GM 18029943
Wheel Cylinder, Rear

Begin with Wheel Cylinder replacement by raising the vehicle then taking off the tire wheel combination Brake Drum and brake shoes. Clean the Wheel Cylinder area of dirt before removing its bleeder valve but remember to plug exposed brake pipe ends when done. Discard the Wheel Cylinder brake pipe fitting then plug all open brake pipe ends before you take out the Wheel Cylinder mounting bolts and Wheel Cylinder itself. Apply threadlocker product 12345382 or its equivalent on the Wheel Cylinder shoulder where it meets the backing plate and fit the Wheel Cylinder in place. Apply handtools to run the Wheel Cylinder mounting bolts to 12 nm (106 inch lbs.). Join the brake pipe fitting to the Wheel Cylinder and torque it to 15 nm (11 ft. Lbs.) after inserting the pipe ends. Place the bleeder valve and torque it to 7 nm (62 inch lbs.), add brake shoes, set drum brakes, and put back the Brake Drum. Complete the brake system bleeding process before adjusting the parking brake and installing the tire and wheel assembly plus lowering the vehicle.

In order to change the Wheel Cylinder, first, lift and support the car, unfasten the tire and wheel, then the Brake Drum and shoes. Clean any dirt around and be sure to take off bleeder valve and seal the exposed brake pipe fitting ends by capping them in order to avoid fluid excess and dirt. Release the brake pipe fitting from the Wheel Cylinder and plug the available ends of the brake pipe. Then remove the mount bolts of the Wheel Cylinder and pull it out. For installation, loctite gm p/n 12345382 or equal to the Wheel Cylinder shoulder face that contacts backing plate, position Wheel Cylinder to the backing plate and install Wheel Cylinder mounting bolts tightening to 12 nm (106 in. Lbs.). Take out the plugs from the ends of the brakes pipe; attach the brakes pipe fitting to Wheel Cylinder and tighten it on 15 nm (11 ft. Lbs.). Install the bleeder valve a tightening to 7 nm (62 inch-lbs.). Move to install the brake shoes, align the drum brakes and fix the Brake Drum. Bleed the brake hydraulic system, change the parking brake, install the brake tire and wheel assembly, and lastly, lower the vehicle.

To replace the Wheel Cylinder you should first lift and support the vehicle before taking the tires and wheels off. Steer clear of the spring mechanism on the rear brake shoes to prevent finger injuries. Keep both hands away from the splash shield and backing plate when you work to stop brake component bending and when you handle the adjuster spring to prevent damage. You must remove all dirt and foreign matter from the Wheel Cylinder inlet area, around the pilot parts, and over the bleeder valve. After you take off the brake shoes and bleeder valve, use the brake pipe inlet tube nut to detach the Brake Line while using plugging tools to block the exit. Uninstall the Wheel Cylinder bolts along with the component and prepare the Wheel Cylinder face for reuse. To assemble the Wheel Cylinder securely, use loctite gm p/n 12345382 or a substitute product by coating the shoulder area of the Wheel Cylinder on the backing plate. Set the Wheel Cylinder into place and keep it fixed. Fasten Wheel Cylinder mounting bolts by turning them to 12 nm (110 inch lbs.) torque values. Install the brake pipe inlet tube tighten the nut to 17 nm (12 ft. Lbs.) after you put in the bleeder valve and torque it to 7 nm via 62 inch lbs. First remove the wheels to bleed the Wheel Cylinder then put on the brake shoes and wheels again before lowering the vehicle.

Start the Wheel Cylinder service process by taking it off from its current position. Unbolt the Wheel Cylinder then peel back the boots before taking out the pistons seals and spring. Take out the bleeder valve from your system after finishing these steps. Check the cylinder bore interior alongside the Piston parts for damage and irregularities. Wipe corrosion marks with a crocus cloth then get a new Wheel Cylinder when the cylinder bore fails to restore. Put washed parts in denatured alcohol then air dry them using non-lubricated compressed air. Petroleum brake fluid helps these new seals function better. Put the bleeder valve in position then tighten it to 7 nm (62 inch lbs.). Add the spring afterward along with the new seal, pistons, and boots. Finally, install the Wheel Cylinder.

Vehicle support and wheel removal starts by gaining vehicle height then dismounting tires and wheels. Avoid hands near rear Brake Shoe springs because they might get pinched. Bending of the splash shield or backing plate may produce brake chatter or pulsation so users should avoid touching these components. Adjuster spring damage will occur from excessive stretch. The Wheel Cylinder inlet, pilot, and bleeder valve need to be cleared of all foreign matter and dirt buildup. Start by removing brake shoes and linings followed by uninstalling the bleeder valve then the brake pipe inlet tube nut and Brake Line while sealing the opening to stop fluid loss and protect against contamination. Start by taking out Wheel Cylinder mounting bolts with the Wheel Cylinder then cleaning the backing plate along with the Wheel Cylinder when sealant reuse is planned. Installation requires loctite gm p/n 12345382 or equivalent application on the Wheel Cylinder shoulder face before setting it in position. Tighten all Wheel Cylinder mounting bolts to 12 nm (110 inch lbs.) torque specifications. Screw and tighten the brake pipe inlet tube nut to 17 nm (12 ft. Lbs.). Next, secure the bleeder valve with 7 nm (62 inch lbs.). After bleeding the Wheel Cylinder professionals should install brake shoes and linings followed by wheel installation and descending the vehicle.

Take off the boots and then remove the pistons, seals, and spring.