GMC 1990 Light Truck Repair Manual page 394

6A1-20 2.5 LITER L4 ENGINE
18. Intake Valve
19. Exhaust Valve
28. Valve Spring Cap
29. Valve Stem Oil Seal
30. Valve Keepers
34. Valve Stem Oil Shield
35. Valve Spring (with damper)
36. Valve Stem Seal
Figure 34—Valves and Components
Disassemble (Figures 34 and 35)
Tool Required:
J 8062 Valve Spring Compressor
1. Valve keepers (30).
• Compress the valve spring using J 8062.
• Remove the valve keepers.
• Remove the tool.
2. Cap (28).
3. Valve spring (35) and shield (34).
4. Valve stem oil seals (29).
5. Valves (18 and 19). Place them in a rack so they can
be returned to their original position at assembly.
6. Valve stem seal (36).
For information on cylinder head measuring and
re c o n d itio n in g , refer
MECHANICAL (SEC. 6A) in this manual.
*
Assemble (Figures 34, 35 and 36)
Tools Required:
J 8062 Valve Spring Compressor
J 22330 Valve Stem Seal Checker
and Tester
1. New valve stem seals (36).
• Lubricate the seal in order to aid in assembly.
2. Valves (18 and 19).
• Lubricate the valve stems with engine oil.
• Insert the valves into the proper ports.
3. Valve spring (35) and shield (34).
4. Cap (28).
5. Valve keepers (30).
F-04484
to GENERAL ENGINE
Figure 35—Compressing the Valve Springs
• Compress the valve springs using J 8062.
Compress the spring enough so the lower
valve stem groove can be clearly seen.
• Push a new valve stem oil seal (29) onto the
valve stem. The seal is to be installed on the
lower groove of the stem. Make sure the seal
is flat and not twisted.
• Apply grease to the area of the upper valve
stem groove. Assemble the two valve keepers,
using the grease to hold the keepers in place.