SilverSmoke

Coming from my other thread about possibly having a broken ring on #7 and god knows what else, I need to find a cheap leak down tester really quick. I have harborfreight a few miles from me and they sell one for a decent price, but the pressure only goes up to 100 psi. Will this work? I'm thinking the pressure needs to get up to at least 160-200 psi no??

HotSilverBird

LOL no 100 psi is the standard pressure used to do a leak down test.

SilverSmoke

Ok thanks!

Without tearing everything down on top, any way to get the piston to TDC to perform the test, or does it really matter? I heard that sometimes when your blowing air into the cylinder the piston is going to move and push the valves closed and then will build pressure...? I dunno I'm a newb to this area of investigation so be gentle.

HotSilverBird

Getting the piston on tdc is easy. One way is to pull the spark plug and use a socket and rachet to turn the engine clockwise looking from the frt. hold a finger over the spark pulg hole and you will feel it build pressure as it gets to the top. You can also use a small rubber hose in the spark plug hole to feel the top of the piston. If you leave all the spark plugs in except the one cylinder you are testing you should not have to worry about the engine turning over BUT if you plan on removing all the spark plugs then doing testing be prepared for the engine to turn over when you apply air pressure to each cylinder!

Damian

iTrader: (89)

Yes you can. I have a back up tool from HF just in case my matco tester breaks or I've loaned it out. I've used the HF tool twice before on LS engines, and it works fine.

Fill the cylinder up with 100psi, and see how much leaks down. If you get leak down to 80psi, then you've got 20% leak down in that cylinder.