Leak down test
12-08-2010, 03:24 PM
#5
Pull a couple spark plugs on each side, or all of them if you want to.
Pull the FUEL PUMP fuse and turn the engine over for a few seconds after pulling it to get all remaining fuel out of the line so you know the engine cannot start.
Attach the tool to a spark plug hole, put the piston at Top Dead Center by bumping the key until the tool tells you its there.
Then fill that cylinder with compressed air through that tool and watch how much leaks down. You read the air pressure guage to watch the drop.
Thats it. I watched someone do it on mine like 7 years ago and thats what he did.
.
Pull the FUEL PUMP fuse and turn the engine over for a few seconds after pulling it to get all remaining fuel out of the line so you know the engine cannot start.
Attach the tool to a spark plug hole, put the piston at Top Dead Center by bumping the key until the tool tells you its there.
Then fill that cylinder with compressed air through that tool and watch how much leaks down. You read the air pressure guage to watch the drop.
Thats it. I watched someone do it on mine like 7 years ago and thats what he did.
.
12-09-2010, 12:10 AM
#6
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Remove spark plugs. A leakdown tester wil have 2 gauges on it. One is incoming pressure and the other is leakage in the cylinder. Rotate engine to top dead center on the COMPRESSION stroke on the cylinder you are testing. Install tool to cylinder in spark plug hole. Connect shop air to tool. Set regulator to 100 psi and look at 2nd gauge and read pressure. Typical leakdown is less than 10% but I wouldnt be alarmed if it was up to 20%. It will change depending on if engine is cold or hot. If leakage is excessive, listen and feel for where the air is coming out. If its coming from the throttle body or exhaust, you have a valve problem or they arent closed. If its coming from the crankcase, you have a ring problem. Also, when you apply the air to any cylinder, its going to more than likely push the piston down. Have a friend hold the crank stationary with a breaker bar so if it does rotate you will be ready for it.