The combustion pressure leakage test provides an accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
Exhaust and intake valve leaks (improper seating)
Leaks between adjacent cylinders or into water jacket
Any causes for combustion and/or compression pressure loss
1. Check the coolant level and fill as required. DO NOT install the radiator cap.
2. Start and operate the engine until it attains normal operating temperature.
3. Turn the engine OFF.
4. Remove the spark plugs.
5. Remove the oil filler cap.
6. Remove the air cleaner hose.
7. Calibrate the tester according to the manufacturer’s instructions. The shop air source for testing should maintain a regulated air pressure at 552 kPa (80 psi).
8. Perform the test procedures on each cylinder according to the tester manufacturer’s instructions. Set the piston of the cylinder to be tested at TDC compression.
9. During the testing, listen for pressurized air escaping through the throttle body, tailpipe and oil filler cap opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal, with no more than 25% leakage.
FOR EXAMPLE: Input air at 552 kPa (80 psi), the primary gauge factory set at 207 kPa (30 psi) input pressure. The secondary gauge should have no more than 176 kPa (25.5 psi) loss, when connected to the cylinder.