GM Cavalier/Sunbird/Skyhawk/Firenza 1982-1994

Wheel Cylinders

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REMOVAL & INSTALLATION



See Figures 1, 2, 3, 4 and 5

  1. Raise and safely support the vehicle.
  2.  
  3. Remove the tire and wheel assembly.
  4.  
  5. Following the procedures located in this section, remove the brake drum and brake shoes (if necessary for access).
  6.  



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Fig. Fig. 1: Remove the brake drum, then remove the brake shoes if necessary for access to the wheel cylinder

  1. Unfasten the inlet brake fluid line, then cap the line to prevent contamination from entering.
  2.  



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Fig. Fig. 2: Disconnect and plug the brake line from the rear of the backing plate

  1. If necessary for access to the cylinder, remove the hub and bearing assembly. On some vehicles, you must loosen the hub assembly bolts and slide the hub forward for additional clearance to remove the wheel cylinder.
  2.  
  3. Clean any dirt from around the wheel cylinder.
  4.  

On some vehicles, you will need a #6 Torx® driver to remove the wheel cylinder bolts.

  1. To remove the round retainer type cylinders, insert two awls or pins into the access slots between the wheel cylinder pilot and the retainer locking tabs. Bend both tabs away simultaneously. The wheel cylinder can be removed, as the retainer is released.
  2.  



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Fig. Fig. 3: Two awls may be used to bend the retainer stubs, releasing the wheel cylinder

  1. To remove the bolted wheel cylinders, unfasten the wheel cylinder bolts, then remove the cylinder from the backing plate.
  2.  



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Fig. Fig. 4: Exploded view of the wheel cylinder components



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Fig. Fig. 5: If equipped with a round retainer type wheel cylinder, use a socket extension to seat the retainer

To install:
  1. Apply a very thin coating of silicone sealer to the cylinder mounting surface.
  2.  
  3. For round retainer type wheel cylinders, position the cylinder and hold it in place with a wooden block between the cylinder and the axle flange. Carefully seat the new retainer clip, using a 1 1 / 8 in. 12-point socket and socket extension (to help preserve your fingers). The socket is used to assure that the retainer seats evenly.
  4.  
  5. For bolt type wheel cylinders, position, install the cylinder to the backing plate and fasten the attaching bolts. Tighten to 15 ft. lbs. (20 Nm).
  6.  
  7. Uncap, then connect the brake line to the wheel cylinder. Tighten the inlet tube nut to 17 ft. lbs. (23 Nm).
  8.  
  9. If removed, install the hub and bearing assembly. Tighten to 43 ft. lbs. (58 Nm).
  10.  
  11. Install the brake shoes, if removed, and the brake drum.
  12.  
  13. Install the tire and wheel assembly.
  14.  
  15. Carefully lower the vehicle, then tighten the lug nuts to 103 ft. lbs. (140 Nm).
  16.  
  17. Properly bleed the hydraulic brake system.
  18.  

OVERHAUL



See Figures 6 through 15

Wheel cylinder overhaul kits may be available, but often at little or no savings over a reconditioned wheel cylinder. It often makes sense with these components to substitute a new or reconditioned part instead of attempting an overhaul.

If no replacement is available, or you would prefer to overhaul your wheel cylinders, the following procedure may be used. When rebuilding and installing wheel cylinders, avoid getting any contaminants into the system. Always use clean, new, high quality brake fluid. If dirty or improper fluid has been used, it will be necessary to drain the entire system, flush the system with proper brake fluid, replace all rubber components, then refill and bleed the system.

  1. Remove the wheel cylinder from the vehicle and place on a clean workbench.
  2.  
  3. First remove and discard the old rubber boots, then withdraw the pistons. Piston cylinders are equipped with seals and a spring assembly, all located behind the pistons in the cylinder bore.
  4.  



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Fig. Fig. 6: Remove the outer boots from the wheel cylinder

  1. Remove the remaining inner components, seals and spring assembly. Compressed air may be useful in removing these components. If no compressed air is available, be VERY careful not to score the wheel cylinder bore when removing parts from it. Discard all components for which replacements were supplied in the rebuild kit.
  2.  



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Fig. Fig. 7: Compressed air can be used to remove the pistons and seals



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Fig. Fig. 8: Remove the pistons, cup seals and spring from the cylinder

  1. Wash the cylinder and metal parts in denatured alcohol or clean brake fluid.
  2.  



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Fig. Fig. 9: Use brake fluid and a soft brush to clean the pistons ...



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Fig. Fig. 10: ... and the bore of the wheel cylinder


WARNING
Never use a mineral-based solvent such as gasoline, kerosene or paint thinner for cleaning purposes. These solvents will swell rubber components and quickly deteriorate them.

  1. Allow the parts to air dry or use compressed air. Do not use rags for cleaning, since lint will remain in the cylinder bore.
  2.  
  3. Inspect the piston and replace it if it shows scratches.
  4.  



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Fig. Fig. 11: Once cleaned and inspected, the wheel cylinder is ready for assembly

  1. Lubricate the cylinder bore and seals using clean brake fluid.
  2.  
  3. Position the spring assembly.
  4.  
  5. Install the inner seals, then the pistons.
  6.  



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Fig. Fig. 12: Lubricate the cup seals with brake fluid



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Fig. Fig. 13: Install the spring, then the cup seals in the bore



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Fig. Fig. 14: Lightly lubricate the pistons, then install them

  1. Insert the new boots into the counterbores by hand. Do not lubricate the boots.
  2.  



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Fig. Fig. 15: The boots can now be installed over the wheel cylinder ends

  1. Install the wheel cylinder.
  2.  

 
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