The method of brake adjustment varies depending on whether the vehicle is equipped with cam adjustment brakes or star wheel adjustment brakes with self-adjusters. When the brake linings become worn, effective brake pedal travel is reduced. Adjusting the brake shoes will restore the necessary travel.
Before adjusting the brakes, check the spring nuts, brake dust shield-to-axle flange bolts, and wheel bearing adjustments. Any looseness in these parts will cause erratic brake operation. Also make sure that the brake pedal has the correct amount of free travel without moving the master cylinder piston (free-play). There should be about 1 / 2 in. (13mm) of free-play at the master cylinder eye bolt. Turn the eye bolt to adjust the free-play.
Release the parking brakes and centralize the brake shoes in the drums by depressing the brake pedal hard and then releasing it. It is best to have all four wheels off the ground when the brakes are adjusted so that you can go back to each wheel to double check your adjustments.Initial Brake Shoe Adjustment
If the brake assemblies have been disassembled, an initial adjustment must be made before the drum is installed. It may also be necessary to back off the adjustment to remove the drums.
When the brake parts have been installed in their correct position, adjust the adjusting screw assemblies to a point where approximately 3 / 8 in. (9.5mm) of threads are exposed between the star wheel and the star wheel nut.Brake Adjustment
See Figures 1 and 2
- Raise up the vehicle until all of the wheels, or at least the one to be adjusted first, are off the ground. Support the vehicle safely on jackstands.
- Turn the forward shoe adjusting cams on the left side of the vehicle clockwise until the shoes are tight against the drums. Then turn the cams in the opposite direction until the wheels rotate freely without brake drag.
- Turn the rear adjusting cams on the left side counterclockwise until the shoes are tight against the drums. Then turn the cams in the opposite direction until the wheels rotate freely without brake drag.
- Repeat the two steps given above on the right side of the vehicle, turning the forward shoe adjusting cams counterclockwise and the rear shoe adjusting clockwise to tighten.
On CJ-2A and CJ-3A models, if additional adjustment is required or when installing new brakes, reset the anchor pins as follows:
- With the brakes installed and the drum in place, loosen the anchor pin locknuts at the bottom of the backing plate.
- Turn the anchor pins in toward each other until the brake shoe-to-drum clearance is 0.005 in. (0.127mm) at the lower end of the shoe and 0.008 in. (0.203mm) at the upper end. On early models, a slot in the brake drum was provided to measure this clearance. The slot was eliminated on later models.
See Figure 3
- Raise and support the vehicle on jackstands.
- Remove the access slot cover and using a brake adjusting tool or screwdriver, rotate the star wheel until the wheel is locked and can't be turned in the clockwise direction.
- Back off the star wheel until the wheel rotates freely. To back off the star wheel on the brake, insert an ice pick or thin screw driver in the adjusting screw slot to hold the automatic adjusting lever away from the star wheel. Do not attempt to back off on the adjusting screw without holding the adjusting lever away from the star wheel as the adjuster will be damaged.