Fuel Leak Diagnosis - Inside of Engine

Fuel Leaks (Inside of Engine)

IMPORTANT: If you were directed here from Fuel Return System Diagnosis, go to step 15. This will be performed with the same components disconnected as stated in that test.




1. Disconnect the fuel return line (1) at the engine.
2. Remove the air duct from the air cleaner assembly to the turbo inlet.
3. Remove the air intake pipe.




4. Remove the fuel return rubber hose of the fuel injection pump from the junction block (2). Cap the fitting on the block with a 3/8 inch rubber cap (1) to prevent fuel leakage.
5. Install the J 23738-A Vacuum Pump at the fuel return pipe.
6. Apply 15 inches Hg of vacuum to the pipe.
- If the vacuum holds, reinstall the disconnected components and go to step 22.
- If the vacuum does not hold, go to step 7.
7. Remove the generator.




8. Disconnect the fuel return line (1) from the right front cylinder head.




9. Install a black hose (1) from the J 45873 on to the each cylinder head return port.
10. Install the J 23738-A onto each black hose and apply 15 inches Hg of vacuum to each port and record if each side holds vacuum.
11. Perform the lower valve cover removal procedure for the bank(s) that did not hold vacuum. Then go to step 12.
12. Connect the fuel return lines on both cylinder heads.

NOTE: Refer to Fastener Notice in Service Precautions.

IMPORTANT: When the fuel injector pressure lines are removed, debris will fall into the fuel injector inlet fitting. Vacuum the debris from the inlet fitting of the fuel injector before reconnecting fuel lines to the fuel injectors.

Tighten
Tighten the bolts to 15 N.m (11 lb ft).




13. Install the J 42964-1 3/8 Fuel Pipe Shutoff Valve (2) to the fuel return line (1).
14. Install the J 35800-A Fuel Injector Cleaner on the J 42964-1 3/8 Fuel Pipe Shutoff Valve port closest to the fuel return line.
15. Ensure that the shutoff valve is closed.
16. Add 10 ounces of diesel fuel and 4 ounces of oil dye to the J 35800-A.
17. Connect the shop air supply to the J 35800-A.
18. Adjust the pressure regulator on the J 35800-A to 15 psi.
19. Clean the fuel injectors and fuel return lines with brake cleaning solvent and let dry.
20. Open the valve on the bottom of the J 35800-A canister.
21. Inspect for leaks around the fuel injectors and the spill lines with a J 28428-E High Intensity Black Light Kit. Then go to step 29.
22. Remove both upper valve covers.
23. Remove the engine oil fill tube on the front engine cover.
24. Install the fuel injector feed pipes.

IMPORTANT: When the fuel injector pressure lines are removed, debris will fall into the fuel injector inlet fitting. Vacuum the debris from the inlet fitting of the fuel injector before reconnecting fuel lines to the fuel injectors.

Tighten
Tighten the fuel feed pipes to 44 N.m (32 lb ft).

25. Add 8 ounces of oil dye to the fuel tank. On dual tank systems add the dye to the front, or primary, tank. Refer to Fuel System Description.
26. Start the engine.

IMPORTANT: During this test the fuel dye may quickly dilute in the engine oil. Observe the internal fuel components for dye traces immediately after startup.

27. Increase the fuel pressure to 160 MPa with a scan tool.
28. Inspect for leaks around the fuel injectors and the fuel injection pump drive gear with a J 28428-E. Then go to step 29.
29. Tighten or replace any leaking components or gaskets.
30. Perform the lower valve cover installation procedures as necessary.
31. Retest the system for engine oil dilution by performing the following procedure:
31.1. Drain the engine oil from the crankcase and refill.
31.2. Run the engine at idle for 10 minutes.
31.3. Stop the engine and wait 10 minutes, then check the oil level on the Dip Stick. This will be the initial oil level.
31.4. Run the engine at idle for 5 minutes while commanding the fuel pressure to 160 MPa with a scan tool.
31.5. Stop the engine and wait 10 minutes, then check the oil level on the Dip Stick.
- If the engine oil level is not more than 3/16 inch above the initial oil level, the system is OK.
- If the engine oil level is more than 3/16 inch above the initial oil level, go to step 31.F.
31.6. Run the engine at idle again for 5 minutes while commanding the fuel pressure to 160 MPa with a scan tool.
31.7. Stop the engine and wait 10 minutes, then check the oil level on the Dip Stick.
- If the engine oil level is not more than 3/16 inch above the last oil level, the system is OK.
- If the engine oil level is more than 3/16 inch above the last oil level, go back to step 1.