Concerns about changing the pads on an ABS-equipped vehicle include damage to the modulator valve assembly due to debris in the system, air trapped in the system due to improper bleeding and air being inadvertently introduced into the system when the pump motor pressurises the accumulator after pad replacement. These problems can be avoided by following proper procedures. The service manual specific to the vehicle should always be consulted before beginning work to identify bleeding sequences and procedures.
Things you need
Metric wrench set
Safely raise the vehicle, with a floor jack, and place a jack stand under the frame. Lower the vehicle onto the jack stand so that the floor jack is not supporting the weight of the vehicle. Remove the wheel and store the lug nuts, along with the wheel, in a secure place to prevent loss of lug nuts and tripping hazards.
Remove the caliper bolts from the caliper, and lift the caliper off the mounting bracket. Remove the pads from the bracket, and save any clips or shims that are on the old pad set for use on the new pad set. These clips and shims are critical for quiet brake operation; do not discard them unless replacements are available.
Open the bleeder screw, and compress the caliper piston back into the piston bore in the caliper housing. Allow any fluid that is displaced to run into the drain pan, and close the bleeder screw when the piston is fully compressed. Doing this will prevent any debris trapped in the caliper bore from being sent through the ABS system's modulator valve assembly.
Install the clips and shims from the old pads onto the new set, and install the new pads onto the bracket. Install the caliper over the pads, and bolt it securely to the caliper bracket.
Top off the master cylinder with new fluid, and turn the key to the run position without starting the vehicle. This will allow vehicles that are equipped with pump motors to pressurise the system without draining the master cylinder completely. Pump the brake pedal several times to expand the caliper pistons in their bore.
Reinstall the wheel and lower the vehicle to the ground. Start the engine and test drive to verify the repair. If the system needs to be bled, consult the service manual for the proper sequence and any special procedures.
Things you need
- Floor jack
- Jack stands
- Brake fluid
- Brake pads
- Metric wrench set
- Service manual