Tools Required
Important: A leakage test may be performed in order
to measure cylinder/combustion chamber leakage. High cylinder leakage may indicate
one or more of the following:
• | Worn or scored cylinder bore. |
• | Damaged cylinder head gasket. |
• | Cracked or damaged cylinder head. |
• | Cracked or damaged cylinder block. |
Caution: Refer to Battery Disconnect Caution in the Preface section.
- Disconnect the battery ground cable. Refer to
Battery Negative Cable Disconnection and Connection.
- Remove the spark plugs. Refer to
Spark Plug Replacement.
- Rotate the crankshaft to place the piston in the cylinder being tested
at Top Dead Center (TDC) of the compression stroke.
- Thread the
J 39313 into the spark
plug hole.
- Install the
J 35667-A or equivalent.
Important: It may be necessary to hold the crankshaft
balancer bolt to prevent the engine from rotating.
- Apply air pressure to the
J 35667-A J 35667-A
and adjust according to the manufacturers instructions.
- Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent
is considered above acceptable and may require component service. In above acceptable
leakage situations, inspect for the following conditions:
• | Air leakage sounds at the throttle body or air inlet hose may indicate
a worn or burnt intake valve or a broken valve spring. |
• | Air leakage sounds at the exhaust extension pipe may indicate a worn or
burnt exhaust valve or a broken valve spring. |
• | Air leakage sounds from the crankcase, oil level indicator tube, or oil
fill tube may indicate worn piston rings, a damaged piston, a worn or scored cylinder
bore, a damaged cylinder block or a damaged cylinder head. |
• | Air bubbles in the cooling system may indicate a damaged cylinder head
or a damaged cylinder head gasket. |
- Perform the leakage test on the remaining cylinders and record the values.