The clutch driven disc contains asbestos, which has been determined to be a cancer causing agent. Never clean clutch surfaces with compressed air. Avoid inhaling any dust from any clutch surface. When cleaning clutch surfaces, use a commercially available brake cleaning fluid.
REMOVAL & INSTALLATION
See Figures 1, 2 and 3
- Raise the front of the truck and support it on jackstands.
- Remove the tension spring on the clutch fork.
- Remove the hydraulic line from the release cylinder. Be careful not to damage the fitting.
- Turn the release cylinder pushrod in sufficiently to gain clearance from the fork.
- Remove the mounting bolts and withdraw the cylinder.
- Install the hydraulic line from the master cylinder.
- Position the cylinder on the clutch housing and install the clamp and retaining screws. Tighten the attaching bolts to 18-25 ft. lbs. (25-35 Nm) on 1970-79 models and 22-30 ft. lbs. (30-40 Nm) on 1980-88 models.
- Adjust the fork tip clearance to 0.079 in. (2mm) on 1970-71 models
The system must be bled after the cylinder is reinstalled.
See Figure 4
- Remove the pushrod, rubber boot, piston and cups from the cylinder.
- Clean the inside of the cylinder with a rag and inspect for scoring. If there is no serious damage, hone the cylinder just enough to remove deposits. Replace the cylinder if light honing does not remove the score marks. Wash all the parts in brake fluid before assembly.
- Coat the new rubber parts in brake fluid and reassemble. Coat the piston with lithium soap based glycol grease.