GMC C Series 1993, Repair Manual

Page: 125 / 264

5H-20 AIR BRAKE VALVES
screws: . ,
16. Four cover screws (1), washers, and Cover (2).
17. Outer piston spring (3).
18. Inner piston spring (4).
19. Piston (5) and O-rings (6 and 7).
20. Spring (31).
21. Piston (30) and O-rings (29 and 28).
Clean
• All metal parts in mineral spirits or another suitable
solvent.
| y | - Inspect
• All parts for wear or cracks. Replace as needed.
• Valve seals for nicks or burrs. Replace as needed.
+ + I Install or Connect (Figure 24)
N O T IC E : F o r s te p s 8 a n d 12, s e e “N o tic e " o n
p a g e 5 H -1 .
1. Lubricate seals, piston bores, and metal to metal = ,
moving surfaces with Delco Silicone Lube (GM P/N
18010909 or equivalent).
• Use only new rubber seals from the repair kit. :
2. Piston (30) and O-rings (29 and 28).
3. Spring (31).
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; 4. Piston (5) and O-rings (6 and 7).
: 5. Inner piston spring (4).
6. Outer piston spring (3).
7. Cover (2).
8. Four cover screws (1) and washers.
Q Tighten
• ♦ Screws (1) to 7.3 N-m (65 in. lbs.).
9. Valve disc (26).
10. Springs (25).
11. Stop (24),
12. Cap (22) and O-ring (23).
^ Tighten
• Cap (22) to 14 N.m (120 in. lbs.).
13. Inlet and exhaust valve assembly (32).
14. Valve retainer (13).
15. Valve spring (14).
16. Outer 0-ring (16) and inner O-ring (15) in seal’
retainer (17).
17. Retainer ring (18).
18. Valve assembly (32) in body (27),
19. Exhaust Valve (19).
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20. Screws. (20).
21. Check valve (11).
22. Guide (10).
23. Spring (9),
24. Hex socket plug (8).
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