Leak Down Test
Race Director
Joined: Feb 2004
Posts: 12,517
Likes: 19
1) Warm engine
2) remove all plugs
3) put piston you are checking at tdc
4)screw in fitting and put 100 psi air
5) Read the guage and log the number
Motor may try to roll over with all plugs removed. Some guys like to do 1 at a time but it is harder to roll motor over (by hand) to put piston at tdc.
Edit: tdc on compression stroke to ensure both valves are closed.
2) remove all plugs
3) put piston you are checking at tdc
4)screw in fitting and put 100 psi air
5) Read the guage and log the number
Motor may try to roll over with all plugs removed. Some guys like to do 1 at a time but it is harder to roll motor over (by hand) to put piston at tdc.
Edit: tdc on compression stroke to ensure both valves are closed.
Thread Starter
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Originally Posted by Pete K
1) Warm engine
2) remove all plugs
3) put piston you are checking at tdc
4)screw in fitting and put 100 psi air
5) Read the guage and log the number
Motor may try to roll over with all plugs removed. Some guys like to do 1 at a time but it is harder to roll motor over (by hand) to put piston at tdc.
Edit: tdc on compression stroke to ensure both valves are closed.
2) remove all plugs
3) put piston you are checking at tdc
4)screw in fitting and put 100 psi air
5) Read the guage and log the number
Motor may try to roll over with all plugs removed. Some guys like to do 1 at a time but it is harder to roll motor over (by hand) to put piston at tdc.
Edit: tdc on compression stroke to ensure both valves are closed.
Le Mans Master
Joined: Feb 1999
Posts: 6,172
Likes: 11
From: somers, ny
It's not time sensitive. the tester will have two guages: one showing applied pressure and the other showing the cylinder pressure. If you use 100psi source, then the leakdown % will be the difference between the source and the cyl.
