Wheel Cylinder: Service and Repair

Fig. 8 Disassembled View Of Wheel Cylinder (typical):

1. Raise and support vehicle.
2. Remove wheel, drum and brake shoes.
3. Disconnect hydraulic line at wheel cylinder. Do not pull metal line away from cylinder, as this may kink or bend line. Line will separate from cylinder when cylinder is moved away from brake backing plate.
4. Remove wheel cylinder-to-brake plate attaching screws, then the wheel cylinder.
5. Remove boots, pistons, springs and cups from cylinder, Fig. 8.
6. Clean all parts with brake fluid.
7. Inspect cylinder bore. A scored bore may be honed as long as the diameter is not increased by more than .005 inch. Replace worn or damaged parts as necessary.
8. Ensure hands are clean before proceeding with assembly. Lubricate cylinder wall and rubber cups with brake fluid, then install springs, cups, pistons and boots in housing.
9. Wipe end of hydraulic line to remove any foreign matter, then place wheel cylinder in position. Enter tubing into cylinder and start threads on fitting.
10. Secure cylinder to backing plate, then complete tightening of tubing fitting.
11. Install brake shoes, drum and wheel.
12. Bleed system as outlined previously, then adjust brakes.