What causes rear drum brakes to lock up?
Rear drum brakes can lock for several reasons. One reason could be a defective wheel cylinder, which is part of the brake system. Your parking brake cable could also be adjusted too tight. The slightest pressure on the brake pedal, will then cause the brakes to work at full force, causing the lock up.
What is a brake shoe adjuster?
– Brake shoe adjusters maintain correct drum-to-lining clearance, as the brake linings wear. This lengthens the adjusting mechanism, and the linings are moved closer to the brake drum, thereby maintaining the correct lining-to-drum clearance.
How do you know when your drum brakes need to be replaced?
Technical Bulletins
- Inconsistent brake pedal feel. If the rear brakes are drum brakes, the driver may feel vibrations under braking.
- Hand brake feels loose. If the hand brake requires a hard yank to keep the car from rolling off, chances are the brake shoes need replacing.
- Scraping noise while braking.
How do you adjust the self adjuster on a drum?
The process was to tighten the adjuster or eccentric adjusting cam to a point where the shoes contact the drum friction surface and backing off the adjuster or eccentric adjusting cam to where the shoes just cleared the drum. It’s all in the “feel” as you turn the wheel and move the adjuster or eccentric cam.
Where is the adjuster screw on a brake drum?
Turn the brake drum so that the access hole is aligned with the drum’s adjuster screw. The adjuster screw is large and slotted, and is located beneath just beneath the centerline that runs horizontally across the back of the drum. Turn the adjuster screw counterclockwise until it comes to a halt.
How do you remove a drum from a star wheel?
While holding back the lever, use another screwdriver to turn the star wheel counter-clockwise until it completely stops. This retracts the brake shoes so the drum should be free to remove. Be sure to remove the retaining screws if the drum will turn but won’t come off the wheel studs; these screws usually require a flathead screwdriver.
What should I do if my drum brake is stuck?
Observe the brake operation while an assistant sets and releases the parking brake. Note that the parking brake will not actually set with the drum released, so take care not to move the parking brake lever or pedal too far. The rear brake shoe should move out when the parking brake is set, and move back when the parking brake is released.