GM Corsica/Beretta 1988-1996 Repair Guide

Wheel Cylinders

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REMOVAL & INSTALLATION



Except 1988-91 Beretta

See Figures 1 and 2

  1. Raise and safely support the rear of the vehicle with jackstands.
  2.  
  3. Remove the tire and wheel assembly, then remove the brake drum.
  4.  
  5. Clean any dirt from around the wheel cylinder.
  6.  
  7. Disconnect and plug the brake line from the wheel cylinder.
  8.  
  9. Remove the wheel cylinder bolts using a #6 Torx® socket.
  10.  
  11. Remove the wheel cylinder from the brake backing plate.
  12.  



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Fig. Fig. 1: Unfasten, then plug the brake line from the wheel cylinder



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Fig. Fig. 2: Unfasten the wheel cylinder-to-brake backing plate bolts ...

To install:
  1. Position the wheel cylinder assembly and hold in place with a wooden block between the cylinder and axle flange.
  2.  
  3. Install the wheel cylinder bolts using a # 6 Torx socket. Tighten the bolts to 15 ft. lbs. (20 Nm).
  4.  
  5. Uncap and attach the fluid line, then tighten the tube nut to 13 ft. lbs. (17 Nm).
  6.  
  7. Install the brake drum and the wheel and tire assembly.
  8.  
  9. Carefully lower the vehicle.
  10.  
  11. Bleed the brake system. Inspect the brake operation.
  12.  

1988-91 Beretta

See Figures 3, 4, 5, 6, 7 and 8

  1. Raise and support the rear of the vehicle on jackstands.
  2.  
  3. Remove the tire and wheel assembly, then remove the brake drum.
  4.  
  5. Remove the brake shoes and attaching hardware.
  6.  
  7. Clean any dirt from around the wheel cylinder.
  8.  
  9. Disconnect and plug the brake line from the wheel cylinder.
  10.  
  11. Remove the wheel cylinder-to-backing plate bolt and lockwasher.
  12.  
  13. Remove the wheel cylinder from the brake backing plate.
  14.  

To install:
  1. To install, apply a liquid gasket to the shoulder of the wheel cylinder that faces the backing plate and reverse the removal procedures. Tighten the wheel cylinder-to-backing plate bolt to 106 inch lbs. (12 Nm) and the brake line-to-wheel cylinder to 13 ft. lbs. (17 Nm).
  2.  
  3. Unplug and connect the brake line to the wheel cylinder
  4.  
  5. Install the brake shoes, as outlined earlier in this section.
  6.  
  7. Install the brake drum and wheel and tire assembly.
  8.  
  9. Carefully lower the vehicle.
  10.  
  11. Bleed the brake system. Inspect the brake operation.
  12.  

OVERHAUL



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.  
  5. 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.
  6.  
  7. Wash the cylinder and metal parts in denatured alcohol or clean brake fluid.
  8.  



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Fig. Fig. 3: Remove the outer boots from the wheel cylinder



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Fig. Fig. 4: Compressed air can be used to remove the pistons and seals



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Fig. Fig. 5: Remove the pistons, cup seals and spring from the cylinder



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Fig. Fig. 6: Use brake fluid and a soft brush to clean the pistons ...



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Fig. Fig. 7: ... 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. 8: Once cleaned and inspected, the wheel cylinder is ready for assembly

See Figures 9, 10, 11 and 12

  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.  
  7. Insert the new boots into the counterbores by hand. Do not lubricate the boots.
  8.  
  9. Install the wheel cylinder.
  10.  



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Fig. Fig. 9: Lubricate the cup seals with brake fluid



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Fig. Fig. 10: Install the spring, then the cup seals in the bore



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Fig. Fig. 11: Lightly lubricate the pistons, then install them



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Fig. Fig. 12: The boots can now be installed over the wheel cylinder ends

 
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