I’ve watched several other leak down test videos but when I watched this one I finally understand how the test works. EXCELLENT INSTRUCTIONAL VIDEO !!!
Hey Mark, took your Ignition course in Pittsburgh. Just want to say awesome video and tech tip. You and all the Garage Gurus are literally that - Gurus! Thank you for all the valuable knowledge 👍
Wow, someone that actually knows how to perform a cylinder leak down test. Almost every video on TH-cam is WRONG. It’s nice to see someone do it right. Thank you.
You still should in many cases. A compression test confirms if the cylinder builds compression, a leak down test shows if it holds that compression pressure.
If you started at 90psi in the inlet, how does it go up to 92 percent, if anything it should go down; right? I don't understand how it's a 5-6% leakage. Please clarify.
The engine might spin because of the cylinder being pressurized by the test equipment. Similar to what happens on the usual power stroke but at a much, much lower torque. And of course, which way it would spin depends on if the piston was before or after TDC. More of a concern with a standard transmission since the car could lurch if being in gear was holding the engine and no one was stepping on the brake. In an automatic transmission situation, the car won’t move, but the engine might, making the test fiddly since you have to find TDC again. Hence the breaker bar (not a ratchet!) on the crank pulley to hold the engine in place.
Tdc marks should be located on the crank itself. However you can put a balloon on top the hose to watch it blow up then you'll know your close. Hope that helps.
So basically if I am wanting to buy a used car, and I went to a supposed mechanic, I don't want this test done. Because if the person is pretending they are a Mechanic, they will damage what may have been a good engine!
I’ve watched several other leak down test videos but when I watched this one I finally understand how the test works. EXCELLENT INSTRUCTIONAL VIDEO !!!
Best video of this topic on TH-cam
I have been looking for information about this and after several confusing videos, this one finally helped me to understand how it works. Thanks 👍
Hey Mark, took your Ignition course in Pittsburgh. Just want to say awesome video and tech tip. You and all the Garage Gurus are literally that - Gurus! Thank you for all the valuable knowledge 👍
Wow, someone that actually knows how to perform a cylinder leak down test. Almost every video on TH-cam is WRONG. It’s nice to see someone do it right. Thank you.
Woah, I saw you from the snap on red leak down tester video. I can now test my mower properly thanks to people like you and Mark🤝🏼
I use the balloon method to determine when the pistons on its compression stroke.
Buen video exelente explicacion
A todos los motores se les puede aplicar 100 psi ?
Gracias x su respuesta
Si
Super helpful video and everything clearly explained. Thanks!!
Thanks for the sharing the vid, very informative 👍👍
Excellent....clear and to the point.
If you have good compression from compression test then does that mean you wouldn’t need to do a leak down test?
You still should in many cases. A compression test confirms if the cylinder builds compression, a leak down test shows if it holds that compression pressure.
If you started at 90psi in the inlet, how does it go up to 92 percent, if anything it should go down; right? I don't understand how it's a 5-6% leakage. Please clarify.
Thank you, very informative
Why would the engine spin because of the ratchet? I am sorry if this is a stupid question I want to perform this test but have never done it before.
The engine might spin because of the cylinder being pressurized by the test equipment. Similar to what happens on the usual power stroke but at a much, much lower torque. And of course, which way it would spin depends on if the piston was before or after TDC. More of a concern with a standard transmission since the car could lurch if being in gear was holding the engine and no one was stepping on the brake. In an automatic transmission situation, the car won’t move, but the engine might, making the test fiddly since you have to find TDC again. Hence the breaker bar (not a ratchet!) on the crank pulley to hold the engine in place.
I have a 4 cylinder in my car. Would I need to check all 4 and if so do I take out one plug at a time or take all 4 out then do the test?
1 at a time
Awesome video!!
Do u have to disconnect the upper radiator hose to do this test?
Nah. Bubbling through the radiator would tell the same thing
Very helpful demon stration thanks alot
What about if you hear air from the oil cap ?
Piston rings
At TDC is the air puff coming out of the hose strong? I need to do this on a 351 Windsor. Never done it before but I have the tester.
Tdc marks should be located on the crank itself. However you can put a balloon on top the hose to watch it blow up then you'll know your close. Hope that helps.
What about middle and bottom Dead center? The only reason why I say that is because taper in the cylinder wall ?
Taper occurs at the top of the cylinder
So basically if I am wanting to buy a used car, and I went to a supposed mechanic, I don't want this test done. Because if the person is pretending they are a Mechanic, they will damage what may have been a good engine!