Contents: Disassembly and assembly ↓ Checking the details ↓ Checking the brake disc runout ↓ Replacing brake pads ↓
Disassembly and assembly
Disconnect tube 5 (see fig. 144) and remove the dust caps 2 from the cylinders. Then, by forcing a stream of compressed air through the inlet for the brake fluid, push the pistons 1 out of the cylinders on the caliper 4 and remove the sealing rings 3 from the cylinders.
During long-term operation of the car, corrosion of the working cylinders occurs. In this case, as well as in case of wear or damage to the working surfaces of the cylinder or piston, the cylinder is replaced as an assembly. To do this, after performing the above operations, clamp the caliper in a vice, sink the clamps and knock the cylinder out of the caliper grooves with a rubber hammer. Then install a new cylinder in the grooves.
The brake mechanism is assembled in the reverse order. In this case, the sealing rings, pistons, and cylinder mirrors are lubricated with brake fluid.
Checking the details
Carefully check all parts, having previously washed them with warm water and detergent and dried with a jet of compressed air. If traces of wear or seizure are found on the piston or cylinder mirror, replace the cylinder complete with pistons. In all cases, when the piston is removed from the cylinder, it is recommended to replace the sealing ring in the cylinder groove and the dust cap.
(The original source is located on the website: «vazbook»)
Checking the brake disc runout
The axial runout of the brake disc 1 (Fig. 145) is checked without removing it from the vehicle. The maximum permissible runout according to indicator 2 is 0.15 mm (the indicator is installed using a magnetic stand 3). If the runout is greater, grind the disc using mandrel 67.7141.9500. Then grind it, but the final thickness of the disc should not be less than 9.5 mm. In case of damage or very deep scratches, as well as in case of wear exceeding 0.5 on each side, replace the disc with a new one. In this case, the brake disc must be changed only when compatible with the front wheel bearing hub, since its final processing is carried out in assembly with the hub. Removal and installation of the hub with the brake disc are described in Section "Front suspension, wheels, tires".
Replacing brake pads
The pads are replaced with new ones if the thickness of the linings has decreased to 1.5 mm. To replace the pads, remove the cotter pins 14 (see fig. 143) and pins 8 with springs. Then remove shoes 16 and springs 15. Carefully, so as not to damage the dust caps and prevent fluid from splashing out of the hydraulic drive reservoir, push the pistons into the cylinders. Install new shoes, then pins, springs and cotter pins, having previously applied a thin layer of some kind of consistent grease to the surface of the pins.