GM 91175624
Wheel Cylinder

First support the vehicle in its raised position before taking away the wheel rear tire assembly. Remove the Brake Drum and brake shoes thereafter. Wash Wheel Cylinder and Brake Backing Plate outer surface with gm non-chlorinated brake parts cleaner (Part 12377981) or a suitable substitute. Apply gm non-chlorinated brake parts cleaner to both the brake pipe and the inboard space of the Brake Backing Plate. Loosen the 2 brake pipe flare nuts on the right Wheel Cylinder but keep brake fluid from leaking out and unscrew just the brake pipe nut on the left Wheel Cylinder while stopping fluid release. Untighten the left rear brake bleeder valve bolts and valve cap to remove them. To access the right Wheel Cylinder replace the bleeder valve cap from a front brake bleeder valve then unscrew the 2 brake pipes and install them back with the bleeder valve caps. Detach the brake pipe from the left Wheel Cylinder then insert the bleeder valve cap for sealing. Take out the Wheel Cylinder from its back plate and detach the gasket from the Wheel Cylinder part. Install the new gasket if necessary and put it between the Wheel Cylinder and backing plate before attaching the Wheel Cylinder to its place. Anchor the Wheel Cylinder with its nuts before tightening them to 8.5 nm (78 inch lbs.). Fit the brake pipes ending to the Wheel Cylinder through their caps for both right and left sides. Secure the 2 flare nuts on the right Wheel Cylinder at 10 nm (12 ft. Lbs.) torque. On the left Wheel Cylinder tighten the flare nut to 16 nm (12 ft. Lbs.) after installing the brake pipe cap. When servicing the right Wheel Cylinder put its cap into the front brake release valve before adding it to the left rear valve. Install new brake shoes and drum then attach the rear tire and wheel parts. Put the car back down to ground level before pumping the brake brake component parts.

Remove the 2 caps from the 2 brake pipes and install them to the wheel cylinder, tightening the 2 flare nuts to 16 Nm (12 ft. lbs.).