Q: How to overhaul a wheel cylinder on Mercury Cougar?
A: If an overhaul is indicated, usually because of fluid leakage or sticky operation, explore all options before beginning the job. New wheel cylinders are available, which makes this job quite easy. If its decided to rebuild the wheel cylinder, make sure that a rebuild kit is available before proceeding. Never overhaul only one wheel cylinder-always rebuild both of them at the same time. To remove, raise the rear of the vehicle and support it securely on jack stands. Block the front wheels to keep the vehicle from rolling. Remove the brake shoe assembly. Remove all dirt and foreign material from around the wheel cylinder. Disconnect the Brake Line. Don't pull the brake line away from the wheel cylinder. Remove the wheel cylinder mounting bolts. 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. To overhaul, remove the bleeder screw,cups, pistons, boots and spring assembly from the wheel cylinder body. Clean the wheel cylinder with brake fluid, denatured alcohol or brake system cleaner. Use compressed air to remove excess fluid from the wheel cylinder and to blow out the passages. Check the cylinder bore for corrosion and score marks. Crocus cloth can be used to remove light corrosion and stains, but the cylinder must be replaced with a new one if the defects cannot be removed easily, or if the bore is scored. Lubricate the new cups with brake fluid. Assemble the brake cylinder components. Make sure the cup lips face in. To install, place the wheel cylinder in position and install the bolts. Connect the brake line and install the brake shoe assembly. Bleed the brakes.