Repair and Diagnosis: Transmission: Clutches: Description

The hydraulic clutch consists of a clutch plate, pressure plate and pilot bearing. Hydraulic clutch has a master cylinder with a reservoir. Clutch pedal moves master cylinder push rod, and a slave (actuator) cylinder at bellhousing moves clutch fork and release bearing. See Fig 1 .

Hydraulic clutch system provides automatic clutch adjustment. No adjustment of clutch linkage or pedal position is required.

Fig 1: Exploded View Of Clutch Assembly & Pilot Bearing (Typical)

Courtesy of GENERAL MOTORS CORP.

The hydraulic line joining master cylinder to actuator cylinder has a coupling located near left rear of engine. This coupling contains internal check valves that allow master cylinder half of system to be disconnected from actuator half without loss of fluid. The coupling can be reconnected and no bleeding is required. service replacement master and actuator cylinder components are furnished pre-filled with fluid. See Fig 2 .

No service is possible to individual components of master cylinder assembly or actuator cylinder assembly. Complete cylinder units must be installed when servicing hydraulic clutch.

Fig 2: Identifying Commercial Van Clutch Hydraulic System

Courtesy of GENERAL MOTORS CORP.