Front wheel brake mechanism: 1 - brake hose; 2 - air release valve; 3 - caliper guide pin (covered with a protective cover); 4 - shoe guide; 5 - brake caliper; 6 - brake disc; 7 - brake pads
Tightening torques:
- Wheel bolt - 90 Nm
- Caliper guide bolt - 40 Nm
Attention! Replace brake pads only in pairs on both wheels at the same time with pads of the specified brands.
New brake pads are run in after 180–230 km, during which time the efficiency of the brakes is somewhat reduced. During the running in process of the pads, sharp and prolonged braking to a complete stop is not recommended.
To speed up the process of running in new pads to the disc, it is recommended to brake the car several times from a speed of 80 to 40 km/h, carefully pressing the brake pedal. Between such braking, maintain a time interval until the brake mechanism has completely cooled down.
Figure 7.1. Turning out the guide pins on the front wheel brake mechanism: 1 – guide pin; 2 – protective cover
Removal
- raise the front of the car and place supports under the body;
- remove the wheel from the desired side;
- disconnect the brake pad wear sensor connector;
- pull the caliper towards you, thus moving the piston inside the brake cylinder;
- unscrew the guide pin bolts with two wrenches, do not clean the guide pins;
- remove the brake guide bracket and tie it away from the work area without pulling on the brake hose;
- remove the brake pads;
- inspect the brake pads: compare the thickness of the pads with the minimum permissible value, the friction lining should wear evenly, without distortion. In case of oiling, the friction lining is subject to unconditional rejection, since it is impossible to remove the oil that has soaked the lining. Eliminate the cause of oil getting into the brake mechanism. In case of replacing one pad, all four on both wheels should be replaced;
- to decide whether the brake pads are suitable, clean them with a wire brush, paying attention to the cleanliness of the friction lining grooves. Clean the pad seats in the guide bracket and caliper. The guide pins should move easily in the caliper bushings, inspect the protective boots of the guide pins and make sure they are intact;
- check the integrity of the brake cylinder piston dust boot. Make sure that there is no fluid leakage in the piston-cylinder pair;
- make sure that the brake disc does not have stepped, uneven wear and that its thickness does not exceed the permissible values;
Figure 7.2. Pressing the piston into the caliper using the Fre. 823 device
Figure 7.5. Installing anti-squeak springs (insert)
- install brake pads and anti-squeal springs into the caliper (see Figure 7.5). When installing new pads, the piston must be pressed into the caliper flush with its surface. For this purpose, use the Fre. 823 device (Figure 7.2). If you don't have a device, you can use a clamp or suitable wooden blocks as levers. Do not allow the expansion tank to overflow - remove excess fluid in time using a syringe or rubber bulb. The pads are installed with the friction linings facing the brake disc. The pad with the wear sensor is installed on the inside;
- install the brake guide bracket and lower guide pin in place, after applying Loctite Frenbloc to the threads;
- press the brake caliper and install the upper guide pin, after applying Loctite Frenbloc to the threads;
- tighten the guide pins with new bolts to the specified torque, starting with the bottom pin;
- connect the contact connector to the brake pad wear sensor, correctly laying the wiring;
- press the brake pedal several times to bring the piston into working position;
- repeat all the above operations for the brake mechanism of the other wheel;
- lower the vehicle and check the fluid level in the expansion tank.
[Original article is on the portal: www.renaultbook.ru]