All disc brakes are inherently self-adjusting. No periodic adjustment is either necessary or possible.
See Figure 11970-74
The front wheels are equipped with two wheel cylinders and two sets of adjusters. Each brake shoe must be adjusted separately to achieve the correct adjustment. The procedure outlined is for the adjustment of one shoe; repeat the procedure on all four shoes of the front wheel brakes.
- Raise the front of the truck and support the crossmember with jackstands.
- Remove the adjusting hole plug from the backing plate.
- Expand the brake shoe with a starwheel adjusting wrench or a screwdriver. Pump the brake pedal several times while doing this to center the brake shoe.
- Back off the adjuster just enough so that the wheel will turn with a slight drag. Then back off the adjuster another five notches. The wheel should turn smoothly.
- If the wheel does not turn smoothly, back off one or two more notches. If the wheel is still dragging, check for worn or defective parts.
- Pump the brake pedal again to center the shoe.
- Proceed to the next shoe and repeat the procedure.
See Figures 2, 3 and 4
1975-88 Toyota trucks utilize self-adjusting brakes. The following procedure is necessary only after the brake shoes have been changed.
- Place blocks under the front wheels so that the truck will not roll forward when it is jacked up at the rear.
- Fully release the emergency brake.
- Raise the rear of the truck and support the differential housing with jackstands.
- Remove the plug from the adjusting hole at the bottom of the backing plate.
Unlike the front wheels, the rear brakes have only one wheel cylinder and therefore both shoes on the wheel are adjusted at the same time.
- Turn the adjusting starwheel to expand the shoes fully. While doing this, have a friend step on the brake pedal occasionally to center the shoes.
- Tighten the shoes until the wheel will not turn when you release the brake pedal.
- From this position back off the adjuster until the wheel turns with just a slight drag.
- Back off the adjuster an additional five notches. The wheel should turn smoothly. If it does not, back off another two or three notches. Should this fail, check for worn or defective parts.
- Adjust the other wheel in the same manner.
See Figure 5
- Measure the distance between the center (upper surface) of the pedal pad and the floor pad.
- If out of specifications, loosen the brake light switch.
- Turn the pedal pushrod until the pedal height is within specifications.
- Move the brake light switch until the body is just touching the pedal stopper. Tighten the switch.
- Check the brake pedal free-play.
See Figure 6
- With the engine turned off, depress the brake pedal several times until there is no vacuum left in the brake booster.
- Push the pedal down until resistance is first felt. Measure this distance.
- Adjust the free-play by turning the pedal pushrod.
- Start the engine and recheck the free-play.
- Recheck the pedal height.
See Figures 7 and 8
Depress the brake pedal to the bottom of the pedal travel and measure the distance from the center (upper surface) of the pedal pad to the floor mat. If the distance is out of specifications, recheck the other pedal adjustments and the master cylinder.