7.
Using a valve spring compressor, remove valve
stem keys, caps, springs, and oil seals. Discard
oil seals. Organize springs so they can be in-
stalled in their original positions. Repeat for
other each cylinder.
Cylinder Leak Down Test
NOTE: Rotate crankshaft to place piston in cylin-
der being tested at top dead center (TDC) of the
compression stroke, with both valves closed. Lock
crankshaft balancer in place to prevent piston
movement.
1.
Install the J 35667-A Cylinder Head Leakdown
Tester (Hyster P/N 4060759) tester in the spark
plug port on cylinder to be tested.
2.
Apply shop air pressure to J 35667-A Cylinder
Head Leakdown Tester (Hyster P/N 4060759)
tester and adjust according to manufactures in-
structions.
3.
Record cylinder leakage value. Cylinder leak-
age exceeding 25 percent is considered exces-
sive and may require component service.
Air leakage from intake or exhaust system may
indicate a worn or burnt valve or a broken valve
spring.
• Ensure that both valves are closed.
• Inspect cylinder head for a broken valve
spring.
• Remove and inspect suspect cylinder head.
See Cylinder Head Repair, Remove and
Disassemble.
Air leakage from crankcase, oil level indicator, or
oil fill tube may indicate worn piston rings, a
damaged piston, a worn or scored cylinder bore,
a damaged engine block or a damage cylinder
head.
• Remove piston from the suspect cylinder.
See Piston and Connecting Rod Assem-
blies, Remove.
• Inspect piston and connecting rod assem-
bly. See Piston, Clean and Inspect.
• Inspect engine block. See Engine Block,
Clean and Inspect.
• Inspect cylinder head. See Cylinder Head
Repair, Clean and Inspect.
Air bubbles in cooling system may indicate a
damaged cylinder head or a damaged cylinder
head gasket.
• Remove both cylinder heads. See Cylinder
Head Repair, Remove and Disassemble.
• Inspect engine block. See Engine Block,
Clean and Inspect.
• Inspect cylinder head. See Cylinder Head
Repair, Clean and Inspect.
Clean and Inspect
WARNING
Cleaning solvents can be flammable and toxic and
can cause skin irritation. When using cleaning
solvents, always follow the solvent manufac-
turer’s recommended safety procedures.
WARNING
Compressed air can move particles so they cause
injury to the user or to other personnel. Make sure
the path of the compressed air is away from all
personnel. Wear protective goggles or a face
shield to prevent injury to the eyes.
1.
Using cleaning solvent, clean the following
items:
• Valve stem keys
• Valve spring cap
• Valve spring
2.
When cleaning is complete, dry components
with compressed air. See Figure 9.
0600 SRM 1251 Cylinder Head Repair
7
To Next Page
Loading...
