Cylinder Head Leak Test - Navistar International DT 466 Diagnostic/Troubleshooting Manual

112

Cylinder Head Leak Test

1. Remove the valve cover following the procedure
in the Engine Service Manual.
Figure 127 Cylinder head (top) cup plugs
Figure 128 Cylinder head (intake side) cup plugs
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
4 ENGINE SYMPTOMS DIAGNOSTICS
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
2. Pressurize the cooling system to 96 kPa (14 psi)
3. Inspect the entire cylinder head for cracks or leaks
at the cup plugs.
• If a leak is noticed, repair or replace.
• If no leaks are noticed, do step 4.
4. Drain coolant from system.
5. Remove cylinder head from engine following the
procedures in the Engine Service Manual.
6. Inspect and pressure test the cylinder head
following the procedures in the Engine Service
Manual.
• Inspect cylinder head gasket for damage at
sealing points that may have caused a leak.
Verify crankcase and cylinder head surface
flatness using a straightedge and feeler
gauge. Replace the head gasket. Repair or
replace the cylinder head if necessary.
• Inspect the cylinder head for cracks in the
coolant passages. Repair or replace.
7. If cylinder head is in good condition, remove
cylinder sleeve crevice seals following the
procedures in the Engine Service Manual.
• Inspect the engine block for cracks in the
coolant passages. Repair or replace.
• Inspect for damaged cylinder liners and seals.
Repair or replace.
8. Test the cooling system again after any repair to
validate the repair.