1. Remove the cover plates, where present.
2. Disassemble the safety devices such as retainer pins, clamping sleeves, springs or screws used to secure the brake pads.
3. Disconnect the wear indicator connector, where present.
WARNING! Avoid any leaks of the brake fluid in the fluid reservoir and drain some if necessary. If inappropriately handled, brake fluid may cause serious injury or damage. Observe the brake fluid manufacturer’s instructions scrupulously.
4. Use an expansion tool to push the pads backward, if necessary.
5. With fixed calipers, pull the pads out of the caliper body.
6. With floating calipers, start by disassembling the brake pads on the piston side, then shift the sliding caliper until the other pads can be removed from the pin (where relevant).
7. Remove any shims and replace with new ones if damaged. Do not disassemble any accessories secured to the brake piston. These must be repaired professionally by an authorized workshop only, according to the vehicle manufacturer’s instructions.
b) Pad replacement with partial disassembly of the caliper: for fist caliper. If pad removal from the top is not possible, see Fig. 3.
1. If a wear indicator is provided, disconnect the connector.
2. Depending on the caliper configuration, disassemble locking springs, fastening screws, guiding pieces or bolts.
WARNING! Avoid any leaks of the brake fluid in the fluid reservoir and drain some if necessary. If inappropriately handled, brake fluid may cause serious injury or damage. Observe the brake fluid manufacturer’s instructions scrupulously.
3. Push the piston back and pivot out or remove the caliper body. Do not detach the brake tubes.
4. Support or suspend the removed caliper body in such a way that the brake tubes are not stretched or damaged.
5. Remove the brake pads from the caliper body or stirrup.
Subsequent steps
1. To make the new brake pads fit into the caliper, push the piston back.
2. With 4-piston fixed calipers or 2-piston fist calipers, insert shims to prevent pistons from coming back out while the other pistons are pushed back.
3. With calipers which combine a mechanical parking brake and brake clearance adjustment feature, the piston must be brought back to its original position by turning it or by means of an adjustment screw, depending on the type of caliper.
4. Clean the stirrup, caliper body and guides with non-mineral-oil based cleaning agents. Replace damaged or brittle dust caps.
CAUTION! Do not clean components of the braking system with compressed air, a stiff brush or similar. Do not raise fine dust which, if inhaled, can be harmful to health. Wear a respirator, if working in a poorly ventilated area. Do not degrease guides and caliper spring assemblies, as they require special grease. When the caliper has difficulty sliding, slightly grease the sliding surfaces with special grease according to the instructions provided by the vehicle or caliper manufacturer. The friction materials of the brake pads and s must not come into contact with the greases used, as this could lead to brake failure; if this should happen, degrease the rotors and use new brake pads. Replace corroded guides.
5. With stepped pistons, check the correct position using dedicated piston gauges and readjust, if necessary.
6. Check brake rotor thickness and replace all rotors on an axle if the wear limit is exceeded or if heavy surface crazing or cracks are found.
7. Remove any corroded areas on the outer and inner parts of the rotor braking surface.
Fitting procedure
1. The new brake pads must move freely in their guides.
2. The contact surfaces of the pad metal backing plate/caliper guides as well as of the pad metal backing plate/brake pistons are to be slightly greased with a special grease according to the vehicle manufacturer’s instructions.
3. Shims which are not corroded, bent or embedded may be reinstalled.
4. If the wear indicator is envisaged, reconnect the new sensor or the existing one if it is not damaged.
5. Insert the new brake pads in the reverse order as described under “Replacement”, with the friction surface pointing towards the brake rotor. With asymmetrical brake pads, the arrow must point in the direction of rotation of the rotor (in forward gear).
6. Insert locating pins, springs and clamping sleeves in their original position before being disassembled.
7. If the brake pads are equipped with wear indicators, re-connect plugs and sockets.
8. Tighten the fastening screws or guiding pins. Replace self-locking screws with new ones of the same type.
WARNING! Observe the tightening torque recommended by the vehicle manufacturer. An incorrect tightening torque may induce braking system failure.
9. Brakes combined with a mechanical parking brake clearance adjustment feature must have free travel after repeated brake actuations. Follow the instructions provided by the vehicle manufacturer.
10. Replace the pads on the other end of an axle in the same way.
Functional test
Once you have re-fitted the wheels and lowered the vehicle, be sure to observe the following points:
1. Check the brake fluid level in the reservoir and replenish to maximum filling line, if necessary. Use only new brake fluid of the grade specified for the particular vehicle type.
WARNING! If inappropriately handled, brake fluid may cause serious injury or damage. Observe the brake fluid manufacturer’s instructions.
CAUTION! To re-position the brake pads correctly, repeatedly operate the brake once the vehicle is back on the ground.
Repeat this process until the brake pedal travel has stabilised at approx. one-third of its total travel. At a constant maximum pedal force, the pedal travel must not change even over a prolonged period of application.
CAUTION! If the pressure point and consistency cannot be achieved, recheck the entire braking system, as otherwise the risk of a brake failure cannot be ruled out.
Recheck the braking system for leaks.
2. Recheck the brake fluid level and replenish up to the maximum filling line, if necessary. Use only new brake fluid of the grade specified for the particular vehicle type.
WARNING! If inappropriately handled, brake fluid may cause serious injury or damage. Observe the brake fluid manufacturer’s instructions. Perform trial brake applications at low speeds keeping in mind that brake effectiveness may be somewhat reduced during the first brake applications. Do not apply excessive force or perform continuous brake applications in order to achieve faster brake rotor pad running-in.
3. Always observe the running in instructions provided by the vehicle manufacturer.
4. Observe traffic regulations when performing brake tests.
5. Carry out a functional test on a rolling road to ascertain that the system meets any legal requirements.