MANIFOLD 7N6445 - Caterpillar

Probable Causes
Leaks
Cylinder head gasket
Cylinder headRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Determine which Cylinder is Leaking
A. Pressurize each cylinder. Refer to the Special Instruction, REHS7138, "New Cylinder Head and Head Gasket Leak Test Procedure Available for 3500 Engines" for additional information.
Leaks
Result: A leaking cylinder is not found.
Proceed to Test Step 2.
Result: A leaking cylinder is found.
Repair: Repair or replace damaged components. Refer to the Disassembly and Assembly manual for additional information.
If the problem is not resolved, proceed to Test Step 2.
2. Inspect the Cylinder Head Gasket
A. Remove the cylinder head. Refer to the Disassembly and Assembly manual for additional information.
B. Check the cylinder liner projection. Refer to Testing and Adjusting, "Cylinder Liner Projection" for additional information.
Cylinder Head Gasket
Result: The cylinder head gasket and water seals are not leaking.
Proceed to Test Step 3.
Result: The cylinder head gasket and/or water seals are leaking.
Repair: Install a new cylinder head gasket and new water seals in the spacer plate. Refer to the Disassembly and Assembly manual for additional information.
Proceed to Test Step 3.
3. Inspect the Cylinder Head
A. Check for cracks in the cylinder head.
B. Perform a leak test on the cylinder head. Refer to the Testing and Adjusting manual for additional information.
Cylinder Head
Result: A crack is found in the cylinder head.
Repair: Repair or replace the cylinder head. Refer to the Disassembly and Assembly manual for additional information.
Verify that the repair eliminated the problem.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).