Note: Before starting work, please read the Note at the beginning Chapter 23 regarding the hazards of asbestos dust.
1. Place the car on a level surface, apply the handbrake and select reverse gear first (Manual Transmission) or "R" (automatic transmission). Block the front wheels. Loosen the wheel nuts, jack up the rear of the car, and secure it on jack stands. Remove the wheel and release the handbrake completely.
2. Unscrew the bolt from the handbrake cable fastening to the caliper, and disconnect the cable from the lever.
3. To minimize fluid loss, either remove the master cylinder reservoir cap and use a flexible hose to drain the brake fluid.
4. Clean the area around the connection, and unscrew the flexible hose connection box bolt. Remove the two seal gaskets.
5. Loosen both caliper guide pin bolts (use a thin double-sided wrench), unscrew the rear guide pin bolt, and rotate the caliper body upward. Remove the brake pads, shims, and anti-rattle springs.
6. Unscrew the bolted front guide pin and disconnect the caliper body from the unit suspension. Remove the guide pins, if necessary, by screwing them into their bolts. Remove the rubber dust cap from each guide pin, and the rubber bushings that are used on the front guide pin on some models. Unscrew the mounting hanger bolt from the trunnion connecting plate.
7. Clean the components to remove all dust.
8. Using long pliers inserted into the notches on the piston, unscrew the piston counterclockwise. Remove it from the caliper housing and from the dust seal.
9. Remove the retaining ring "A" (Pic. 9.24). Then remove the first spacer, raised spacer, second spacer, ball bearing and mounting nut. Remove the cylinder using a lever, locking the installation nut.
Pic. 9.24. Removing retaining ring 'A' from piston
10. Using pliers, remove the retaining ring from the inner diameter of the caliper cylinder "IN" using a suitable length of tube to compress the spring cap. Then remove the retaining ring, spring cap, spring and spring seat.
11. Use pliers to remove the retaining ring "WITH", then disconnect the plate, pusher and plunger. Remove the O-ring seal using a lever.
12. If using a blunt tool such as a knitting needle, remove the piston seal from the caliper.
13. Disconnect the return spring from the handbrake lever, then use a lever to remove the lever and cam assembly from the caliper body. The short rod and pusher must first be removed.
14. Clamp the cam with soft material, unscrew the lock nut, and remove the grower, return spring, lever and dust cap from the cam.
15. Clean all components completely using only methyl alcohol or clean brake fluid. Never use mineral solvents such as gasoline or paraffin, which will attack the rubber components of the brake system.
16. Remove all insulation, gaskets, dust caps and other rubber components. They should be replaced as a matter of course every time. when disassembly takes place. Don't try to save money by reusing these components.
17. Examine all components of the caliper assembly, looking for signs of wear or damage. In particular, the bore diameter of the cylinder and piston must match and show no signs of scratches, corrosion or wear. If there is uncertainty regarding the condition of a caliper part, it must be replaced, and the replacement must be carried out only as a cylinder/piston pair.
18. The manufacturer declares; that minor scratches. rust, etc. you can polish it to the diameter of the cylinder bore using fine-grained sandpaper, but the piston cannot be polished, only replaced. The piston surface is coated with metal and should not be polished with corundum or similar abrasives.
19. Check the condition of the caliper housing and suspension. Check the guide pins. Use compressed air for cleaning.
20. When assembling, make sure that all parts are clean and dry.
21. Place a new dust cap on the cam and position the lever correctly on the cam washers, then install the return spring, bushing and nut. Tighten the nut securely, but do not overtighten it. Apply silicone lubricant - or RVS (Paly Butyl Cuprysil) high temperature lubricant for the brake system. Check that the assembly is installed correctly and the lever rotates. Install the upper return spring.
22. Saturate the new piston seal with clean brake fluid and use only your fingers when seating it in the cylinder bore diameter.
23. Place a new pushrod O-ring on the plunger and pushrod. Assemble the plunger and pusher and place them on the caliper body. Install the plate so that the pushrod fits the concave depression in the caliper body, then secure the assembly with a retaining ring in place "WITH". See Fig. 9.25 and 9.26.
Pic. 9.25. Proper alignment of the locking plate with the caliper body
Pic. 9.26. Installing the locking plate and pushrod parts into the caliper body
24. Install the spring seat, spring and spring cap, then clamp the spring cap using a suitable length of tube (Pic. 9.27), until the retaining ring "IN" will not fit into place to secure the assembly. Check the retaining ring to ensure it fits completely into the groove.
Pic. 9.27. Installing the spring seat, spring and spring cap into the caliper body
25. Install the new seal, spring and spring cap using only your fingers (Pic. 9.28). Lubricate the seal lips and where the mounting nut fits into the piston. Install the retaining ring "A".
Pic. 9.28. Correct installation of the cuff on the fastening nut
26. Apply rubber lubricant to the inner and outer lips of the new dust seal and seat it on the piston. Lubricate the piston and caliper cylinder diameter with clean brake fluid, then install the piston assembly and screw it clockwise until it stops. Place the dust seal on the caliper body.
27. Install the caliper mounting hanger onto the connecting plate of the steering axle, and tighten the mounting bolts with the tightening torque specified in the Specifications. Place a new rubber dust cap on each guide pin (don't forget to seat the new rubber bushing against the front guide pin where it is used) and lubricate with silicone compound - or RVS (Paly Butyl Cuprysil) high temperature lubricant. Install the brake pads as described above.
28. Place the caliper body on the suspension and install the brake pads, install the guide pin bolts, and tighten them according to the torque wrench marks specified in the Specifications.
29. Make sure that the flexible hose is installed correctly and is not kinked. Use new gaskets and bolt all connections to the torque specified in Specifications.
30. If necessary, bleed the system to remove air from the system as described above. Check the fluid level in the master cylinder reservoir.
31. Connect the handbrake cable to the lever, and bolt it to the caliper body, making sure the pins are positioned correctly. Apply the handbrake until the correct clearance between the shoes and the drum is established.
32. With another person pressing the brake pedal, check the caliper assembly for signs of leaks. Wash out any fluid leaks and install the wheel. Lower the vehicle to the ground and tighten the wheel nuts to the specified torque Specifications.
33. Repeat the complete procedure on the opposite caliper. Always replace both calipers together to ensure even braking.