Front brake pads — removal and installation (BMW 7 Series E32)

Removal

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

Note: If the pads are to be used further, they must be marked when removed. Replacing the pads from the right to the left wheel and vice versa is not allowed. Such a replacement may result in uneven braking. When replacing, use only original pads and replace the pads on both wheels when the wear limit of the pads is reached.

Use your fingers to pull out the sensor plug on the left brake caliper.



Use a screwdriver to pry off the plastic caps of the mounting bolts.



Do not pull on the wire.



Unscrew the bolts located under the caps using a 7 mm Allen key.

Press the bracket with a screwdriver.



Pull the caliper back and hang it on the body with wire.

Caution: Do not disconnect the brake hose, otherwise you will have to bleed the brakes after installation. Make sure that the brake hose is not stretched.

Remove the brake shoe.



The inner brake shoe is secured to the caliper piston by a spring. Remove the shoe.

Installation

Caution: When the brake pads are removed, do not press the brake pedal, otherwise the pistons may jump out of the caliper housing.

Check the brake pad wear sensor. If the contact plate insulation is worn out, the wire insulation is damaged or the plastic parts are worn out, replace the wear sensor.

Clean the guide planes or the pad seats in the caliper body channel with a soft metal brush or wipe them with a rag soaked in alcohol. Do not use mineral solvents or sharp tools. If the brake pads are reused, they should be cleaned as well.



Before installing the pad, the brake disc should be checked by touch to detect scratches and dents. Badly scratched discs should be replaced. Brake discs that are painted grayish or bluish should be cleaned.





Measure the thickness of the brake disc.

Check the dust cover on the piston for damage. Damaged covers should be replaced immediately, as dirt will cause leaks in the caliper. To replace, remove the caliper and disassemble it (in the workshop).





Press the piston into the brake cylinder using a special tool. You can use a block of hard wood (with a hammer handle). In this case, you need to be careful not to skew the piston or damage the piston surface and dust cap.

Note: When you press the piston, brake fluid will be squeezed into the fluid reservoir. You need to monitor the fluid level in the reservoir and, if necessary, remove it with a syringe or rubber bulb.

Brake fluid is poisonous and should never be sucked out by mouth through a hose. After replacing the pads, the level should not exceed the MAX mark on the reservoir, as the fluid expands from the temperature and can escape from the reservoir, which will damage the paintwork and cause corrosion.

Note: If the pads are heavily worn, check the ease of movement of the piston. To do this, insert a wooden block into the caliper and have an assistant slowly press the brake pedal. The brake piston should slide in and out easily. Another caliper must be installed to check. Make sure that the piston is not completely squeezed out. If the piston moves heavily, have the caliper repaired in a workshop.

To prevent disc brakes from squeaking, it is necessary to lubricate the following parts with a thin layer of a special paste.

Clean the contact surface (3) of the brake caliper and, in the places shown in the figure, apply a thin layer of anti-noise paste.



Clean the brake caliper holder (bracket) in the guide areas and, in the areas shown in the figure, lubricate with a thin layer of anti-noise paste.

Caution: The paste must not under any circumstances come into contact with the dust caps, the working surface of the brake pads or the brake disc. If this does happen, the paste must be wiped off immediately and the area cleaned with alcohol or the dust caps must be replaced.

Caution: Do not lubricate the back of the brake pads.

Insert the brake shoe together with the spring into the brake piston.



Insert the outer pad into the caliper and place the caliper onto the brake disc. Make sure that the pads are clean when installed into the guides.

Inspect the two brake caliper mounting bolts, clean the threads from dirt if necessary. If necessary, clean the threads in the caliper bracket (mount) with a tap. Replace bolts with damaged threads or damaged by corrosion. Tighten the bolts with a hex key to 30 Nm.

Caution: Bolts must be cleaned, do not lubricate them.

Place the protective bolt caps on.



Place the wear sensor plug on the left side of the brake shoe. The wire should fit into the recess in the bleed valve cap.

Place the bracket on the brake caliper.

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

Note: With the vehicle stationary, press the brake pedal hard several times until you feel strong resistance. This will cause the brake pads to press against the brake disc and take the appropriate position.

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

Please perform a security check:

• Are the brake hoses tight?
• Is the brake hose in the bracket?
• Are the air bleed valves tightened?
• Is there enough brake fluid in the reservoir?
• Conduct a tightness test with the engine running. To do this, press the brake pedal with a force of 200-00 N (corresponds to 20-30 kg) for about 10 seconds. The pedal should not drop. Check all brake system connections for tightness.

Carefully break in the new brake pads by braking the car several times from 80 km/h to 40 km/h on a road with little traffic, applying light pressure to the pedal. Allow the brakes to cool slightly between brakings.

Caution: Avoid sudden braking until the distance reaches 200 km.