Removal and installation the rear brake disc with rear disc brakes. Models 325E/325i (BMW 3 Series E30)

Removal

Remove the rear wheel brake caliper.

Loosen the mounting bolt (arrow) using a 5 mm open-end wrench.



Release the parking brake completely.

Remove the brake disc. If the brake disc cannot be removed, separate the brake pads (see section "Parking brake").

Installation

To ensure uniform braking on both sides, the surfaces of both discs must be identical in surface finish and treatment. Therefore, it is necessary to replace both discs at the same time.

The service station can check the disc runout. Maximum lateral runout (in the installed position): 0.2 mm.

Measure the thickness of the disc (see section "Checking the thickness of brake discs").

Installation

Clean new disks with nitro solvent to remove protective varnish.

Place the brake disc on the wheel hub and secure with a bolt. First, turn the brake disc so that the holes for the bolt align.

Install the brake caliper with the brake pads inserted. Do not stretch or twist the brake hose. Check that the brake hose moves freely when turning the steering wheel from lock to lock. Tighten the brake caliper (see section "Removal and installation the rear wheel brake caliper").



Secure the brake caliper with a bolt tightening torque of 120 Nm. Pre-coat the bolt threads with engine oil.

Caution: If the brake hose has come loose, it is necessary to bleed the brake system (see section "Bleeding the brake system").

Install the wheel observing the marking of the disk position on the hub. Lower the car and cross-tighten the wheel bolts to a torque of 110 Nm.

Caution: With the vehicle stationary, press the brake pedal several times until you feel a noticeable resistance.

Check the brake fluid level in the expansion tank, if necessary, top up the fluid to the MAX mark (see section "Checking the brake fluid level and the brake fluid level warning light").

Break in new brake discs in three stages.

• Phase 1: 5 hard braking applications at 50 km/h on a road with light traffic.
• Phase 2: Allow the brakes to cool.
• Phase 3: 5 more hard braking at 50 km/h.

[You can read the original on the website: «bmwman»]