Caravan AWD V6-201 3.3L (1991)
Brake Disc: Testing and Inspection
NOTE: If a vehicle has not been driven for a period of time, the discs will rust in the area not covered by the lining and cause noise and chatter.
NOTE: Some discoloration or wear of the disc surface is normal and does not require re-surfacing when linings are replaced.
CAUTION: Any servicing of the braking disc requires extreme care to maintain the braking disc within service tolerances to ensure proper brake
action.
BEFORE REFINISHING OR REFACING A BRAKING DISC INSPECT FOR:
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Scoring, rust, impregnation of lining material and worn ridges.
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Excessive wear and scoring of the disc
CAUTION: Excessive wear and scoring of the disc can cause temporary improper lining contact if ridges are not removed before installation of
new brake shoe assemblies.
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Runout or wobble
CAUTION: Excessive runout or wobble in a disc can increase pedal travel due, to piston knockback This will increase guide pin bushing wear
due to tendency of caliper to follow disc wobble.
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Thickness variation (Parallelism).
NOTE: Thickness variation in a disc can also result in pedal pulsation, chatter and surge due to variation in brake output when disc section is
uneven.
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Dishing or distortion (Flatness).
NOTE: Dishing or distortion can be caused by extreme heat and abuse of the brakes.
SPECIFICATION - See: Specifications
Fig 1 Checking Total Indicated Runout (TIR)
MEASURING TOTAL DISC RUNOUT ON VEHICLE:
NOTE: On Vehicle, Braking Disc (rotor) Runout is the combination of the individual runout of the hub face and the runout of the disc. The hub
and disc are separable.
NOTE: Before checking the runout, wheel bearings should be adjusted.
1. Remove the wheel and reinstall the lug nuts to tighten the disc to the hub.
2. Mount dial indicator with adapter on steering arm with plunger contacting disc braking surface approximately one inch from edge of disc.
3. Check lateral runout (both sides of disc).
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Runout should not exceed 0.13mm (0.005 inch).
