!. To where all brakes will not be lost if it is a loss in pressure, there is a special tool that screws into the combination valve, to hold it in place while bleeding, it will equalize all pressure to the wheels. You can get the little tool online for around $8.00 Bucks give it a try ...
@@tonywhitmire3721 Can you tell me what the tool is called and where exactly I put it?
Hi, my break down to floor when car is running. Break works ok but just soft and going to floor. I changed the master cylinder and booster but still the same. Machanic too does not know much. What will be possible solution?
Check the brake pads
@@isaiahbenton983 thanks bro
The pin inside the booster may need to be adjusted
Combination valve , safety mechanism is activating when you are bleeding brakes.!!!... Remove they light indicator combination valve, They make a little tool that screws into combination valve to hold it in place, while you bleed the brakes, ( here is an example on how they combination valve work's , a loss of pressure are low pressure the combination valve thinks there is a leak, they spring mechanism inside the valve will shut off pressure to front or the rear , to help from total loss of Brakes.
Wonder if that's my problem with my calipers, replaced master cylender after meticulously bench bleeding it. Left rear caliper keeps getting air with no fluid leak
Make sure they are on the correct side otherwise you’ll never get the air out of the calipers
Joe Stoe! I like that name sir!I have an issue .maybe you can help me or point me in the right direction!I have a 2008 chevy express 2500.I get a, or have a soft brake pedal.So I inspected everything, calipers, master cylinder, hoses and lines, etc.... No leaks.So then I would bleed the brakes and I would have a hard brake ,stiff pedal for a few months, then the peda would get soft again.Bleeding helps but just for a few months.Oh, I get what sounds like the the abs system activating when you are sliding on snow or ice during routine driving.it only does it for a few seconds when the vehicle comes to a stop.Is this related to my soft pedal ? Help anyone. I did just replace my power steering reservoir cause it was leaking fluid through the rusty reservoir body.I'm pretty sure air got in the lines but I wouldn't think that would affect the brake/ hydro boost system / function? 🤔 🗣" Helllppppp!!!!""🥺
I don’t know but someone else might. I would check for an ABS code first and then bleed the ABS unit. Can they leak internally? You might have to take it to a shop for that.
@@joestoe1610 ok joe.I don't have any abs codes but I'll look into it.I bled the brakes last weekend and now I have good brakes, toe touch tight!!! I talked to the guy I take my cars to when I can't figure it out myself,and he said to see if the master cylinder is leaking internally sucking air somehow.🤷🏽♂️ . My mechanic buddy said its not the hydroboost because it would would create a hard pedal if it was malfunctioning.... I'll replace the master cylinder and see what happens. Thanks Joe Stoe!!!
I've had that exact same issue. Ive also has bleeder valves leaking through the thread's.
Complete nightmare trying to diagnose the problem lol
Yes, I sometimes put a little grease on the bleeder after its in to seal it to see if thats the problem
I replaced some brake lines in my 2005 GMC Jimmy and had the same problem. The ABS had air in it so engine off I would push the pedal down with a stick, then loosen the abs line at the abs and let air out, then tighten, release pedal and press it again holding it in with the stick. Just like bleeding the brakes at the wheel. Lots of air came out and that was the problem.
I have this problem but don't think i have a brake cylinder. My rear rotors are drum + disk.
02 Jeep Grand Cherokee Laredo 4.7L V8 VIN-N Selec-Trac SOHC.
My pedal goes almost to the floor before i get brakes and they work but are weak.
No visible leaks at calipers or in wheels or at master cylinder. Pads look like they have at least over half pad left..
Maybe im leaking fluid from master cylinder into power brake booster but not sure.
I do have missing brake fluid that went below min mark. It doesn’t leak fast, it was 5+ months before i had brake light on with low fluid in master cylinder reservoir.
I just dumped what i had left of DOT3 but its only up to minimum.
Ill order 5x 12oz bottles soon with a bleeder bottle kit so i can do it myself. One of thw brands Allstar has a one way chwck valve on bottle so you can't get air in brake lines.
Let me know if you know what this is?
As the pads wear out it will take more fluid to operate the system so topping off might help if you don’t have any leaks.
Same problem on a 98 Corolla the whell cylinders never leaked but sucked air bad . Finally checked them soon i touch the rubber boot they poured fluid .
Do you need to open the ABS unit with the computer , open the valve chambers where the air hides????????