Removal and installation the front brake guide (BMW 3 Series E46)

If the brake caliper and bracket are disconnected only to remove the brake disc, do not disconnect the brake hose. Otherwise, the brake system must be bled after installation. Hang the caliper on a wire from the suspension so that the hose is not twisted or stretched.

Removal

1. Mark the position of the corresponding front wheel relative to the hub with paint. This will allow the balanced wheel to be installed in its original position during assembly. Loosen the wheel mounting bolts with the car on the ground. Raise the front of the car, place it on stands and remove the front wheel.

2. Press the brake pedal lightly and hold it in this position. To do this, you can insert a wooden block between the seat and the pedal. To do this, move the seat back and then forward again. This eliminates the possibility of brake fluid leaking out of the reservoir after disconnecting the hoses and air getting into the system.



3. Disconnect the pipeline from the coupling (arrows in the illustration), otherwise it is impossible to disconnect the brake hose at the caliper.

Some brake fluid may leak out. Collect it in a bottle that is designated for brake fluid only.

4. Disconnect the wear indicator connector at the left caliper "1". Do not pull on the cable.



5. Unscrew the mounting bolts "1" of the brake caliper and remove the caliper with the caliper and the brake pads inserted.

Installation

1. Measure the thickness of the brake disc, refer to Section Measuring the thickness of the brake disc.

2. Put the brake caliper with the brake pads in place.

If the brake hose is connected, make sure it is not twisted or pulled. Check that the brake hose moves freely when the steering wheel is turned all the way.

3. Secure the brake caliper with lightly greased bolts to a torque of 110 Nm.

4. Connect the wear sensor connector to the left side of the vehicle near the brake pad. The wire should pass through the loop of the air bleed nipple cover



5. Set the car wheels straight. Install the brake hose at the connection holder and secure the hose with a union nut. Make sure that the hose does not twist. Check the free movement of the hose when the steering wheel is fully shifted.

6. Bleed the brake system, refer to Section Bleeding the brake system.

7. Reinstall the front wheels so that the markings applied during removal match. Pre-lubricate the wheel disc seat on the hub with a thin layer of bearing grease. Do not lubricate the wheel mounting bolts. Replace rusty bolts with new ones. Secure the wheels with bolts. Lower the car onto the wheels and tighten the mounting bolts crosswise to a torque of 100 N·m.

8. Turn the steering wheel right and left to the stop and check whether the brake hose follows all wheel movements with the vehicle standing on its wheels.

Press the brake pedal hard several times while standing until you feel resistance. This will ensure that the brake pads are in their working position against the brake disc.

9. Check the brake fluid level in the reservoir, if necessary, add fluid to the MAX mark.

• Are the brake hoses secured?
• Is the brake hose secured in the holder?
• Are the air bleed nipples tightened?
• Is there enough brake fluid?
• With the engine running, check for leaks. To do this, press the brake pedal with a force of 200–300 N (20–30 kg) for 10 s. The pedal should not weaken. Check all connections for leaks.

Brake fluid should never be poured out or thrown away with household waste. Local authorities inform drivers about possible disposal sites.

(This publication was borrowed from an online resource: BMWMan)