GMC C Series 1993, Repair Manual

Page: 135 / 264

51-6 AIR FOUNDATION BRAKES
Inspect
• The diaphragm and return spring for wear.
• The inside of the brake chamber for corrosion.
Replace if corroded.
• The pushrod assembly for damaged threads.
0
Install or Connect (Figure 12)
1. Return spring (23) into the housing assembly (22).
2. Pushrod assembly (21).
• Compress the return spring and clamp it in place
with locking pliers.
3. Diaphragm (25).
4. Pressure cap (26).
5. Clamp assembly (24).
• Align the marks made during disassembly.
N O T IC E : S e e “N o tic e " o n p a g e 51-1.
6. Bolts (27) and nuts (28).
Tighten
• Nuts (28) to 34 N-m (25 ft. lbs.).
7. Release the locking pliers.
j
Figure 12—Standard Brake Chamber
SPUING
BRAKE CHAMBERS
Brake chamber identifying information is stamped on
the cover of the chamber. The emergency side Of the
Anchorlok Gold Seal spring brake chamber uses a
crimped safety seal and is not serviceable.
A N C H O R LO K (GOLD SEAL
TY P E )
CAGING (Figures 14, 15, and 16)
CAUTION: Before attempting brake chamber
removal, block the vehicle’s wheels securely
since the parking brake will not be applied;
Do not remove the chamber from the vehicle
before caging the power spring. Do not
remove the outer chamber clamp. Failure to
follow this caution can result in persona!
injury.
1. Blbck the vehicle wheels.
2. Remove the caging release fool from the pocket on
the adapter (figure 14).
3. Remove the spring housing rubber cap and insert
theitool in the hole and turn 1/4 turn (figure 14).
4. Pull on the release tool to seat the release stud
cross pin in the cross pin area of the pressure
plate. 1
5. Assemble the release tool washer and nut on the
release tool finger tight (figure 15).
Tighten (Figure 16)
Nut to 41 N-m (30 ft. lbs.).
6. The dimension “X" should be a minimum of 76 mm
(3 inches) (figure 16).