TSB : Rear Brake Pads, Replacement (Live Rear Axle)

Details

REAR BRAKE PADS, REPLACEMENT (LIVE REAR AXLE) Special tools: 999 2809, 2917, 2918 E1. Jack up and support rear of car. Remove wheels Mark wheel positions if locating studs are not fitted. E2. Remove: ^ split pins (use 3 mm drift) ^ spring plate ^ brake pads Use extractor 999 2917 if pads are stuck. E3. Inspect components Carefully clean pad locations. Caliper must be reconditioned if dirt has entered cylinders due to damaged dust seals. Inspect disc friction surface. Replace disc if component shows signs of severe wear, distortion, variation in thickness or other conditions. E4. Press brake piston back fully Press back pistons slowly using adjustable pliers or press tool 999 2809, taking care to avoid damage to dust seals. Sluggish movement of the pistons, as indicated by failure of the pistons to return to their original position when pressed inward, may be due to oxidation. Caliper must be reconditioned if this is the case. Note: Level in brake fluid reservoir may rise when pistons are pressed back, causing fluid spillage. E5. Clean caliper It is essential to clean caliper thoroughly, for example when replacing pads. Steel brush may be used. Leave anti-squeal shims in position to protect piston dust seals. Minimizing rear brake noise An anti-squeal shim should be installed as follows (see illustration) to minimize squealing or screeching. A = stainless steel anti-squeal shim (P/N 13 59 772-9). Install nearest piston (two per caliper) B = coated anti-squeal shim, P/N 12 28 590-4. Install nearest pad backing plate (two per caliper). C = pad backing plate. Note: Anti-squeal shim B: Lubricate shim on both sides with thin coating (approx. 0.1-0.2 mm = 0.004-0.008 inch) of silicone grease, P/N 11 61 325-4. Anti-squeal shim B is included temporarily in kit, P/N 12 28 590-4. The shim will eventually be discontinued and the pad backing plate provided with an anti-squeal coating. Thus, on cars with coated pad backing plates: Use antisqueal shim A lubricated with silicone grease, P/N 11 61 325-4. E6. Check piston orientation if brake noise is present Brake noise on earlier models in which the piston rim is provided with an opening may be minimized by installing the piston with the opening facing forward. Use tool 999 2918. Note: The illustration shows a mirror image of the piston rim imposed on the shim. E7. Inspect disc friction surface and measure disc thickness Replace disc if component shows signs of severe wear, distortion, variation in thickness or other conditions. Brake disc thickness mm (inch) New disc: Min. recommended disc thickness when replacing pads; absolute min. thickness E8. Install: ^ brake pads ^ one split pin and new spring plate ^ second split pin E9. Check level in brake fluid reservoir . Operate brake pedal repeatedly E10. Refit wheels as per markings Finger-tighten nuts, then torque diagonally to 85 Nm (63 ft. lbs.) .