ParkAvenue 1997-1999

Wheel Cylinders

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Overhaul



Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

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.



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Fig. Exploded view of the wheel cylinder components - 1987-90 vehicles

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



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



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



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



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

  1. Install the wheel cylinder.
  2.  

Removal & Installation



Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

  1. Raise and safely support the vehicle. Remove the rear wheel and tire assembly.
  2.  
  3. Clean the area around the wheel cylinder assembly inlet and pilot.
  4.  
  5. Remove the brake drum assembly.
  6.  
  7. Remove any brake components, necessary for access to the wheel cylinder.
  8.  
  9. Disconnect and plug the inlet brake line.
  10.  



Click image to see an enlarged view

Fig. Always use a flare nut wrench when disconnecting brake lines



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Fig. Pull the brake line from the rear of the backing plate

  1. Remove the wheel cylinder-to-backing plate mounting screws and/or lockwashers, then remove the wheel cylinder assembly.
  2.  



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Fig. The wheel cylinder is usually secured to the backing plate with 2 mounting bolts



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Fig. Use a box end wrench to remove the 2 wheel cylinder mounting bolts ...



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Fig. ... then remove the wheel cylinder from the brake backing plate

To install:

  1. Apply Loctite® Master Gasket, or equivalent to the wheel cylinder shoulder face that contact the backing plate.
  2.  
  3. Position the wheel cylinder assembly to the backing plate, then install the retaining screws/bolts and/or lockwashers. Tighten the retainers to 106 inch lbs. (12 Nm).
  4.  
  5. Unplug and connect the inlet brake line. Tighten the line nut to 12 ft. lbs. (17 Nm), using a flare nut wrench.
  6.  
  7. Install any brake components that were removed for access to the wheel cylinder.
  8.  
  9. Install the brake drum and the wheel and tire assembly.
  10.  
  11. Carefully lower the vehicle, then properly bleed the brake system, as outlined in this section.
  12.  

 
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