The pads should be removed so that the thickness of the remaining friction material can be measured. If the pads are less than 2mm (0.08 in.) thick, they must be replaced. This measurement may disagree with your state inspection laws.
Always replace all pads on both wheels at the same time. The factory kit includes four pads, slips, pins, and springs; all parts should be used.
REMOVAL & INSTALLATION
See Figures 2, 3 and 4
- Raise and support the front of the truck. Remove the wheels.
- Remove the retaining clip from the outboard pad.
- Remove the pad pins retaining the anti-squeal springs.
- Remove the pads.
When replacing the pads, always check the surface of the rotors for scoring or wear. The rotors should be removed for resurfacing if badly worn.To install:
- Open the bleeder screw slightly and push the outer piston into the cylinder until the dust seal groove aligns with the end of the seal retaining ring, then close the bleeder screw. Be careful, because the piston can be pushed too far, requiring disassembly of the caliper to repair. Install the inner pad.
- Pull the yoke to push the inner piston into place. Install the outer pad.
- Lightly coat the areas where the pins touch the pads, and where the pads touch the caliper (at the top) with grease. Do not allow the grease to get on the pad friction surfaces.
- Install the anti-squeal springs and pad pins. Install the clip.
- Apply the brakes a few times to seat the pads. Check the master cylinder level; add fluid if necessary. Bleed the brakes if necessary.
See Figure 1
See Figure 5, 6, 7, 8, 9 and 10
- Remove the hub cap and loosen the lug nuts.
- Raise the front of the truck and safely support it with jackstands.
- Remove the lug nuts and the wheel.
- Attach a clear vinyl tube onto the bleeder plug on the brake cylinder, and insert the other end into a jar half filled with brake fluid. Bleed off a small amount of brake fluid.
- Remove the caliper slide pin bolt on the sub-pin (lower) side.
- Swivel the caliper up and away from the torque plate. Tie the caliper to a suspension member so its out of the way. Do not disconnect the brake line.
- Lift the 2 brake pads out of the torque plate.
- Remove the inner and outer shims. Remove the 2 pad retainers if they are not still attached to the pads.
- Check the pad thickness and replace the pads, if necessary.
This minimum thickness measurement may disagree with your state inspection laws.To install:
- Install the inner and outer shims into the torque plate.
- Install a pad retainer to the bottom of each pad.
- Install the pads into the torque plate.
- Use a C-clamp or hammer handle and press the caliper piston back into the housing.
Never press the piston into the caliper when the pads are out on both sides of the truck.
- Untie the caliper and swivel it back into position over the torque plate so that the dust boot is not pinched. Install the slide pin and tighten it to 16-23 ft. lbs. (22-31 Nm) on 1984-86 models (720D series); or 53-72 ft. lbs. (72-97 Nm) on 1986-88 models (D21-D series).
- Check the condition of the cylinder side bushing boot. Pull on it to relieve any air from the cylinder side pin mounting area. Check that the hole plug on the main pin side is there. Push on the center of the plug to relieve any air from the inner portion of the main pin.
- Install the wheel and lower the truck. Bleed the brakes and road test the vehicle.