# Pads, disc brake, replace.

Break torque on wheels to be removed.
Raise and support the vehicle on appropriate stands. NEVER work under a car supported by a jack.
Remove wheels from axle where brakes are to be serviced. |
Remove retainer clip on the front of the caliper by prying it towards caliper and pulling off. |
CAUTION: Spring is under tension. Keep hand over spring to catch it when it releases.
Calipers are secured to the bracket by two 7mm Allen bolts that double as slide pins. Bolts are located behind plastic caps (arrows), remove caps and loosen bolts. There is no need to remove the bolts entirely, simply unscrew them until they come free of the caliper bracket and leave them in their rubber housings. |
There is no need to remove the bracket if replacing pads only. However, it must be removed to replace rotors.
Grab caliper and pull it towards the face of the rotor, in a twisting motion, this will force the piston back into the caliper enough to allow you the clearance to remove the caliper from the rotor. The older the rotors, the more clearance you will need to get past the lip on the outer edge of the rotor. If the rotors have a 1mm or greater lip, they should be replaced. |
NOTE: Do not let a caliper hang by its rubber brake hose, this can result in damage to the ends of the rubber hose which could cause a dangerous situation at a later date.
Push piston completely into caliper, use a large set of pliers or a C clamp, push straight in and do so slowly with even pressure. Piston should slide in almost flush with housing. Take care not to damage the dust seal. If piston will not slide back into caliper, replace or rebuild caliper.

#### NOTE:
BMW brake systems are sealed systems, there should be no need to add fluid to a BMW system unless it has a leak. If the brake fluid light comes on and no leak is present , it is because all brake pads are getting low and extra fluid has been displaced into the lines to compensate for the extra piston travel from worn pads. In this case, the pads should be changed. In many cases, whether from flushing the brakes with half worn pads, or just the owners concern, the brake fluid reservoir gets topped off. In this case, pressing the piston back into the caliper will result in an overflow of fluid from the reservoir. This can be prevented in two ways. Before starting the job, check the level of the fluid, if it is below the Maximum level, and you are only doing one axle, you can do one wheel at a time, pumping the brake pedal after each wheel is reassembled to displace some of the fluid from the reservoir. Or, if the fluid is higher than the Max level, or you are doing all 4 wheels, drain some fluid from the reservoir with a clean syringe such as a turkey baster.

While it is possible to re-use brake lining sensor, if the light is not on, they are difficult to remove without breaking, and should be replaced as a matter of course. Sensors are located on the front left and rear right inboard pads. |
Install new sensor in inboard pad, at the right rear and left front. |
Clean the caliper and bracket of brake dust and old lube with an aerosol parts and brake cleaner. |
DANGER: Brake dust can contain asbestos, and even if it does not, it can still cause health problems. NEVER use compressed air or a brush to remove dry brake dust, always wet brake dust down before brushing.
Apply a thin coat of anti squeal grease to the rear of the pads, and to the contact points in the caliper. Take care not to get grease on face of pad.
Insert pad with three prongs on back into caliper, pressing prongs into caliper. Place outer pad on caliper bracket and install caliper over the top. Thread sensor through opening if applicable.
NOTE: Ensure that piston dust boot does not get caught between piston and pad.
Ensure that the brake sensor wires are correctly positioned under the bleed valve dust cap to prevent them from rubbing on the wheel.
Install clip by placing ends on caliper bracket (arrow) and pushing center into holes on caliper. |
CAUTION: Pump brake pedal several times before starting car, to ensure braking pressure is available before car starts moving.
There is no requirement to bleed brakes after changing pads. |

### Part numbers:

Front brake pads | : | 34 11 2 226 084
Front brake sensor | : | 34 35 1 180 782
Rear brake pads M3 | : | 34 21 1 157 042
Rear brake sensor | : | 34 35 1 180 782

### Torques:

Caliper slide bolts | : | 30 Nm (22 ft lbs.)

E30 M3 Repair Manual V2.7. Copyright ©1999-2001 Koala Motorsport & Brett Anderson