General guide to replacing brake rotors

  1. Brake Disc rotors must be replaced by a qualified mechanic.
  2. The following fitting instructions are supplemental to the instructions contained in the manufacturer’s workshop manual.
  3. Please remember adb disc rotors are warranted for street use only and not for any type of motor sport or racing unless stated.
  4. Regular Inspection of your motor vehicle brakes is essential for safety.

1. Compare and ensure they are the correct rotors.
Never allow the rotor braking surface and friction material to come in contact with mineral oil based cleaning agents, grease or oil.
REMOVE RUST PREVENTIVE COATING FROM ROTOR BRAKING SURFACE using non-oil based solvent failure to do this can result in new brake pads overheating and noise. It is a safety requirement that the braking surfaces be free of any oil or grease.


2. Establish the reason for replacing rotors. If it’s not due to normal wear and tear find the cause and correct it so it
will not re occur
3. Check all mating & wearing parts for evidence of abnormal wear, the friction area, caliper slides rotor and pads.
4. Uneven pad wear can indicate, a seized caliper or slide, or constant line pressure when brakes are not in use
5. Replacement should be in axle sets. Do not replace one side only as this can cause unbalanced braking.
6. If abnormal wear is suspected we recommend you contact your qualified mechanic.


7. Remove the wheel and brake caliper assembly, complete if possible, disconnection of the brake pipe can result in possible fluid spillage and will require additional brake bleeding.
8. Do not let the caliper hang on the brake pipe. Avoid strain on the brake pipe. Secure caliper.
9. Remove the worn brake disc.


11. Use wire brush, sand paper to clean hub surfaces see Picture 1, 2 & 3.
12. CAUTION: Failure to ensure surfaces mate perfectly will result in rotor run out.


13. Check that the caliper slides are clean and not damaged and that the brake pads move freely on the slides.
14. Reassemble the brake caliper and depress the brake pedal until the pistons and pads are re positioned.
15. Check brake fluid levels and top up or replace fluid as necessary.
16. Check that the brake pads and brake disc contact correctly before road testing the vehicle.


Bearing torque adjustment
17. Check bearing cone and hub seal are both seated all the way into their respective recesses.
18. The hub seal must not be level it must be below the housing; otherwise it will jam on the stub axle making it impossible get a correct bearing adjustment.
19. Rotate the rotor while tightening the castle nut to 30Nm to seat the bearing,
20. Loosen castle nut ½ turn and re-tighten to 1.5Nm.
21. Install split pin and grease cap.
22. Check that the bearing play does not exceed the manufacturers tolerances

Causes of incorrect bearing torque adjustment
23. If the castle nut is too tight, this will cause rotor drag and excessive wear on the bearings.
24. If castle nut is too loose, rotor run will occur.
25. If the hub seal fouls on the stub axle correct bearing adjustment is impossible, rotor run out will occur

ADB brake rotors are all machined and double milled for perfect parallelism BEFORE LEAVING THE FACTORY.

Rotor Run-out Test (RRT).

26. Rotor Run-out test should not exceed 0.10mm.
27. If this is exceeded remove the disc and recheck all mating surfaces.
28. Check that the bearing cone and hub seal are pressed all the way down into the recess. Must not protrude above casting.
29. Check that the hub seal and the end of the stub axle are not forced against each other as this will make the correct bearing adjustment impossible.
30. Remount the disc in a different position, and check for run-out again

Disc Thickness Variation DTV is when rotor run out causes abnormal wear to the part of the rotor surface constantly hitting and rubbing against the pads even when the brakes are not applied. Then when the brakes are applied this can result in a bad pedal feel, pulsating or shuddering pedal, knocking noise and in some cases a vibration through the steering.

Road test/Bedding-in, in order to get the maximum performance out of your new brakes;
31. Road test: Whilst driving vehicle at low speeds up to 40km/hr apply brake slowly with light to moderate brake applications each 200metres, repeat 5 times.
32. Bedding-in: Avoid high speed or aggressive braking during first 100 km to allow the rotors and pads to bed-in to avoid heat spots and the subsequent reduction in braking efficiency.

ABS Brakes with Sensor Ring
Check that the sensor ring on the new rotor supplied has the same number of teeth as the one removed.
If the rotor supplied is without the sensor ring the old one must be removed and re fitted to the new rotor.
Ensure the sensor ring run out is within the manufacturer’s specification after re-fitting the pole ring.

Caution when removing and refitting sensor ring.
Do not fit a sensor ring with a different number of teeth
Take care not to strike the sensor ring on the tip of the speed wheel sensor
These two things can affect (cause longer) stopping distances and Record a fault in the ABS computer system.

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