Wheel Cylinder


Care must be taken when installing new or reconditioned wheel cylinders on cars equipped with wheel cylinder piston stops. The rubber dust boots and the pistons must be squeezed into the cylinder before it is tightened to the backing plate. If this is not done, the pistons jam against the stops causing hydraulic fluid leaks and erratic brake performance.

Hydraulic system parts should not be allowed to come in contact with oil or grease. They should not be handled with greasy hands. Even a trace of any petroleum-based product is sufficient to cause damage to the rubber parts.
  • Wheel cylinder kits can be purchased when replacing wheel cylinders. The kits generally contain the dust boots, cups and springs. Some kits also include the piston.
  • Since brake hoses are an important link in the hydraulic system, it is recommended they be replaced when a new cylinder is to be installed or when the old cylinder is to be reconditioned. Remove the brake shoe assemblies from the backing plate before proceeding. The smallest amount of brake fluid contaminates the friction surface of the brake lining.
  • Using two appropriate wrenches, disconnect the hydraulic hose from the steel line located on the chassis. On solid rear axles, use the appropriate tubing wrench and disconnect the hydraulic line where it enters the wheel cylinder. Care must be exercised in removing this steel line. It might be bent at this point and be difficult to install once new wheel cylinders are mounted to the backing plate.
  • Remove the plates, shims, and bolts that hold the wheel cylinder to the backing plate. Some later designed wheel cylinders are held to the backing plate with a retaining ring that can be removed with two small picks.
  • Remove the wheel cylinder from the backing plate and clean the area with a proper cleaning solvent.