Drum Brake rear wheels

Brake Cylinder rear brake

The construction of the drum brake of the rear wheels is shown in Fig. 8.12.

Removal, check and installation of components of brake pads

On the reverse side of the brake control board located inspection opening, which plugged (Fig. 8.13).

In order to verify the thickness of the brake pads, remove the plug control inspection hole, light his flashlight and visually estimate the thickness of the brake lining. If the lining is worn and its thickness is about 2 mm or less, you need to replace the brake pads in the kit on both wheels.

Removing the brake pads

Removing the brake pads drum brake rear wheels performed as follows:

- To establish an emphasis under the front wheels, release the bolts of the rear wheel, lift the rear of the car a jack and place it on a support;

- Remove the appropriate rear wheel;

- Taking advantage of using a flathead screwdriver as a lever, and helping himself with a hammer, remove the hub cap of a nut in the center of the brake drum (Fig. 8.14);

- Remove the cotter pin from the hub nut and remove the lock cover. Discard the pin to waste, since the installation must use the new one;

- Loosen the nut of a nave, remove the thrust washer and remove the outer bearing from the center of the drum;

- Fully release the parking brake cable to get the best possible slack rope;

- Insert a screwdriver into one of the holes in the drum is designed for wheel bolts and screwdriver acting as a lever to lift the installation wedge 10 (see. Fig. 8.12) and slide it up to bring together the maximum brake pads;

- Remove the brake drum with the axis of the wheel manually. If it is not removed, the light hammer with a soft head on the edges of the drum try move him or use a universal stripper, securing it on the drum using a wheel bolt. You can also soak the outside shoulder of the cap nut and hub using a wooden block with short blows to end his shift drum, moving the bar on the opposite side of the drum;

- Measure the thickness of each brake shoe lining at several points;

- Note the location of the brake pads and springs and check rib pads to facilitate their installation;

- Push the back of the finger on the pin 14 (see. Fig. 8.12), grab a pair of pliers plate spring 7 6 from the outside pads, push it and then turn to the position as head of the pin can not be threaded through the spring plate. Remove the spring plate, a spring and a pin. Do this on both stocks;

- Take the hand pad their bottom part and raised by a separate block from the lower supports and remove them from the poles. Disconnect vacated the lower return spring 3;

- Separate the upper ends of the two pads from the wheel brake cylinder 11, taking care not to damage the seal of the wheel cylinder, and disconnect the parking brake cable from the trailing brake shoe (Fig. 8.15);

- Moving cautiously, remove the pad assembly with a brake board;

- Before disassembly remember how pads arranged all the details;

- Hold brake pads in a vise and use pliers unhook the top returnable spring 4 (see. Fig. 8.12) and remove the spring wedge 2. Disconnect the two pads and Expanding the bar located at the top (Fig. 8.16, a);

- Remove the expander bar pads and spring (Fig. 8.16, b). Remove as a wedge, but pay attention to how it is installed.

Checking the technical condition of removed parts

Check the technical condition of the parts removed drum rear brakes performed as follows:

- Thoroughly clean all parts;

- Carefully remove dust from the drum, but avoid inhaling it, as it is dangerous to health;

- Clean the outside of the drum and check for obvious signs of wear or damage such as cracks around the holes for the wheel bolts;

- Carefully inspect the inside of the drum. If you notice a significant scoring the drum must be replaced. Usually, at the edge of the inside of the drum is formed ridge, consisting of a mixture of pulverized material friction linings and rust. It must be removed, leaving a smooth surface that can be polished fine-grained sandpaper. However, if the crest was formed due to wear of the friction surface, the drum should be replaced by a new one;

- If necessary, measure the inner diameter of the drum at several points using a micrometer callipers for determining the degree of wear and roundness of the drum. To evaluate ovality, do paired measurement points disposed at right angles to each other, and compare the results. The drum may be abraded under the condition that after this diameter is greater than the maximum permissible. If any need to grind the drum, it is necessary to process both the drum to ensure the equality of the two internal diameters of the drums. If you can not handle the drum, both drums must be replaced by new ones;

- Inspect all parts, check for wear or damage and replace if necessary. All return springs must be replaced with new ones, regardless of their appearance;

- Remove the rubber dust caps and check the brake cylinder brake cylinder for leaks. Both the cylinder piston must move freely;

- Lightly grease the brake the contact expander strap and handbrake lever.

Installing the brake pads

Install the brake pads drum brake rear wheels performed as follows:

- Trailer spring 8 (see. Fig. 8.12) to the trailing brake shoe. The second end of the spring to hook the expander strap 9 and insert the bar into place on the trailing brake shoe (Fig. 8.17);

- Establish a wedge between the trailing brake shoe and expander strap. The bulge on the wedge (arrow, Fig. 8.18) should face away from the pad;

- Set the lever 5 (see. Fig. 8.12) parking brake upwind brake shoe expander in the bar;

- With the help of pliers, hook the top of the return spring to the incoming brake pads and spacer bar (arrow, Fig. 8.19);

- With the help of pliers, hook the spring 2 (see. Fig. 8.12) to the wedge 10 and a trailing brake shoe (Fig. 8.20);

- Prior to installation, clean the brake shield and apply a thin layer of high-melting grease designed for the brake system on the surface of a brake board, which contact pads. Do not allow grease to the friction linings;

- Place the pads on the brake assembly shield;

- Connect the cable to the parking brake lever and insert the upper part of the shoes into the grooves of the pistons of the wheel cylinder;

- Attach the lower return spring 3 (see. Fig. 8.12) to the pads, and then insert the lower ends of the lower support pad;

- Tap the pads to center them on a brake board, and then insert the pin 14 blocks, put a plate spring 6 and 7 of the springs;

- Completely reduced brake pads, for raising this wedge;

- Lightly grease the sleeve of the drum and carefully place in the axle of the wheel assembly to the drum bearing race, the bearing and the inner sleeve;

- Establish the external bearing and thrust washer, making sure the correct location of wave washer in the groove axis;

- Install the hub nut and tighten it so much that she barely touched the puck, while rotating the drum to set the bearings of the drum in place. Gradually release the hub nut to a position where you can be a little screwdriver to move the puck from side to side by applying a small force;

- The hub nut secure a new cotter pin;

- Set cap nut hub;

- Repeat the procedure on the second rear brake;

- Several times sharply press the brake pedal to resume normal pedal force (without the amplifier), to activate the mechanism for adjusting the gaps and adjust the clearance between the lining and drum;

- Check and, if necessary, adjust the parking brake;

- Set the wheels, lower the car on the earth and tighten wheel bolts to torque;

- Check brake fluid level, top up if necessary.