Tools Required

SA9127E Cylinder Leakage Tester

Caution: Cylinder leakage checks must be performed with the vehicle in park or neutral and the parking brake applied.

If there is lack of power, excessive oil consumption or poor fuel economy, etc., cylinder leakage can be measured.

1. Start the engine and allow it to reach normal operating temperature.
2. Shut engine OFF and disconnect the ignition module connector.
3. Disconnect all the spark plug wires and remove the plugs.




Important: The piston must be located at exactly top dead center (TDC) or the crankshaft will rotate when air pressure is applied.

4. Rotate the crankshaft so each cylinder to be checked is at TDC. Timing marks are located on the front cover and vibration damper assembly for TDC verification. Access to the front crankshaft damper bolt can be achieved from the top of the vehicle with an open end wrench. A 3.175 mm (1/8 in) brass rod can be inserted through the spark plug hole to determine piston location relative to TDC.



5. Attach an air supply to the SA9127E . Desired regulator "In" minimum pressure is 861 kPa (125 psi), maximum is 1 034 kPa (150 psi).
6. Insert the cylinder leakage adapter in the spark plug hole with the piston at TDC.

Important: If the crankshaft rotates, the piston was not at TDC. The crankshaft will have to be relocated at TDC.

Important: Make sure all cylinder leakage adapter fittings are tight and the piston is at TDC or incorrect readings will be obtained. Check lower cylinders.

7. Close the gate valve and adjust the regulator pressure to 689 kPa (100 psi). Open the gate valve. Observe the crankshaft during this operation.

7.1.	Allow 60 seconds for the air pressure in the cylinder to stabilize. Observe the cylinder pressure gage and record the pressure.





7.2.	Listen for escaping air at the throttle body air inlet, oil fill cap, exhaust outlet.

7.3.	Remove the coolant bottle pressure cap and look for bubbles.




8. Repeat previous steps on other cylinders. Record the readings.

•	Cylinder 1 equals gage reading 65

•	Cylinder 2 equals gage reading 65

•	Cylinder 3 equals gage reading 140

•	Cylinder 4 equals gage reading 60

-	Normal Cylinder Leakage: 10 percent - 69 kPa (10 psi)

-	Maximum Leakage: 20 percent - 138 kPa (20 psi)

-	Difference Between Cylinders: 5 percent - 34 kPa (5 psi)

9. Remove the cylinder leakage tester and install the spark plugs.

Tighten
Tighten the spark plug-to-head 27 N·m (20 lb ft).

10. Connect the spark wires. Ensure the spark plug boots are firmly seated.
11. Connect the ignition module connector.