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Fuel Leaks Inside Of Engine (6.6L)

NOTE: For component locations, see COMPONENT LOCATIONS .
NOTE: If directed here from FUEL RETURN SYSTEM DIAGNOSIS, go to step  15. Step 15)  will be performed with same components disconnected as stated in that test.
  1. Disconnect fuel return line at engine. See QUICK CONNECT FITTINGS (METAL COLLAR) under FUEL SYSTEMS in appropriate REMOVAL, OVERHAUL & INSTALLATION article.
  2. Remove air duct from air cleaner assembly to turbo inlet.
  3. Remove air intake pipe.
  4. Remove fuel return rubber hose of fuel injection pump from junction block. Cap fitting on block with a 3/8 inch rubber cap to prevent fuel leakage.
  5. Install Vacuum Pump (J 23738-A) at fuel return pipe.
  6. Apply 15 in. Hg of vacuum to pipe. If vacuum holds, reinstall disconnected components and go to step  22. If vacuum does not hold, go to next step.
  7. Remove generator. See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.
  8. Disconnect fuel return line from right front cylinder head.
  9. Install Black hose from (J 45873) onto each cylinder head return port.
  10. Install (J 23738-A) onto each Black hose and apply 15 in. Hg of vacuum to each port and record if each side holds vacuum.
  11. Perform lower valve cover removal procedure for bank(s) that did not hold vacuum. Then go to next step.
    12. NOTE: When fuel injector pressure lines are removed, debris will fall into fuel injector inlet fitting. Vacuum debris from inlet fitting of fuel injector before reconnecting fuel lines to fuel injectors.
  12. Connect fuel return lines on both cylinder heads. Tighten bolts to specification. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.
  13. Install 3/8" Fuel Pipe Shutoff Valve (J 42964-1) to fuel return line.
  14. Install Fuel Injector Cleaner (J 35800-A) on 3/8" Fuel Pipe Shutoff Valve (J 42964-1) port closest to fuel return line.
  15. Ensure shutoff valve is closed.
  16. Add 10 ounces of diesel fuel and 4 ounces of oil dye to (J 35800-A).
  17. Connect shop air supply to (J 35800-A).
  18. Adjust pressure regulator on (J 35800-A) to 15 psi.
  19. Clean fuel injectors and fuel return lines with brake cleaning solvent and let dry.
  20. Open valve on bottom of (J 35800-A) canister.
  21. Inspect for leaks around fuel injectors and spill lines with High Intensity Black Light Kit (J 28428-E). Then go to step  29.
  22. Remove both upper valve covers. See 6.6L V8 DIESEL article in ENGINES.
  23. Remove engine oil fill tube on front engine cover.
    24. NOTE: When fuel injector pressure lines are removed, debris will fall into fuel injector inlet fitting. Vacuum debris from inlet fitting of fuel injector before reconnecting fuel lines to fuel injectors.
  24. Install fuel injector feed pipes. Tighten fuel feed pipes to specification. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.
  25. Add 8 ounces of oil dye to fuel tank. On dual tank systems add dye to front, or primary, tank.
    26. NOTE: During this test, fuel dye may quickly dilute in engine oil. Observe internal fuel components for dye traces immediately after start up.
  26. Start engine.
  27. Increase fuel pressure to 23,206 psi (160 MPa) with scan tool.
  28. Inspect for leaks around fuel injectors and fuel injection pump drive gear with (J 28428-E). Then go to next step.
  29. Tighten or replace any leaking components or gaskets.
  30. Perform lower valve cover installation procedures as necessary. See 6.6L V8 DIESEL article in ENGINES.
  31. Retest system for engine oil dilution by performing the following procedure:
    1. Drain engine oil from crankcase and refill.
    2. Run engine at idle for 10 minutes.
    3. Stop engine and wait 10 minutes, then check oil level on dipstick. This will be "Initial" oil level.
    4. Run engine at idle for 5 minutes while commanding fuel pressure to 23,206 psi (160 MPa) with scan tool.
    5. Stop engine and wait 10 minutes, then check oil level on dipstick. If engine oil level is not more than 3/16" above "Initial" oil level, system is okay. If engine oil level is more than 3/16" above "Initial" oil level, go to next step in this procedure.
    6. Run engine at idle again for 5 minutes while commanding fuel pressure to 23,206 psi (160 MPa) with scan tool.
    7. Stop engine and wait 10 minutes, then check oil level on dipstick. If engine oil level is not more than 3/16" above last oil level checked, system is okay. If engine oil level is more than 3/16" above last oil level checked, condition still exists. Go back to step  1.
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