To check and renew brake pads, raise the front of the car and support it securely on jackstands. Remove the front wheels. Check the thickness of the brake pad lining using the inspection hole in the caliper body. If any pad is below specification minimum or contaminated, renew the pads in complete set and rectify contamination prior to installation. To prevent the master cylinder reservoir from overflowing when pushing back the caliper pistons, drain about two-thirds of the brake fluid. Carry out this job on one caliper at a time and renew the brake pads in sets of four. Take out the lower caliper guide pin and turn caliper upwards to expose the pads, shims and anti rattle clips. Remove disc pads noting the position of the wear indicators and anti squeal shims. If the guide pins feel tight or wear is uneven, clean and lubricate them for free movement. Insert hammer handle and push the piston back into the caliper. If there are leaks or any deterioration, consider having the caliper overhauled. Each inner pad must be fitted with a pad wear indicator, the anti-squeal shims cleaned and the anti-rattle clips properly seated before placing the pads on the anchor plate. Drop the caliper, put the lower guide pin in place and pump the brake pedal so that the pads fit alongside the Brake Rotor. If needed, top up with fluid, replace front wheels, lower vehicle, and road-test to check operation of brakes. To overhaul the caliper, lift the front of the vehicle, detach the banjo bolt and brake hose, and discard the washers. Take out the guide pins and remove the caliper. The dust boot can then be removed followed by forcing the piston from the caliper bore using compressed air or by pushing the brake pedal. Take off the piston seal. Clean all parts. Check for wear. Apply clean brake fluid to the piston and seal. Then fit the new seal and piston. Reattach the caliper, applying a correct torque on the guide pins and brake hose with sealing washers. You need Bleed the hydraulic system, install the wheel, lower the vehicle. To check the Brake Rotor, lift the front of the vehicle, then remove the wheel, and caliper with pads. The disc must be checked for scores, cracks, and wear. If scored, it must be machined. Examine the runout utilizing a dial gauge and, where required, modify the position of the disc or replace it. Take readings of the disc thickness at eight points, and renew if below specifications. Lift the vehicle and remove the wheel, caliper, and pads before removing and installing the anchor plate. Make a mark on the disc after removing it so you can put it back. Never use a hammer. During installation, be sure the mating faces are clean, torque the anchor plate bolts and refit the brake pads/caliper.