DORMAN CM116209 Clutch Master Cylinder Instruction Manual
- June 1, 2024
- DORMAN
Table of Contents
DORMAN CM116209 Clutch Master Cylinder
Specifications
- Product Name: Clutch Master Cylinder
- Manufacturer: GM
- Model: 1993-88 C and K Pickups
- Material: Plastic or Sheet Metal
Identifying Clutch Master Cylinder Failure
The clutch master cylinder housing can fracture or have blown out seals due to excessive hydraulic pressure build-up. Fractures in plastic units may start as small cracks leading to leaks and visible cracks, while seals in sheet metal units can blow out.
Possible Causes of Failure
- A binding clutch fork/ball stud
- A restricted line to the slave cylinder
- An incorrect clutch/pressure plate requiring greater force
STOP – Important Notice
Clutch Master Cylinder Failure
The clutch master cylinder housing can fracture, or seals can be blown out due to excessive hydraulic pressure build up (Fig. 1). Fractures in plastic units can begin as a small crack creating a leak, which can later develop into a visible crack in the clutch master cylinder housing. Also, for those units made of sheet metal, seals will blow out due to the same high pressure build up. This is often mistakenly diagnosed as a defective master cylinder, especially after repeated failures.
The various possible causes for this problem are:
- A binding clutch fork / ball stud
- A restricted line to the slave cylinder
- An incorrect clutch / pressure plate requiring a greater force to be exerted.
The most common cause of master cylinder fracture has been reported to be a
binding clutch fork, or throw out lever (Fig. 2). If the area of contact
between the ball stud and the clutch fork is binding, from lack of
lubrication, hydraulic pressure in the clutch system can rise substantially.
Excessively high pressure can cause the master cylinder to fracture.
If there is a squeaking in the clutch fork or increased pedal resistance the
ball stud and clutch fork should be inspected and lubricated, or replaced.
IMPORTANT: Grease should be added
“SPARINGLY” to the grease zerk/fitting located on the transmission casing
(Fig. 3). Excessive grease can contaminate the clutch disc friction surfaces
resulting in slip or chatter and the need to replace the disc. The grease
zerk/fitting may not be readily visible on high mileage vehicles and may
require cleaning away of road dirt to make the fitting visible and
serviceable. Lubricate grease zerk/fitting at 30,000-mile intervals with a
hand-operated grease gun only. DO NOT LUBRICATE MORE OFTEN.
Finally, visually inspect the line from the clutch master cylinder to the
slave cylinder for any kinks or other d amage, which could cause a hydraulic
restriction.
