See Figures 1, 2, 3, 4, 5 and 6
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 bell housing, 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.
REMOVAL & INSTALLATION
There are 2 types of slave cylinders used: an internally mounted (in the bell housing) and an externally mounted type.
- From inside the vehicle, pry the pushrod and retainer bushing from the cross shaft lever pin.
- Disconnect the interlock switch connector plug.
- Remove the 2 retaining nuts and support bracket connecting the clutch reservoir and master cylinder assembly to the firewall.
- From the engine compartment, first note the clutch tube routing to the slave cylinder, then remove the attaching hardware for the hydraulic tube retaining clips.
- From the engine compartment, remove the clutch reservoir and master cylinder assembly from the firewall. On F-Series and Bronco, when the master cylinder studs are free of the dash panel, rotate cylinder counterclockwise about 100 degrees to clear the interlock switch and remove the cylinder from the vehicle.
- On 7.3L diesel and 7.5L gas engine vehicles, use a suitable prytool and lift the 2 retaining tabs of the slave cylinder retaining bracket. Disengage the tabs from the bell housing lugs and then slide outward and remove.
- On 4.9L, 5.0 and 5.8L engine vehicles, depress the release ring on the tube quick disconnect and gently pull the connector free of the concentric slave cylinder fitting.
- Remove the clutch hydraulic system from the vehicle.
- Position the clutch fluid reservoir and master cylinder assembly into the firewall from inside the cab install the 2 nuts.
- Correctly route the hydraulic tubing and sleeve cylinder to the transmission bell housing.
Care must be taken during routing of the nylon line to keep away from the engine exhaust system.
- Reinstall the clutch tube retaining clips.
Before installing external type slave cylinders, perform the clutch system bleeding procedure.
- On 7.3L diesel and 7.5L gas engine vehicles, 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.
- On 4.9L, 5.0 and 5.8L engine vehicles, push the tube quick disconnect back onto the concentric slave cylinder fitting.
When installing a new hydraulic system, the external slave cylinder used on 7.3L diesel and 7.5L gas engine vehicles, contains a shipping strap that pre-positions the pushrod for installation and also provides a bearing insert. When installation of the slave cylinder is completed, the first actuation of the clutch pedal will beak the shipping strap and give normal system operation.Concentric Slave Cylinder
See Figures 7 and 8
This type slave cylinder is internally located inside the bell housing on the transmission input shaft. Removal of the transmission is required in order to replace it.
- Disconnect the negative battery cable.
- Disconnect the fluid coupling at the transmission, using the clutch coupling removal tool T88T-70522-A or equivalent. Slide the white plastic sleeve toward the slave cylinder while applying a slight tug on the tube.
If the special coupling tool is not available, the fluid coupling can be uncoupled by using a flat-bladed tool. Carefully pressing in around the coupling while applying a slight tug on the tube.
- Remove the transmission assembly.
- Remove the slave cylinder-to-transmission retaining bolts.
- Remove the slave cylinder from the transmission input shaft.
- Fit the slave cylinder over the transmission input shaft with the bleed screws and coupling facing the left side of the transmission.
- Install the slave cylinder retaining bolts. Tighten to 14-19 ft. lbs. (19-26 Nm).
- Install the transmission.
- Connect the coupling to the slave cylinder.
- Properly bleed the hydraulic system.
- Connect the negative battery cable.
HYDRAULIC SYSTEM BLEEDING
Externally Mounted Slave Cylinder
- Clean the reservoir cap and the slave cylinder connection.
- Remove the slave cylinder from the housing.
- Using a 3 / 32 in. punch, drive out the pin that holds the tube in place.
- Remove the tube from the slave cylinder and place the end of the tube in a container.
- Hold the slave cylinder so that the connector port is at the highest point, by tipping it about 30° from horizontal. Fill the cylinder with DOT 3 brake fluid through the port. It may be necessary to rock the cylinder or slightly depress the pushrod to expel all the air.
- When all air is expelled (no more bubble are seen), install the slave cylinder.
Some fluid will be expelled during installation as the pushrod is depressed.
- Remove the reservoir cap. Some fluid will run out of the tube end into the container. Pour fluid into the reservoir until a steady stream of fluid runs out of the tube and the reservoir is filled. Quickly install the diaphragm and cap. The flow should stop.
- Connect the tube and install the pin. Check the fluid level.
- Check the clutch operation.
See Figure 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19
With the quick-disconnect coupling, no air should enter the system when the coupling is disconnected. However, if air should somehow enter the system, it must be bled.
- Remove the reservoir cap and diaphragm. Fill the reservoir with DOT 3 brake fluid.
- Connect a piece of rubber tubing to the slave cylinder bleed screw. Place the other end in a container.
- Loosen the bleed screw. Gravity will force fluid from the master cylinder to flow down to the slave cylinder, forcing air out of the bleed screw. When a steady stream with no bubbles flows out, the system is bled. Close the bleed screw.
Check periodically to make sure the master cylinder reservoir doesn't run dry.
- Add fluid to fill the master cylinder reservoir.
- Fully depress the clutch pedal. Release it as quickly as possible. Pause for 2 seconds. Repeat this procedure 10 times.
- Check the fluid level. Refill it if necessary. It should be kept full.
- Repeat Steps 5 and 6 five more times.
- Install the diaphragm and cap.
- Have an assistant hold the pedal to the floor while you crack the bleed screw (not too far-just far enough to expel any trapped air). Close the bleed screw, then release the pedal.
- Check, and if necessary, fill the reservoir.