Attention! When replacing the brake discs, the brake pads must also be changed at the same time.
In the workshop, the brake disc can be checked for runout. The permissible lateral runout of the installed brake disc must not exceed 0.07 mm at the measuring point 2 mm from the outer edge of the disc surface.
Removing
Front wheel brakes
1. Mark the position of the front wheels on the hub with paint. This will allow the assembly to set the balanced wheel in its original position.
2. Loosen the wheel bolts. The vehicle must be on wheels during this operation.
3. Place the vehicle on jack stands and remove the front wheels.
4. Unscrew the fastening bolts A of the shoe guide and remove the guide together with the caliper (see illustration).
4.4 Unscrew the mounting bolts A of the shoe guide and remove the guide together with the caliper
5. Attach the caliper to the body with a wire hook made by yourself. The brake hose must not be kinked or stretched.
Attention! Do not disconnect the brake hose of the wheel brake cylinder from the caliper, because after installation the brake system will have to be pumped.
If the caliper needs to be completely disconnected, the brake fluid supply hose for the clutch drive must first be disconnected. Otherwise, the brake hose cannot be detached from the caliper.
Attention! This will leak brake fluid. Collect the escaping liquid in a container designed for this purpose.
Attention! In case of damage to the walls of the wheel cylinder, the caliper must be replaced as a set. In this case, the brake hose must also be replaced.
6. Unscrew bolts B securing the brake disc to the hub using a T40 screwdriver for socket head cap screws (TORX) (see illustration).
4.6 Unscrew the bolts B fastening the brake disc on the hub using a T40 screwdriver
7. Remove the brake disc.
Installation
To ensure uniform braking of both wheels, both brake discs must have the same ground surfaces with the same degree of roughness. Therefore, be sure to replace both brake discs of one axle at the same time.
8. Measure the brake disc thickness.
9. Remove the protective lacquer coating from the new brake discs with a nitro thinner.
10. Install the brake disc onto the front wheel hub and secure with two Allen head bolts. Bolt tightening torque 25 Nm.
11. Establish a support, without allowing at the same time twisting and a tension of a brake hose. Check up absence of a tension of a hose and its free wheeling by rotation of a steering wheel from an emphasis against the stop.
12. Fasten the caliper with new bolts with a tightening torque of 100 Nm. Apply a protective lubricant such as LOCTITE FRENBLOC to the bolt threads before installing the bolts.
Attention! If the brake hose was disconnected from the caliper, then connect it without allowing it to twist.
13. Install the brake pads.
14. Remove air from the brake system, if it was opened, see the relevant chapter.
15. Install the wheels in accordance with the labels applied during removal and screw in the wheel bolts.
16. Lower the car. Tighten the bolts in a cross pattern to 90 Nm.
Attention! Depress the brake pedal several times until a strong resistance is felt.
17. Check up level of a brake liquid in a broad tank. If necessary, top up to the maximum mark.
Attention! Make sure that
- A) brake hoses are securely connected;
- b) the brake hose is fixed in the holder;
- V) fittings for bleeding the brake actuator are wrapped;
- G) there is enough brake fluid in the expansion tank.
18. Carry out a leak test of the brake system with the engine running.
To do this, depress the brake pedal with a force of 200-300 N (20-30 kg) for approximately 10 seconds. The pressure in the system and, accordingly, on the brake pedal, must not fall. Check all connections for tightness.
19. Carefully run in new brake pads. To do this, slow down several times, bringing the speed from about 80 km / h to 40 km / h and lightly pressing the brake pedal. Let the brakes cool down in between.