| 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. |
|
