Front brake pads - renewal

Braking system / Front brake pads - renewal

Warning: Renew BOTH sets of brake pads at the same time - NEVER renew the pads on only one wheel, as uneven braking may result. Note that the dust created by wear of the pads may contain asbestos, which is a health hazard. Never blow it out with compressed air, and DO NOT inhale any of it. An approved filtering mask should be worn when working on the brakes. DO NOT use petrol or petroleumbased solvents to clean brake parts; use brake cleaner or methylated spirit only.

1 Apply the handbrake, then jack up the front of the vehicle and support it on axle stands (see “Jacking and vehicle support”). Remove the front wheels.

2 Trace the brake pad wear sensor wiring (where fitted) back from the pads, and disconnect it from the wiring connector. Note the routing of the wiring, and free it from any relevant retaining clips.

3 Where necessary to improve access, undo the retaining bolts and remove the air deflector shield from the caliper.

4 Using an Allen key, slacken and remove the two caliper mounting bolts, then lift the caliper away from the brake pads and hub, and tie it to the suspension strut using a suitable piece of wire (see illustrations). Do not allow the caliper to hang unsupported on the flexible brake hose.

4.4a Undo the caliper mounting bolts using an Allen key

4.4b Removing the caliper mounting bolts

4.4c Lifting the caliper from the front brake pads

5 Withdraw the two brake pads from the carrier bracket and recover the anti-rattle springs, noting their correct fitted locations (see illustration). Note that the springs are different and are not interchangeable.

4.5 Removing the front brake pads

6 First measure the thickness of each brake pad (including the backing plate). If either pad is worn at any point to the specified minimum thickness or less, all four pads must be renewed. Also, the pads should be renewed if any are fouled with oil or grease as there is no satisfactory way of degreasing friction material, once contaminated. If any of the brake pads are worn unevenly, or are fouled with oil or grease, trace and rectify the cause before reassembly. New brake pad kits are available from WV dealers.

7 If the brake pads are still serviceable, carefully clean them using a clean, fine wire brush or similar, paying particular attention to the sides and back of the metal backing.

Clean out the grooves in the friction material (where applicable), and pick out any large embedded particles of dirt or debris. Carefully clean the pad locations in the caliper body/mounting bracket.

8 Prior to fitting the pads, check that the spacers/sleeves are free to slide easily in the caliper body bushes, and are a reasonable tight fit. Brush the dust and dirt from the caliper and piston, but do not inhale it, as it is injurious to health. Inspect the dust seal around the piston for damage, and the piston for evidence of fluid leaks, corrosion or damage. If attention to any of these components is necessary, refer to Section 8.

9 If new brake pads are to be fitted, the caliper piston must be pushed back into the cylinder to make room for them. Either use a G-clamp or similar tool, or use suitable pieces of wood as levers. Provided that the master cylinder reservoir has not been overfilled with hydraulic fluid, there should be no spillage, but keep a careful watch on the fluid level while retracting the piston. If necessary, the surplus should be syphoned off or ejected through a plastic tube connected to the bleed screw (see Section 2). Note: Do not syphon the fluid by mouth, as it is poisonous; use a syringe or an old poultry baster.

10 Fit the new anti-rattle springs to the carrier bracket, making sure they are correctly positioned and fit the pads, and ensuring that the friction material of each pad is against the brake disc. Note that, where necessary, the pad with the wear sensor wire should be installed as the inner pad (see illustrations).

4.10a Fit the anti-rattle springs to the carrier bracket, making sure they are correctly located . . .

4.10b . . . and install the brake pads with their friction material facing the disc

11 Position the caliper over the pads, and pass the pad warning sensor wiring (where fitted) through the caliper aperture.

12 Press the caliper into position sufficiently until it is possible to install the caliper mounting bolts. Note: Do not exert excess pressure on the caliper in either direction, as this will deform the pad springs, resulting in noisy operation of the brakes. Tighten the mounting bolts to the specified torque setting.

13 Reconnect the brake pad wear sensor wiring connectors, ensuring that the wiring is correctly routed. Where necessary, refit the air deflector shield to the caliper.

14 Depress the brake pedal repeatedly, until the pads are pressed into firm contact with the brake disc, and normal (non-assisted) pedal pressure is restored.

15 Repeat the above procedure on the remaining front brake caliper.

16 Refit the roadwheels, then lower the vehicle to the ground and tighten the roadwheel bolts to the specified torque.

17 New pads will not give full braking efficiency until they have bedded-in. Be prepared for this, and avoid hard braking as far as possible for the first hundred miles or so after pad renewal.