Attention! The replacement of the shoes must be carried out simultaneously on both brake mechanisms. See also the warning at the beginning Removal, repair and installation of disc brake calipers!
Note. Simultaneously with the replacement of the brake shoes, their coupling and guide springs should also be replaced, which, as a result of constant cyclic mechanical and thermal loads, stretch / sag over time, stopping developing the required force, which leads to sticking of the brakes and accelerated wear of the drums.
Rear wheel drum brake components
1 - Shield of the brake mechanism; 2 - Wheel cylinder; 3 - Expanding bar fork; 4 - Adjusting bolt; 5 - Expanding bar fork; 6 - Upper coupling spring; 7 - Automatic regulator lever; 8 - Spring of the automatic regulator; 9 - Lower coupling spring; 10 - Guide spring; 11 - Brake shoe; 12 - Executive lever of the parking brake; 13 - Parking brake cable; 14 - Wheel bearing cap; 15 - Pin retainer; 16 - Washer of the rear axle spindle; 17 - Anchor pin; 18 - Cotter pin; 19 - Spindle nut; 20 - Brake drum
1. Loosen rear wheel nuts. Jack up the back of the car and place it on jack stands. Support the front wheels with wheel chocks. Remove the rear wheels and release the parking brake.
2a. The design of the drum brake mechanism is shown in the illustration above. Remove the brake drum from the hub. The drum should be removed freely enough, but in case of difficulty, gently tap it with a soft-faced hammer, or screw a pair of M8 bolts into the threaded holes (see accompanying illustration).
3. It is easier to replace the shoes after removing the axle of the hub assembly from the trunnion (remove the wheel bearing cap, give the spindle nut and remove the washer (see chapter Suspension and steering).
4a. Follow the instructions below to check the condition of the components and replace the brake shoes. Act strictly in the specified order. Remember that all four shoes of both brakes must be replaced at the same time.
4b. Before dismantling the components, wash them with a special cleaner, then dry them (NEVER BLOW BRAKE DUST WITH COMPRESSED AIR!).
4s. Using a screwdriver, press the guide spring down, then turn the anchor pin with the lock parallel to the groove in the spring - the latter should bounce off the shoe.
4d. Remove the shoe assembly from the brake shield (hub removed for clarity).
4e. Disconnect the return spring.
4f. Pull back the spring on the parking brake cable just enough to allow the side cutters to grab onto the cable while holding the spring compressed (try not to cut your torso); Now disconnect the end of the cable from the parking brake actuating lever.
4g. Rotate the parking brake actuating lever away from the rear brake shoe until the yoke of the expander adjusting bolt should disengage from its seating groove in the shoe to allow the shoes to disengage.
4h. Remove the auto adjuster lever and spring from the front brake shoe.
4i. Remove the retainer and disconnect the parking brake lever from the rear shoe (do not lose the bent washer installed under the retaining ring).
4j. Connect the new rear shoe to the lever (don't forget to put a bent washer under the latch); Use needle nose pliers to squeeze the ends of the retainer together.
4k. Clean the adjusting bolt and spreader forks, then lubricate them with high-temperature grease.
4l. Hook the auto adjuster spring into the hole in the new front shoe, then tuck the lever pin into the other designated hole in the shoe.
4m. Insert the short fork of the expander bar into its groove in the front shoe (make sure that the fork is correctly engaged with the automatic regulator lever.
4n. Connect the upper return spring to both brake shoes, spread the lower ends of the shoes and insert the fork of the expander bar into the groove in the rear shoe (check the correct location of the stepped protrusion of the fork).
4o. Lubricate the surfaces of the brake shield in contact with the shoes with refractory grease.
4r. Using side cutters, compress the parking brake cable spring (do not cut the cable) and, holding it in this position, connect the tip of the cable to the actuating lever.
4q. Install the shoe assembly on the brake shield, placing the upper ends of the shoes in the grooves in the pistons of the wheel cylinder; connect the lower return spring to the shoes.
4r. Pass the anchor pins through the holes in the brake shield and shoes, install the guide springs; unfold your fingers, fixing the springs; make sure that the parking brake cable spring and the lower coupling spring are wound under the anchor bracket strips, as shown in the picture.
5. Before installing the drum, check it for nicks, gouges, overheating, and other defects. If serious damage is detected, the traces of which cannot be eliminated by treating the drum with fine-grained sandpaper, the drum should be given to the groove (in compliance with the maximum allowable repair diameter). If the reaming of the drum cannot be done without violating the requirements for the maximum allowable inner diameter (stamped on the drum - see accompanying illustration), you will have to replace it. If turning the drums is not possible, at least carefully clean their working surfaces with fine-grained sandpaper.
Note. The compilers of this Guide recommend turning drums, regardless of their condition, in order to remove all kinds of defects and eliminate ovality.
6. Reinstall the hub assembly with wheel bearing, put on the washer and screw on the new spindle nut, tightening it to the required torque (see Specifications to the head Suspension and steering).
7. Replace the wheel, then lower the vehicle to the ground and tighten the wheel nuts to the required torque (see Specifications to the head Current service).
8. Brake the vehicle several times while driving both forward and reverse in order to automatically adjust the brake mechanisms.
9. Before starting the operation of the car, make sure that the brakes are working properly.