REMOVAL & INSTALLATION
- Remove the brake caliper and pads as described earlier in this section.
Do not disconnect the rear brake hose and make sure to hang the caliper from the vehicle's frame with strong wire or cord.
- The rear brake rotor is held in place by the wheel and wheel nuts. In some cases, the rotor is also held onto the rear axle hub with 2 or 3 retaining nuts (on the wheel lug studs).
- The 1988 models (except Premier and Monaco) have a rear brake adapter which must be removed before the rotor can be pulled off of the hub. Remove the 2 mounting bolts from the rear and separate the adapter from the brake assembly.
- Before removing the rotor, matchmark it and one adjacent wheel stud so it may be installed in the same position.
- After removing the retaining nuts, if applicable, the rotor can simply be pulled off the studs.
- Slide the new rotor onto the hub studs so that the matchmarks line up. If retaining nuts were used to retain the rotor, install the retaining nuts until snug.
- If applicable, install the brake adapter. Tighten the adapter mounting bolts to 130-190 ft. lbs. (176-258 Nm).
- Install the brake caliper and pads. For more details, refer to the caliper installation procedure located earlier in this section.
See Figures 1, 2 and 3
Inspect the disc for scoring, rust, impregnated lining material and ridges, and replace or machine it if serious problems in these areas are visible. Take the following specific measurements:
- With the wheel removed, install the lug nuts to hold the disc snugly in place against the hub. Then, mount a dial indicator so it will read runout about 1 in. (25.4mm) from the outer edge of the rotor. Zero the indicator, rotate the disc, and read the maximum reading. Compare the reading with the specification in the brake specification chart located at the end of this section.
- If the specification is excessive, remove the rotor and repeat the process, this time mounting the indicator so as to measure the runout of the hub. This must not exceed 0.003 in. (0.076mm). If it does, the hub requires replacement. If hub runout meets the specification and disc runout does not, replace the disc or have it machined, if it can be trued up while maintaining minimum thickness specifications (stamped on an unmachined surface). Note that this specification includes 0.030 in. (0.76mm) wear beyond the maximum machining limit of 0.030 in. (0.76mm) from original thickness.
- Use a micrometer to measure disc thickness at 4 locations. Thickness variation must not exceed 0.0005 in. (0.013mm). If thickness variation can be corrected by machining the disc while maintaining maximum thickness limits, this may be done.
All brake discs or rotors have markings for MINIMUM allowable thickness cast on an unmachined surface or an alternate surface. Always use this specification as the minimum allowable thickness or refinishing limit. Refer to a local auto parts store or machine shop if necessary shop where brake disc or rotors are resurfaced.
If the brake disc or rotor needs to be replaced with a new part, the protective coating on the braking surface of the rotor must be removed with an appropriate solvent.