Service Diagnosis & Repair Procedure

Read the instructions in this bulletin carefully. Refer to the appropriate diagnostic flow chart to repair the vehicle.

1. Perform a visual inspection to determine the general area of the leak.

2. Perform Step 3 by following Procedure "A", B", "C", or "D" up to but not including the "Air Pressure Test".

NOTE:
If Procedure "D" is to be followed for repair of "Oil Leak At The Rear Seal Area", the engine must be removed. Removing the pan with the engine in the vehicle can result in faulty repair.





3. If the exact location of the leak can not be found using the Oil Leak Location" flow chart, use the air pressure tester tool (pin 49 U0-14-001) (shown at right) to apply 1 - 3 PSI of low pressure air to the crankcase.

4. Verify the location of the leak by pressurizing the engine crankcase with a constant supply of 3 PSI of air.

^ Test the tool to make sure 1 - 3 PSI of air pressure can be maintained. Bursts of air over 3 PSI can cause engine damage.

^ Close tool's pressure regulator valve completely.

^ Attach the air supply to the pressure tester. Attach the tester to the engine.

^ Plug any ports or passages (PVC, air inlet) that will allow air to escape.

^ Slowly open the regulator valve until 1 - 3 PSI of air pressure registers on the gauge.

^ Brush or squirt a commercially available leak detector to the primary area identified in step 2.

5. If the primary area is the rear seal area, apply the leak detector solution to the rear seal, rear cap, rear cap to cylinder block and oil pan areas.

^ If the bubbles are detected only at the oil pan gasket, between the oil pan and the cylinder block or between the oil pan and the rear main cap, only the oil pan and gasket need replacing. Note Procedure "D", Step D5/F1 and the illustration under findings F1. Proceed to repair procedure D1 in the Oil Leaks At Rear Of Engine section.

^ If bubbles are detected between the rear main cap and the cylinder block, the rear main cap must be removed and resealed. Note Procedure "D", Step D5/F2 and the illustration under F2. Proceed to repair procedure D3 in the Oil Leaks At Rear Of Engine section.

^ If bubbles are detected between the rear seal lip and crankshaft hub, a new rear main sleeve kit will be required. Note Procedure D", Step D5/F3 and illustration under F3. Proceed to repair procedure D3 in the Oil Leaks At Rear Of Engine section.

^ If no bubbles are present but oil is present in the area between the crank hub and the lip of the rear seal, carefully remove the rear seal and inspect the crankshaft rear seal journal (a leak may a occur at the rear seal only when the engine is running). Note Procedure "D", Step D5/F3 and illustration under F3. Proceed to repair procedure D5 in the Oil Leaks At Rear Of Engine section.

NOTE:
Any appearance of rust, pitting, porosity or nicks on the rear seal journal will cause a leak.

6. If the bubbles are detected at the front or rear of the intake manifold, the intake manifold gasket will need to be replaced.Proceed to Service Procedure B", Oil Leaks At Intake Manifold.

7. If the bubbles are detected at the rocker arm cover(s) rails, the rocker arm cover gasket(s) will have to be replaced. Proceed to Service Procedure "A", Oil Leaks At Leaks Oil At The Rocker Arm Cover(s).

8. If bubbles are detected at the front of the engine, a new front seal or oil pan gasket will be needed. Proceed to Service Procedure "C", Oil Leak At Front Of Engine.