Attention: when replacing the pads, change the return and support springs - over time, under the influence of multiple heating / cooling cycles, they lose their original qualities.
1. Loosen the wheel nuts, raise the rear of the car. place it on stands. Block the front wheels. Remove the rear wheels and release the parking brake.
2. Remove the brake drum. If the drum does not come off, lightly tap it and screw a couple of M8 bolts into the special threaded holes. If the drum is not removed in this case, then the pads have made rather deep grooves in the drum. Remove the rubber plug in the platter and use a screwdriver to turn the adjustment nuts on the automatic adjustment mechanism until the drum is removed.
Pic. 5.2 Using M8 bolts to remove the brake drum
3. When replacing the pads, you can inspect the bearing assembly: remove the cover, unscrew the nut and remove the hub.
Pic. 5.3 Assembling the hub and bearing assembly
4. Following figures from 5.4a to 5.4p, replace the pads. You should replace all the pads at once, but still work on each wheel in turn.
Pic. 5.4a Assembly of a typical drum brake assembly
Pic. 5.4b Pull the spring holder with a screwdriver, then turn the tensioner finger until its head matches the slot in the holder - the spring should make a characteristic sound when the tensioner is compressed (repeat with another spring)
Pic. 5.4c Remove shoe assembly
Pic. 5.4d Using a suitable tool, remove the parking brake cable spring, unfasten the cable from the parking brake lever
Pic. 5.4e Lay the pads on a clean surface. Unfasten the lower return spring from the shoes
Pic. 5.4g Remove the self-adjusting lever and its spring from the drive shoe
Pic. 5.4e While jiggling the parking brake lever, release the adjusting bolt earring from its groove on the driven shoe. Disconnect pads
Pic. 5.4h Remove the retaining ring and dismantle the parking brake lever
Pic. 5.4i Install the parking brake lever on the new block. Squeeze the ends of the lock washer
Pic. 5.4k Put the spring of the self-adjusting mechanism on the lever and the driven shoe, insert the lever stick into the hole in the shoe
Pic. 5.4 l Insert the short eyelet of the adjusting bolt into the slot of the drive shoe with the catch of the self-adjustment lever
Pic. 5.4m Put on both pads the upper return spring, insert the second earring of the adjusting bolt into the slot of the pad
Pic. 5.4n Bring the lower ends of the shoes together and install the lower return spring
Pic. 5.4o Lubricate the contact points of the pads with the platter with refractory grease
Pic. 5.4p Compress the parking brake cable spring and connect the cable to the lever
Pic. 5.4r Install the pads on the platter. Watch for the coincidence of the slots in the brake cylinder and the protrusion of the pads
Pic. 5.4c Pass the tensioner pins through the holes in the platter, install the spring retainer (see fig. 5.4c), make sure that the parking brake cable spring and lower return spring remain behind the locking bracket as shown in the illustration
5. Before installing the drum, inspect it for cracks, chips, deep nicks, and corrosion. If corrosion cavities cannot be removed with sandpaper, as well as other defects, the surface of the drum must be restored by boring.
Pic. 5.5 Marking the maximum inside diameter of the drum
Note: The drum bore must not exceed the maximum size of the brake drum. This diameter is stamped on the rim of the drum. If you think that boring is not required, smooth out the largest surface defects with sandpaper.
6. Install hub and vacuum unit, washer and new nut (if these parts were removed). Tighten the nut to the torque given in specifications for Chapter 10. Install the brake drum.
7. Mount the wheels, lower the car. Tighten the wheel nuts.
8. Carry out several successive braking while driving forward and reverse to adjust the brakes and the brake pedal.
9. Check the operation of the brakes in an enclosed area.