Note. The procedure is equally applicable to both front and rear disc brakes.
Status check
1. Loosen the wheel nuts, jack up the vehicle and place it on jack stands. Remove the wheel in question, then screw a pair of wheel nuts back onto the mounting studs with 3mm washers underneath to secure the brake disc (if the two disc fixing screws are not yet removed, there is no need to tighten the nuts). When checking the rear brake disc, be sure to release the parking brake.
2. Remove the brake caliper (see Section Removal and installation of brake calipers) and tie it aside with a wire to the suspension element without disconnecting the brake hose.
3. Make a visual check of the state of the working surface of the disk. Light defects can be removed with fine-grained sandpaper. To remove grooves deeper than 0.38 mm, the disc should be machined. Remember that the disc must be inspected from both sides.
4. If pedal pulsations are noticed during braking, the magnitude of the lateral runout of the brake disc should be assessed. Attach plunger type dial gauge (DTI) at a distance of about 12.7 mm from the outer edge of the disc.
5. Zero the instrument and start rotating the disc. The measurement result should not go beyond the allowable range specified in the Specifications, otherwise the disk must be given to the groove.
Note. The compilers of this Guide recommend turning the discs, regardless of their condition, in order to remove all kinds of defects from the working surfaces. In extreme cases, you can limit yourself to processing the disk with fine-grained sandpaper.
6. When turning a disc, special attention should be paid to compliance with the requirements of the Specifications for its minimum allowable thickness. The corresponding marking is provided on the end surface of the disk.
7. Measuring the thickness of the disc is done with a micrometer.
Withdrawal
1. Turn out two bolts of fastening of an anchor bracket of a support to a rotary fist,
2. or (on the rear wheel brake) bolts securing the bracket to the hub assembly. Remove the bracket.
3. Remove the two wheel nuts used to secure the disc to the hub/remove the two mounting screws. Remove the disc from the wheel hub.
4. If the disc "stuck" to the hub, it can be squeezed out by screwing a pair of bolts of a suitable size into the mounting holes. Tighten the bolts evenly and progressively until the disc is completely loose. When removing the disc, take care not to damage the threads of the wheel studs.
Installation
1. Gently slide the disc onto the hub (again try not to damage the wheel studs). Screw in and firmly tighten the fixing screws.
2. Install the caliper anchor bracket on the disc. Tighten the bracket and caliper mounting bolts to the required torque.
3. Replace the wheel, lower the vehicle to the ground and tighten the wheel nuts to the required torque (see Specifications to Chapter Settings and ongoing maintenance). Depress the brake pedal/cock the parking brake lever several times to seat the pads on the disc. If the brake hoses have not been disconnected, there is no need to bleed the hydraulic system. Before starting the operation of the vehicle, make sure that the brakes are working properly.