Note: Before you begin, please read the warnings at the beginning paragraph 4, about the harmfulness of asbestos dust.
Examination
Note: To maintain uniformity and braking efficiency, both discs are replaced if at least one requires replacement. At the same time, the brake pads are also replaced with new ones.
1. Place chocks under the rear wheels, apply the handbrake and raise the front of the car. Install safety stands. Remove the corresponding wheel. When removing the wheels, tighten one bolt into each hub to prevent the brake discs from shifting relative to the hub. If necessary, use washers or old large nuts.
2. If you need to increase visibility, remove the brake pads. Turn the disc and check the depth of the grooves and potholes. Small potholes "have a right to be", but excessive ones indicate the need for replacement.
3. A common occurrence is the formation of a rusty crown around the perimeter of the disc, it can be removed if necessary. Check the top tire of the disc with a micrometer. Take measurements in several places. If at least one place the thickness of the disc has decreased less than the permissible Specifications, both disks must be replaced.
4. If there is a suspicion that the disc is bent, use a dial indicator or a ruler with a set of feeler gauges to check the disc runout and compare it with the tolerances given in Specifications. To take measurements, secure the disc with at least two wheel mounting bolts, using flat washers to ensure the disc sits correctly on the hub.
5. Measurements should be taken approximately 10 mm from the outer edge of the disc. Measure the runout at several radii of the disc. If the disc runout exceeds the permissible limit, remove the disc and make sure that the mating surface of the disc and the hub is absolutely clean. If the runout exceeds the permissible limit, the disc must be replaced. But first check the condition of the hub - see. chapter 10.
6. Check for disc cracks (especially around the wheel mounting bolts). Replace the disk if necessary.
Removal
7. Unscrew the two bolts securing the caliper to the steering knuckle and remove the caliper. Tie the caliper to the suspension strut with a piece of wire so as not to put stress on the brake hose. If necessary, the bracket for mounting the caliper can be removed by unscrewing the mounting bolts as described in paragraph 8.
8. If the disc is to be installed backwards, mark its position relative to the hub with paint or chalk. Unscrew the bolts that secure the disc to the hub, screwed in when checking the disc, and remove the disc. If the disc is not seated properly, help it come off with a rubberized hammer.
Installation
9. Installation is the reverse procedure of removal. Please note the following:
- a) The mating surfaces of the disc and hub must be clean and smooth.
- b) If present, align the previously applied marks.
- c) If installing a new disc, use a suitable solvent to remove the protective grease from the disc before installing it on the hub.
- d) Before installation, clean the caliper mounting bolts, place the bracket on the pads and tighten the mounting bolts to the specified torque.
- d) Install the wheel and lower the car. Tighten the wheel mounting bolts to the specified torque. Finally, press the brake pedal several times to allow the pads to approach the disc and take up working position.