Removing
Note. Brake discs cannot be sanded. If there is significant wear or deep scratches, replace the discs.
Note. When replacing brake discs, replace them complete with brake pads.
Place the car on a two post lift.
Unlock the steering wheel.
Remove the front wheels.
Pic. 6.66. Removing the fastening of the guide pads: 1 - fastening bolts
Remove the two bolts securing the guide pads (pic. 6.66).
Hang the brake caliper assembly from the shoe guide.
Measuring the thickness of the brake disc
Install a micrometer to measure the thickness of the brake disc (pic. 6.67).
Pic. 6.67. Installing a micrometer to measure the thickness of the brake disc: 1 - micrometer
Pic. 6.68. Measurement points for brake disc thickness
Measure the thickness of the brake disc in order at four points shown in Figure 6.68, around the circumference (through 90°).
Standard front brake disc thickness: 22mm (vehicles with K4J engine) and 24 mm (vehicles with K4M, F4R engines).
If the thickness is less than specified, replace the discs.
Remove the shoe guide.
Pic. 6.69. Removing the brake disc mount: 1 - fastening bolts
Loosen the two brake disc screws (pic. 6.69).
Remove the brake disc.
Examination
Check for corrosion, wear and damage on the inner walls of the cylinder. Replace cylinder body if necessary. Minor imperfections caused by corrosion or foreign particles can be removed by sanding the surface with fine emery cloth. Check for corrosion, wear and damage on the surface of the piston, on the guide pin and its boot, and on the surface of the brake disc. If necessary, replace the corresponding component.
Installation
Clean the shoe guides and brackets.
Installation is made in an order, the return to removal.
Torque tighten:
- brake disc screws (15 Nm);
- guide rail mounting bolts (105 Nm).
Apply FRENEBLOC to the threads of the guide shoe mounting bolts before installation (or its equivalent).
Install wheels.
Torque tighten the wheel bolts to 105 Nm.