With the vehicle jacked up and securely supported, remove the rear wheels and brake drums from both sides. (see here).
Gently lift the edge of the guard away from the body of each brake cylinder.
Inspect the inner surface of the casing and the edges (edges) cylinder. In this case, very little moisture can be detected (what is normal) in this area (usually covered in dust), but any signs of brake fluid in it indicate the need for immediate repair. A leak, no matter how small, can significantly reduce the braking force on a given wheel. It can also lead to air entering the brake system, which in turn is the cause of such a phenomenon as «soft» brake pedal.
Removing
Jack up or put the car on a two post lift (jack, wheel chocks), turn off the ignition, turn on the first gear.
Remove rear wheels.
Release the hand brake lever.
Remove brake drum. (see here).
Remove the spring guides while keeping the spacer bar in contact with the brake shield (flathead screwdriver, pliers).
Remove upper return spring (brake spring pliers).
Disconnect the automatic clearance adjuster spring from the shoe (flathead screwdriver, pliers).
Extend the brake pads.
Figure 15-1 - Removing the rear brake wheel cylinder: 1 - rear brake shield; 2 - a bolt of fastening of the wheel cylinder; 3 - rear brake wheel cylinder; 4 - brake pipe
Unscrew the brake pipe fastening fitting 4, Figure 15-1, to the rear brake wheel cylinder and install the plugs on the brake pipe and in the hole of the wheel cylinder (wrench for brake pipes, technological plugs).
Attention: It is necessary to act carefully, using the appropriate wrench to disconnect the fitting. This fitting is usually rusted or dirty, requiring a lot of effort to remove it. Don't damage the highway.
Helpful Hint: After a long period of use, the brake pipe nut «grows together» with the tube in one piece and when you try to unscrew the nut, the tube twists and breaks. In this case, just loosen the tube nut a little, then unscrew the cylinder mounting bolt and disconnect it from the tube by screwing the cylinder from its nut. After disconnecting the cylinder from the tube, the mobility of the released nut can be restored by moistening it with brake fluid and turning the nut alternately in both directions with a wrench.
Remove bolt 2 securing wheel cylinder 3 to rear brake shield 1.
...and remove the cylinder (interchangeable head 10, extension ratchet wrench).
Installation
Clean rear brake elements (metal brush).
Install the wheel cylinder on the rear brake shield and secure it with the bolt. Bolt tightening torque 14 Nm (1.4 kgf·m) (interchangeable head 10, extension, ratchet wrench, torque wrench).
Remove the plugs from the holes of the wheel cylinder and the brake pipe and screw the fitting of the brake pipe into the hole of the wheel cylinder. Connector tightening torque 14 Nm (1.4 kgf·m) (wrench for brake pipes, interchangeable insert, torque wrench).
Hook the spring of the automatic clearance adjustment mechanism to the block (flathead screwdriver, pliers).
Install top return spring (brake spring pliers).
Install the spring guides keeping the spacer bar in contact with the brake shield (flathead screwdriver, pliers).
Check outer diameter of brake pads and adjust if necessary.
Install the brake drum.
Install the rear wheel.
Bleed the brake system and, if necessary, the clutch hydraulic drive. (see here).
Check the efficiency of the service brake system.