Wow! I did not know it was that easy! I have most of the materials to build it in my shop! Thank you for this DIY tip. I have wanted a leakdown tester for home & hobby small engine work, but couldn't afford one. Now, I can, 👍 Paul
Thanks for watching. It is a fairly simple and cheap project compared to what one cost retail. I have an old snap-on leak down tester I bought at an estate sale a couple years ago. My DIY version gets the same results as the snap on unit. Maybe one day I’ll make a comparison video. Good luck with your project!
the odds, cleaned out junk draw yesterday threw all these parts a way. today pricing out leak down tester...came across this video......wife walked into the kitchen seen me digging through the trash. should of seen her reaction seeing me tearing garbage can apart, priceless !!!! thanks for the tip on build dirty hands, clean money.
Excellent tip for wrapping the teflon tape and holding the pipe in your right hand. I always have to think about it but that makes it so easy to remember!
Wow! This is the best, clearest instruction on a DIY leakdown tester I’ve found and I’ve watched many! From such a small channel, too! Thanks a lot - great job! 👍🔧
Wow! I had all of the parts within 6 feet of where I'm sitting. Even the drill bit. I was looking at this stuff just yesterday, wondering if I should Trash 'em or keep 'em. For once, I was ahead of the "Murphey's Law" subclause that states that " You will not need the item until two weeks after you toss it". What's even better is, I had put a Leak Down Tester (cheap Chinesium version) in my watchlist on eBay, got an offer for less, which prompted me to look a bit further into it on TH-cam, and here I am. Ahead of the game again, with left over, BRASS parts, no less. (except for the regulator) It's even dry fitted together already except for sealing the threads, putting epoxy in the nipple and drilling. (I may just take the time and polish it all up and make it "Shiney".) Man, Thanks so much for posting this video. You totally made my whole day TWICE in less than 15 minutes! You helped me reduce some of my clutter AND saved me $40. (Winner, Winner, Steak Dinner! (forget all about chicken)). Have a great day, take care and Thanks Again!!!
Glad to hear the video was of some help and saved you some $$$. I have used mine several times and it’s just as accurate as the Snap-On leak down tester gathering dust in my tool box. As I tell my wife..it’s not clutter, it’s an unassembled project. Thanks for watching and keep an eye out for new content.
This is excellent - what I did not understand is why you need a restriction between regulator gauge and pressure gauge. If there is no leak, both will read full pressure, and if there is a leak, the pressure gauge will still reduce in pressure while regulator tries to maintain full pressure....? Having thought about it while writing this, I can see the restriction being useful to maintain full pressure on regulator when you have a massive leak - is that kind of right?
Yes, the restriction allows for a pressure differential between the two gauges so we can quantify the loss of pressure. It also restricts the volume of air. You’re correct, without a restriction a small leak would be measurable but a large leak will result in the pressure gauge going to zero or near zero. The restriction reduces the volume of air getting into the cylinder and makes it a controlled leak and allows the pressure gauge to stabilize.
You need the restriction to give a measurable pressure drop....in effect the restriction turns the device into a flow meter. With a good cylinder and almost no flow, the pressure drop across the restriction is close to zero so the two gauges show nearly the same reading. For a leaky cylinder, air flow rate is high which results in a big pressure drop across the restriction and so the two gauges show a big difference. It's the difference in pressure on the two gauges that you use for diagnosis. Without the restriction...or with too big a hole (more than 1mm diameter)...there is very little pressure drop and so the two gauges show the same reading regardless of flow rate. I bought a cheap gauge and it had a 2.5mm hole and showed no pressure drop regardless of how much air flowed. I had to modify it to bring the hole size down to 1mm. As an aside, once you've identified a bad cylinder and want to trace the leak, you're better off removing the leak down tester and connecting the air line direct to the cylinder. This will allow much higher flow rates and make it easier to feel or hear where the air is leaking out.
When I know there is a dead cylinder or i have isolated a problem to one cylinder, I won’t waste time with the tester. I will apply air directly to cylinder at 100psi. I knocked the porcelain out of a spark plug and welded an air fitting to it. Cheap tool and makes it easy to connect an air hose.
I don’t recall exactly what size I used, but a 1/16” bit will work. I use number drills a lot for machine work that are measured in thousandths of an inch instead of fractions. I have a bunch of them laying around making them an easy grab. If I recall correctly I used a #53 or #54 and they are both just slightly smaller than a 1/16th. Thanks for watching and I hope you build a leak down tester. Prices today are quite a bit higher than 2019 but you should be able to put something together for about 25 bucks using HF stuff.
I assume you are asking about the quick disconnect hose. The hose is from my compression tester set. Most compression testers use a hose like this. If you dont have one already it is an additional expense and it will push the cost of this project higher. IF you dont have one and you want to diagnose engine condition you need one anyway. These prices were from 2019 so it may be hard to find all these parts for the same price. www.harborfreight.com/automotive/auto-shop-tools/compression-pressure-testers/compression/quick-connect-compression-tester-62622.html
As air passes through the restriction from the high pressure side, the pressure drops. The installed gauge allows us to see the pressure differential between the supply side and the leaking cylinder. A cylinder leak down test can be accomplished by applying static air pressure to the cylinder without a gauge, then listening for air coming out of intake, exhaust, etc. This is great for finding a gross defect in an engine but without a gauge we can’t determine the severity of the leak. A Leak down tester allows us to quantify the leak and compare readings cylinder to cylinder and against specifications. Not a fluid dynamics guy but I hope that explanation helps. Thanks for watching !
Thanks mate, appreciate it, i have a cheap leak down tester now, however i find it anoying to dial it in within the "set" range, aswell as it normally is in the set range with the reg set around 20psi. I might swap the gauges on the manifold so i can just set the reg to 100spi, can you see an issue with that? I presume inside my current tester manifold its restricted, if not i can epoxy and drill a 1mm hole.
@@ybsadfor the 20 psi leak down testers are touchy, I find they work best for small engines like on lawn mower. Swapping the supply gauge out for 100 psi should work as long as the regulator is rated for that pressure. You’ll know pretty quick if it’s not, you won’t be able to adjust pressure. There should already be a restriction inside the manifold.
Thanks for watching. This video was made in 2018 when things were a little cheaper. I suppose I could change the title to reflect current pricing. I spent less than 10 dollars out of pocket to assemble this tester using random parts I had on hand like the quick coupling, the hose from my compression tester, a gauge off my old compressor. I had to purchase the Air Regulator, the galvanized tee and the close nipple. I assumed most people willing to build this would have the compression tester already for the hose and a quick connector for the air compressor. I just looked up the prices for a regulator with gauge (5.99), a 160psi gauge (6.99) and a quick connect set (4.99) from harbor freight and a galvanized tee (1.77) and close nipple (1.40) from Home Depot for a total of 21.14.
Wow! I did not know it was that easy! I have most of the materials to build it in my shop! Thank you for this DIY tip. I have wanted a leakdown tester for home & hobby small engine work, but couldn't afford one. Now, I can, 👍 Paul
Thanks for watching. It is a fairly simple and cheap project compared to what one cost retail. I have an old snap-on leak down tester I bought at an estate sale a couple years ago. My DIY version gets the same results as the snap on unit. Maybe one day I’ll make a comparison video. Good luck with your project!
the odds, cleaned out junk draw yesterday threw all these parts a way. today pricing out leak down tester...came across this video......wife walked into the kitchen seen me digging through the trash.
should of seen her reaction seeing me tearing garbage can apart, priceless !!!!
thanks for the tip on build
dirty hands, clean money.
Thanks for watching. Happy you found it useful and good luck with your project!
Excellent tip for wrapping the teflon tape and holding the pipe in your right hand. I always have to think about it but that makes it so easy to remember!
Wow! This is the best, clearest instruction on a DIY leakdown tester I’ve found and I’ve watched many! From such a small channel, too! Thanks a lot - great job! 👍🔧
Thank you, I appreciate the comment. Thanks for watching!
Wow! I had all of the parts within 6 feet of where I'm sitting. Even the drill bit. I was looking at this stuff just yesterday, wondering if I should Trash 'em or keep 'em. For once, I was ahead of the "Murphey's Law" subclause that states that " You will not need the item until two weeks after you toss it".
What's even better is, I had put a Leak Down Tester (cheap Chinesium version) in my watchlist on eBay, got an offer for less, which prompted me to look a bit further into it on TH-cam, and here I am. Ahead of the game again, with left over, BRASS parts, no less. (except for the regulator) It's even dry fitted together already except for sealing the threads, putting epoxy in the nipple and drilling. (I may just take the time and polish it all up and make it "Shiney".)
Man, Thanks so much for posting this video. You totally made my whole day TWICE in less than 15 minutes!
You helped me reduce some of my clutter AND saved me $40. (Winner, Winner, Steak Dinner! (forget all about chicken)).
Have a great day, take care and Thanks Again!!!
Glad to hear the video was of some help and saved you some $$$. I have used mine several times and it’s just as accurate as the Snap-On leak down tester gathering dust in my tool box. As I tell my wife..it’s not clutter, it’s an unassembled project. Thanks for watching and keep an eye out for new content.
This is excellent - what I did not understand is why you need a restriction between regulator gauge and pressure gauge. If there is no leak, both will read full pressure, and if there is a leak, the pressure gauge will still reduce in pressure while regulator tries to maintain full pressure....?
Having thought about it while writing this, I can see the restriction being useful to maintain full pressure on regulator when you have a massive leak - is that kind of right?
Yes, the restriction allows for a pressure differential between the two gauges so we can quantify the loss of pressure. It also restricts the volume of air. You’re correct, without a restriction a small leak would be measurable but a large leak will result in the pressure gauge going to zero or near zero. The restriction reduces the volume of air getting into the cylinder and makes it a controlled leak and allows the pressure gauge to stabilize.
You need the restriction to give a measurable pressure drop....in effect the restriction turns the device into a flow meter. With a good cylinder and almost no flow, the pressure drop across the restriction is close to zero so the two gauges show nearly the same reading. For a leaky cylinder, air flow rate is high which results in a big pressure drop across the restriction and so the two gauges show a big difference. It's the difference in pressure on the two gauges that you use for diagnosis. Without the restriction...or with too big a hole (more than 1mm diameter)...there is very little pressure drop and so the two gauges show the same reading regardless of flow rate. I bought a cheap gauge and it had a 2.5mm hole and showed no pressure drop regardless of how much air flowed. I had to modify it to bring the hole size down to 1mm.
As an aside, once you've identified a bad cylinder and want to trace the leak, you're better off removing the leak down tester and connecting the air line direct to the cylinder. This will allow much higher flow rates and make it easier to feel or hear where the air is leaking out.
@markjones3121 well said.
@@markjones3121 Good info - like the idea of directly hooking up airline for extra air to identify leak location.
When I know there is a dead cylinder or i have isolated a problem to one cylinder, I won’t waste time with the tester. I will apply air directly to cylinder at 100psi. I knocked the porcelain out of a spark plug and welded an air fitting to it. Cheap tool and makes it easy to connect an air hose.
What drill bit do you use to bore out the hole?
I don’t recall exactly what size I used, but a 1/16” bit will work. I use number drills a lot for machine work that are measured in thousandths of an inch instead of fractions. I have a bunch of them laying around making them an easy grab. If I recall correctly I used a #53 or #54 and they are both just slightly smaller than a 1/16th. Thanks for watching and I hope you build a leak down tester. Prices today are quite a bit higher than 2019 but you should be able to put something together for about 25 bucks using HF stuff.
Hey brother can you explain that quick disconnect i cant find one like that
I assume you are asking about the quick disconnect hose. The hose is from my compression tester set. Most compression testers use a hose like this. If you dont have one already it is an additional expense and it will push the cost of this project higher. IF you dont have one and you want to diagnose engine condition you need one anyway. These prices were from 2019 so it may be hard to find all these parts for the same price. www.harborfreight.com/automotive/auto-shop-tools/compression-pressure-testers/compression/quick-connect-compression-tester-62622.html
Thanks
Hey mate, what's the reason for the restriction between the 2 gauges?
As air passes through the restriction from the high pressure side, the pressure drops. The installed gauge allows us to see the pressure differential between the supply side and the leaking cylinder. A cylinder leak down test can be accomplished by applying static air pressure to the cylinder without a gauge, then listening for air coming out of intake, exhaust, etc. This is great for finding a gross defect in an engine but without a gauge we can’t determine the severity of the leak. A Leak down tester allows us to quantify the leak and compare readings cylinder to cylinder and against specifications. Not a fluid dynamics guy but I hope that explanation helps. Thanks for watching !
Thanks mate, appreciate it, i have a cheap leak down tester now, however i find it anoying to dial it in within the "set" range, aswell as it normally is in the set range with the reg set around 20psi. I might swap the gauges on the manifold so i can just set the reg to 100spi, can you see an issue with that? I presume inside my current tester manifold its restricted, if not i can epoxy and drill a 1mm hole.
@@ybsadfor the 20 psi leak down testers are touchy, I find they work best for small engines like on lawn mower. Swapping the supply gauge out for 100 psi should work as long as the regulator is rated for that pressure. You’ll know pretty quick if it’s not, you won’t be able to adjust pressure. There should already be a restriction inside the manifold.
Solder works better than epoxy.
Solder would certainly work. Thanks!
Lost me at the channelocks to tighten pipe fittings 8:27
👍Channel locks aka pump pliers are used everyday to tighten pipe fittings.
Never can you build for 10 bucks , the air regulator costs that alone more bs
Thanks for watching. This video was made in 2018 when things were a little cheaper. I suppose I could change the title to reflect current pricing. I spent less than 10 dollars out of pocket to assemble this tester using random parts I had on hand like the quick coupling, the hose from my compression tester, a gauge off my old compressor. I had to purchase the Air Regulator, the galvanized tee and the close nipple. I assumed most people willing to build this would have the compression tester already for the hose and a quick connector for the air compressor. I just looked up the prices for a regulator with gauge (5.99), a 160psi gauge (6.99) and a quick connect set (4.99) from harbor freight and a galvanized tee (1.77) and close nipple (1.40) from Home Depot for a total of 21.14.