Valve Stem Seal And Valve Spring Replacement - GMC G Service Manual

VALVE STEM SEAL AND VALVE
SPRING REPLACEMENT
Remove or Disconnect (Figures 5 and 6)
B
Tools Required:
J 23590 Air Adapter
J 5892-B Spring Compressor
1. Rocker arm cover. Refer to "Rocker Arm Cover
Replacement" in this section.
Rocker arms. Refer to "Rocker Arm and Pushrod
2 .
Replacement" in this section.
3. Spark plugs.
4. Valve keepers (20).
• Install J 23590 into the spark plug hole.
• Apply compressed air to hold the valves in
place.
• Install a rocker arm nut (figure 6).
• Use J 5892-B to compress the valve spring
(figure 6).
• Remove the valve keepers.
• Carefully release the spring tension. Remove
J 5892-B.
5. Cap (21) and/or rotator (28), shield (22) and spring
(26) with damper (25).
6. O-ring seal (23), and seal (24) (intake valve only).
K H Install or Connect (Figures 5, 6 and 7)
Tools Required:
J 23590 Air Adapter
J 5892-B Spring Compressor
J 23738-A Vacuum Pump
20. Valve Keeper
21. Cap
22. Shield
23. O-Ring Seal
24. Seal
25. Damper
Figure 5 — Valves and Components
26.
27.
28.
29.
4.3 LITER V6 6A3-7
1. New seal (24) (intake valve only). Install the seal over
the intake valve stem and seat it against the head.
2. Spring (26) with damper (25), shield (22) and cap (21)
and/or rotator (28).
3. New O-ring seal (23) and valve keepers (20).
• With air pressure applied to the cylinder with
J 23590, compress the spring with J 5892-B
(figure 6).
• Lubricate the O-ring seal with engine oil. Install
the seal on the valve stem. Make sure the seal
is not twisted.
• Install the valve keepers. Use grease to hold
them in place.
• Carefully release spring pressure. Make sure
the valve keepers stay in place.
• Remove J 5892-B and J 23590.
• Check each O-ring seal for leakage (figure 7).
• Place the suction cup furnished with
J 23738-A over the shield.
• Connect J 23738-A to the suction cup and
apply vacuum. Watch the vacuum pump
gage. No air should be able to leak past
the seal. If the seal will not hold vacuum, it
may have been damaged or improperly
installed.
4. Spark plugs.
5. Rocker arms. Refer to "Rocker Arm and Pushrod
Replacement" in this section.
\ ^ \ Adjust
• Valves. Refer to "Valve Adjustment" in this
section.
6. Rocker arm cover. Refer to "Rocker Arm Cover
Replacement" in this section.