1983-84 With 6.9L Diesel and 7.5L (460cu. in.) Gas Engines
1985-86 All With Manual Transmission
See Figure 1
The hydraulic clutch system operates much like a hydraulic brake system. When you push down (disengage) the clutch pedal, the mechanical clutch pedal movement is converted into hydraulic fluid movement, which is then converted back into mechanical movement by the slave cylinder to actuate the clutch release lever.
The system consists of a combination clutch fluid reservoir/master cylinder assembly, a slave cylinder mounted on the bellhousing, and connecting tubing.
Fluid level is checked at the master cylinder reservoir. The hydraulic clutch system continually remains in adjustment, like a hydraulic disc brake system, so not clutch linkage or pedal adjustment is necessary.
See Figure 2
The clutch hydraulic system is serviced as a complete assembly and is pre-filled and bled. Individual components are not available.
- From inside the truck cab, remove the cotter pin retaining the clutch master cylinder pushrod to the clutch pedal lever. Disconnect the pushrod and remove the bushing.
- Remove the two nuts retaining the clutch reservoir and master cylinder assembly to the firewall.
- From the engine compartment, remove the clutch reservoir and master cylinder assembly from the firewall. Note here how the clutch tubing routes to the slave cylinder.
- Push the release lever forward to compress the slave cylinder.
- On all engines except the diesel and the 7.5L gasoline engines, remove the plastic clip that retains the slave cylinder to the bracket. Remove the slave cylinder.
- On the diesel and the 7.5L, the steel retaining clip is permanently attached to the slave cylinder. Remove the slave cylinder by prying on the clip to free the tangs while pulling the cylinder clear.
- Remove the release lever by pulling it outward.
- Remove the clutch hydraulic system from the truck.
- Position the clutch pedal reservoir and master cylinder assembly into the firewall from inside the cab, and install the two nuts and tighten.
- Route the clutch tubing and slave cylinder to the bell housing, taking care that the nylon lines are kept away from any hot exhaust system components.
- Install the slave cylinder by pushing the slave cylinder pushrod into the cylinder. Engage the pushrod into the release lever and slide the slave cylinder into the bell housing lugs. Seat the cylinder into the recess in the lugs.
- Clean the master cylinder pushrod bearing and apply a light film of SAE 30 engine oil.
- From inside the cab, install the bushing on the clutch pedal lever. Connect the clutch master cylinder pushrod to the clutch pedal lever and install the cotter pin.
- Check the clutch reservoir and add fluid if required. Depress the clutch pedal at least ten times to verify smooth operation and proper clutch release.