Scion 47550-20211 Cylinder Assembly, Rear Wheel Brake

To remove the wheel cylinder, begin by raising the rear of the vehicle and securely supporting it on jack stands. Block the front wheels to prevent rolling. Proceed to remove the Brake Shoe Set. Ensure all dirt and foreign material are cleared from around the wheel cylinder. If available, disconnect the brake line using a flare-nut wrench, taking care not to pull the brake line away from the wheel cylinder. Remove the wheel cylinder mounting bolt. Detach the wheel cylinder from the brake backing plate and place it on a clean workbench. Immediately plug the brake line to prevent fluid loss and contamination. For installation, position the wheel cylinder and loosely install the bolt. Connect the brake line to the cylinder, being cautious not to cross-thread the O-ring. Tighten the wheel cylinder bolt to the specified torque. Securely tighten the brake line fitting and proceed to install the brake shoes and drum. Bleed the brakes to remove any air. Install the wheel and lug nuts. Lower the vehicle to the ground and tighten the lug nuts to the proper torque. Before driving the vehicle, carefully check the operation of the brakes.

If due to fluid leakage of wheel cylinder the brake shoes get contaminated then they must be renewed on this side as well as on the other side also regardless of the fact that only one side is burnt. To initiate the process of removal, remove the brake drum and rub the wheel cylinder seals against the wheel; if accompanied with brake dust, then it implies a leakage, while dampness implies a faulty cylinder. Albeit that wheel cylinder repair kits are not as easily obtainable, it may be wise to ask in respect to them. Also, in the event that one cylinder was ailing, the next one could also be affected, and if so, the leak could have developed to affect the brake shoes in the process and therefore, both necessitating new shoes. To reduce the loss of the brake fluid, it is recommended that you unscrew the master cylinder reservoir cap and put the cap and the cover in a polythene or clamp the flexible hose near the wheel cylinder. Fully extend the brake shoes at the top part to free the bottom part of the wheel cylinder, and by so doing be able to hold it by the automatic adjuster in preparation for the withdrawal. Wash the surrounding area of the hydraulic union situated at the rear of the wheel cylinder, you are then required to undo the union nut, which can be very much tightened; you can therefore smear some penetrating oil before undoing the nut. Remove the bolt that fastens the wheel cylinder to the back plate to detach the latter, and cap off the hydraulic unions to minimize issue of dirt and fluid leakage. At the present time, holing service procedures or parts are not offered, which means it is best to replace the wheel cylinder as an assembly. For refitting clean the backplate remove the plug from the hydralulic pipe and place the cylinder onto the backplate while turning the hydraulic union nut by hand. After applying the pressure, apply the nut of the hydraulic union and tighten up the mounting bolt completely. Pull out the automatic brake adjuster in order to bring the brake shoes in contact with the wheel cylinder pistons and if any clamp or any seal was applied to reduce the amount of expelled fluid, then it should be removed. Repair or replace the brake drum and flush the hydraulic system and if measures were taken to avoid loss of the fluid only the rear brake requires bleeding. Finally, check the brake before taking the car back to its normal use.