The maximum diameter of the working surface of the brake drum (maximum wear) - 229.5 mm. If this size is larger, the drum must be replaced.
The marking is on the inside of the brake drum. The maximum diameter is indicated.
Part numbers for brake drums and other items see here.
Removing
Set the stops under the front wheels, turn on 1st gear. Jack up the car on the desired side.
If work is being done on a lift, place the vehicle on a two-post lift and turn off the ignition.
Remove rear wheel.
Release the hand brake lever.
Raise the vehicle to a height convenient for work.
Pry off the cap of the brake drum mounting nut (mounting blade, hammer).
and take it off.
Figure 13-1 - Removing the rear brake drum: 1 - a nut of fastening of a brake drum; 2 - brake drum; 3 - axis of the rear wheel hub
Unscrew the nut 1, Figure 13-1, fastening the brake drum to the axis 3 of the rear wheel hub (interchangeable head for 36, extension and collar).
Remove brake drum.
The brake drum is made in one piece with the hub, on the shoulder of which the master ring of the wheel speed sensor is pressed. Do not press the bearing out of the brake drum unless absolutely necessary. A dismantled bearing cannot be reused.
Checking the technical condition
Check the wheel bearing for ease of rotation and play. Replace bearing if necessary.
Attention. Brake drums must be the same diameter. When boring one of the drums, be sure to bore the second drum.
Attention. When replacing a brake drum on one side, be sure to replace the brake drum on the opposite side.
Attention. When replacing brake drums, be sure to replace the brake pads.
Parameters of brake drums
Parameter Nominal inner diameter of the brake drum, mm 228.5 Maximum permissible inner diameter of the brake drum, mm 229.5
Measure the inner diameter of the brake drum in two mutually perpendicular directions. Compare the measurement results with the data given in Table 13-1. Replace brake drum if necessary (calipers).
If there are deep scratches, waviness on the working surface of the brake drum, bore the drum. Take measurements again. Compare the measurement results with the data given in Table 13-1. If necessary, replace the brake drum.
Installation
Clean rear brake elements (metal brush).
When installing the old drum, use a file to remove the shoulder on the working surface of the drum, formed as a result of wear.
When replacing the brake drum, check the outside diameter of the brake pads and adjust if necessary.
Before installing the drum, the brake shoes must be brought to their normal, original position. That is, if the brake pads are spread wider than necessary, the brake drum simply will not «sit down» on them. How to reset the clearance adjuster (see here).
Install the brake drum on the rear wheel hub axle and secure it with a nut. Tightening torque for hub nut 280 Nm (28 kgf·m) (interchangeable head 36, extension and knob, torque wrench).
Note. According to the technical regulations, the hub nut must be used new (nut dimensions: M24x1.5 wrench 36), but you can also use the restored old one by crushing its shoulder in three places with a hammer, as shown in the photo.
Attention. It is forbidden to move the car with the hub nut loose, as this will damage the bearing cage.
Adjust the gap between the brake shoes and the drum by pressing the brake pedal 10-15 times. Each time you press it, you should hear the knob click. As soon as the clicks stop, the gap is set.
Check the operation and, if necessary, adjust the parking brake actuator.
Press the protective cap into the hub.
Install the rear wheel.
Check for ease of rotation of the wheel. It is allowed to lightly touch the drum on the pads.
Check and, if necessary, top up the brake fluid level in the brake fluid reservoir.
Check the efficiency of the service brake system.