Brake disc — removal and installation (BMW 7 Series E32)

Note: If the brake caliper is removed only to remove the brake disc, do not unscrew the brake hose, otherwise you will need to bleed the brake system after installation. The caliper must be suspended on a wire so that the brake hose is not twisted or stretched.

Removal

Mark the position of the front wheels on the hubs so that you can later install the balanced wheels in their original positions. Loosen the wheel bolts with the car on the ground. Raise and support the car in front and remove the front wheels.

Lightly press the brake pedal and hold it in this position. To do this, insert a spacer between the driver's seat and the brake pedal. If necessary, move the seat forward or backward. This will prevent brake fluid from leaking out of the reservoir after disconnecting the brake pipes and air from entering the hydraulic system.

Disconnect the brake pipe from the connection with the brake hose. The brake hose does not need to be unscrewed from the caliper.

Note: This may cause some brake fluid to spill out, which should be collected in a suitable container.

Unscrew the caliper mounting bolts and remove the caliper from the brake disc.



Loosen the mounting bolt using a 5mm Allen key.





Remove the brake disc.

Caution: Ventilated brake discs are balanced. The balancing brackets on the inner diameter of the brake disc must not be removed or moved.

Installation

To ensure uniform braking on both sides, both brake discs must have the same wear pattern on their working surfaces and wear depth. Therefore, both brake discs must always be replaced or reground.

The workshop can check the runout of the brake discs. The maximum runout of the installed disc on the working surface should be 0.2 mm.



Measure the thickness of the brake disc.



If present, remove rust from the brake disc flange and from the front wheel hub.



Clean new brake discs from protective varnish with solvent or acetone.

Install the brake disc on the front wheel hub and secure it with Allen-head bolts. Before doing this, you need to turn the disc so that the bolt holes line up.

Install the brake caliper with the brake pads inserted.

Caution: If the brake hose is connected, make sure it is not twisted or stretched. Check the movement of the brake hose when the steering wheels are turned to the stop.

Tighten the lightly lubricated caliper mounting bolts to 110 Nm.

Set the front wheels in the straight-ahead position. Insert the brake hose into the holder and tighten the union nut of the brake pipe. Make sure that the brake hose does not rotate. Check the movement of the brake hose when turning the front wheels from lock to lock.

Bleed the brakes.

Install the front wheels according to the marks made during removal. Do not lubricate the wheel bolts. Lower the vehicle and tighten the wheel bolts crosswise to 100 Nm.

Turn the steering wheel from lock to lock and check that the brake hoses follow all movements of the steering wheels and do not rub against other parts.

Caution: Press the brake pedal several times with the vehicle on the ground until you feel a firm resistance. This will cause the brake pads to contact the brake discs and take the appropriate working position.

Check the brake fluid level in the reservoir and, if necessary, top it up to the MAX mark.

Conduct a security check.

(The original article is posted on the resource: «bmwman.ru»)