ParkAvenue 1997-1999

Brake Shoes

Print

Adjustment



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

The drum brakes self-adjust anytime the brakes are applied, with no vehicle motion required. This system works well and no manual adjustment is usually necessary. Adjustment will be required when new brake shoes are installed. The following procedure is with the brake drum removed.

  1. Raise and support the car safely.
  2.  
  3. Mark the relation of wheel to studs, so you install it in the same location.
  4.  
  5. Remove the wheel and tire assembly.
  6.  
  7. Remove the brake drum.
  8.  
  9. Make certain the parking brake is off and the brake shoes are sitting against the stops. If not readjust the parking brake, as outlined later in this section.
  10.  
  11. Measure the drum inside diameter using a suitable drum-to-brake shoe clearance gauge.
  12.  



Click image to see an enlarged view

Fig. Use a suitable gauge to measure the drum and shoes for adjustment

  1. Turning the adjuster nut (star wheel on the adjuster), adjust the shoe and lining diameter to be 0.050 in. (1.27mm) less than the inside drum diameter for each rear wheel. Go slowly and don't overtighten or force the drum on. It's very difficult to remove the drum on an overadjusted system.
  2.  



Click image to see an enlarged view

Fig. Location of the drum brake adjuster screw assembly

  1. If you've over-adjusted or the drum is hard to remove; remove the access hole plug from the backing plate. Insert a flat tool though the hole and press in to push the park brake lever off its stop. This allows the lining to retract. You must not remove the drum and reassemble the brakes. Don't pry on the backing plate. If necessary, insert a punch through the hole at the bottom of the splash shield and tap gently to loosen drum.
  2.  
  3. After adjustment, install the drum and the tire and wheel assembly.
  4.  
  5. Perform the adjustment procedure at the other rear wheel and tire assembly.
  6.  
  7. Carefully lower the vehicle, then tighten the lug nuts to 100 ft. lbs. (136 Nm).
  8.  
  9. Apply and release the brakes about 30-12 times with normal pedal force, pausing about one second between pedal applications.
  10.  

Inspection



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

After removing the brake drum, inspect the brake shoes. If the lining is worn down to within 1 / 32 in. (0.8mm) above the rivet, the shoes must be replaced.

This figure may disagree with your state's automobile inspection laws. If the brake lining is soaked with brake fluid or grease, it must be replaced. If this is the case, the brake drum should be sanded with crocus cloth to remove all traces of brake fluid, and the wheel cylinders should be rebuilt. Clean all grit from the friction surface of the drum before replacing it.

If the lining is chipped, cracked or otherwise damaged, it must be replaced with a new lining.

Always replace the brake linings in sets of two on both ends of the axle. Never replace just one shoe or both shoes on one side.

Check the condition of the shoes, retracting springs and hold-down springs for signs of overheating. If the shoes or springs have a slight blue color, this indicates overheating, then replacement of the shoes and springs is recommended. The wheel cylinders should be rebuilt as a precaution against future problems.

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


CAUTION
Older brake pads or shoes may contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning the brake surfaces, use a commercially available brake cleaning fluid.



Click image to see an enlarged view

Fig. Installed view of drum brake components



Click image to see an enlarged view

Fig. Exploded view of drum brake components

Specific to:

Buick LeSabre 1986-1990

Buick Park Avenue 1996-1999

Oldsmobile Delta 88 1986-1988

Pontiac Bonneville 1987-1990

  1. Raise and safely support the vehicle. Mark the relation ship of wheel to studs in the bearing flange, for reference during assembly. Remove the tire and wheel.
  2.  
  3. Mark the relationship of drum to the bearing flange, for reference during assembly. Remove the brake drum assembly. Clean the brake surfaces, using a commercially available brake cleaning fluid.
  4.  
  5. For additional clearance, you can remove the hub and bearing, prior to brake component removal, as follows:
    1. Unfasten the hub and bearing Torx ® retaining bolts, then carefully remove the hub and bearing.
    2.  
    3. Reinstall the hub retaining bolts to hold the brake backing plates and brake components in place.
    4.  



    Click image to see an enlarged view

    Fig. Unfasten the Torx® bolts securing the hub and bearing to the backing plate ...



    Click image to see an enlarged view

    Fig. ...and remove the hub and bearing, but make sure to reinstall the bolts in the backing plate

  6.  
  7. Remove the actuator and the upper return spring with the proper tools.
  8.  



Click image to see an enlarged view

Fig. Use a pair of pliers to unhook the actuator spring



Click image to see an enlarged view

Fig. There are special pliers available to unhook the upper return spring

  1. Disconnect the spring connecting link, adjuster actuator and, if replacing the shoe and linings, the hold-down washer.
  2.  



Click image to see an enlarged view

Fig. Remove the spring connecting link and adjuster actuator

  1. Remove the hold-down springs and the pins, using pliers or a special tool for that purpose.
  2.  



Click image to see an enlarged view

Fig. Although there are special tools available, you can also use pliers to remove the hold-down springs and pins

  1. Remove the adjuster screw assembly.
  2.  



Click image to see an enlarged view

Fig. Remove the adjuster screw assembly

  1. Unhook the left (adjuster) shoe and lining from the lower return spring.
  2.  



Click image to see an enlarged view

Fig. Remove the left (adjuster) shoe and lining, unhooking it from the lower return spring

  1. Unhook the parking brake cable from the lever and the right shoe and lining, then remove the right shoe and lining from the vehicle.
  2.  



Click image to see an enlarged view

Fig. Unhook the parking brake cable from the right brake shoe and parking brake lever assembly

  1. If necessary, remove the retaining ring, pin and spring washer securing the parking brake lever to the shoe and lining.
  2.  
  3. Clean off the brake backing plate, then lubricate the backing plate as shown in the accompanying figure.
  4.  



Click image to see an enlarged view

Fig. Clean the areas on the backing plate which are to be lubricated ...



Click image to see an enlarged view

Fig. ...then lubricate the areas with a suitable grease as shown

  1. Inspect all of the brake components. If any of them are of doubtful strength or quality, due to discoloration from heat, overstress or wear, the parts should be replaced.
  2.  



Click image to see an enlarged view

Fig. Exploded view of the drum brake components - 1987-90 vehicles

To install:

  1. Install the parking brake lever on the shoe and lining and retain with the spring washer, pin and retaining ring. Install the spring washer with the concave side against the parking brake lever.
  2.  
  3. Install the adjuster pin in the shoe and lining so that the pin projects 0.275-0.283 in. (7.0-7.2mm) from the side of the shoe web where the adjuster actuator is installed.
  4.  
  5. Disassemble, clean and reassemble the adjusting screw, as follows:
    1. Disassembly the adjusting screw.
    2.  
    3. Clean the adjusting screw threads with a wire brush, then wash all components with clean denatured alcohol.
    4.  
    5. Apply a suitable brake lubricant to the adjuster screw threads, the inside diameter of the socket and socket face.
    6.  
    7. You have achieved sufficient lubrication when a continuous bead of lubricant is on the end of the adjuster nut and the socket when the threads are fully engaged. Check the threads of the adjuster screw for smooth rotation over the full length.
    8.  

  6.  
  7. Install the spring clip in the same position from which it was removed.
  8.  

Do not stretch the lower return spring. The spring will be damaged if the extended length is greater than 3.88 in. (98.6mm).

  1. Install the lower return spring between the shoe and linings.
  2.  
  3. Install the adjuster shoe and lining and shoe and lining (after connecting the parking brake cable) with the hold-down pins and springs.
  4.  
  5. The lower return spring should be positioned under the anchor plate. For cable adjustment, refer to the procedure located in this section.
  6.  
  7. The adjuster shoe and lining is the one in which the adjuster pin was installed in the shoe web. Install the adjuster shoe and lining to the front of the car on the left side brake assembly or to the rear of the car on the right side brake assembly.
  8.  
  9. Install the adjusting screw assembly between the adjuster shoe and lining and the other shoe and lining on the backing plate. Proper assembly of the adjusting screw is with the adjuster screw engaging the notch in the adjuster shoe and lining and the spring clip pointing toward the backing plate.
  10.  
  11. Install the spring washer with the concave side against the web of the adjuster shoe and lining.
  12.  
  13. Position the adjuster actuator so that its top leg engages the notch in the adjuster screw (view C-C in the accompanying figure).
  14.  



Click image to see an enlarged view

Fig. Drum brake assembly special views A-A, B-B and C-C

  1. Install the spring connecting link and hold in place.
  2.  

Do not overstretch the upper return spring. The spring will be damaged if it is extended past 5.5 in. (140mm).

  1. Install the upper return spring. Insert the angled hook end of the spring through the parking brake lever and shoe/lining assembly (view A-A in the accompanying figure).
  2.  
  3. Grasp the long, straight section of the spring with suitable brake spring pliers. Pull the spring straight across and then down to hook into the crook on the spring connecting link.
  4.  

Do not overstretch the actuator spring. The spring will be damaged if it is stretched more than 3.27 in. (83mm).

  1. Install the actuator spring with suitable pliers. Position as shown in view B-B of the accompanying figure.
  2.  
  3. Check to make sure the parking brake lever is at its stop and that the brake shoes are properly centered on the wheel cylinder pistons.
  4.  
  5. Install the brake drum, then adjust the brakes, as outlined later in this section.
  6.  
  7. Install the wheel and tire assembly, then carefully lower the vehicle.
  8.  
  9. Tighten the wheel lug nuts to 100 ft. lbs. (136 Nm).
  10.  

Specific to:

Buick LeSabre 1991-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1991-1999

  1. Loosen the wheel lug nuts.
  2.  
  3. Raise and safely support the vehicle.
  4.  
  5. Matchmark the installed relationship of the wheel to the lug studs in the bearing flange, then remove the wheel and tire assembly.
  6.  
  7. Matchmark the position of the drum to the lug studs, then remove the brake drum.
  8.  
  9. Remove the actuator spring. Use a suitable brake spanner and removal tool to pry the loop end of the spring from the adjuster actuator, then disconnect from the web of the parking brake shoe.
  10.  



Click image to see an enlarged view

Fig. Use the brake spanner to remove the actuator spring

When removing the retractor spring from either shoe or lining, do not overstretch it. Overstretching reduces the spring's effectiveness.

  1. Lift the end of the retractor spring from the adjuster shoe and lining. Insert the hood end of the spanner tool between the retractor spring and the adjuster shoe web, and pry or twist to lift the end of the spring out of the shoe web hole.
  2.  



Click image to see an enlarged view

Fig. Disengage the retractor spring from the shoe and lining


CAUTION
Make sure to keep your fingers clear of the retractor spring to avoid pinching them between the spring and shoe web or spring and backing plate.

  1. Pry the end of the retractor spring toward the axle with the flat edge of the spanner tool until the spring snaps down off the shoe web onto the backing plate.
  2.  
  3. Remove the adjuster shoe and lining, adjuster actuator and adjusting screw assembly.
  4.  
  5. Disconnect the parking brake lever from the parking brake shoe and lining. Do not remove the parking brake cable from the lever, unless the lever is being replaced.
  6.  
  7. Lift the end of the retractor spring from the parking brake shoe and lining. Insert the hook end of the spanner tool between the retractor spring and parking brake shoe web, and pry or twist to lift the end of the spring out of the shoe web hole.
  8.  


CAUTION
Keep your fingers clear of the spring to avoid pinching them between the spring and shoe web or spring and backing plate.

  1. Pry the end of the retractor spring toward the axle with the flat edge of the spanner tool until the spring snaps down off the shoe web onto the backing plate.
  2.  
  3. Remove the parking brake shoe and lining. If only the shoes and linings are being replaced, the retractor spring does not have to be removed. Otherwise, remove the retractor spring from the anchor plate.
  4.  
  5. Clean all parts with denatured alcohol. Replace all parts that are questionable in strength or quality due to discoloration from heat, over-stress or wear.
  6.  
  7. Inspect the wheel cylinder for leakage, and cut or damaged boots.
  8.  



Click image to see an enlarged view

Fig. Exploded view of the drum brake components - 1991-99 vehicles

To install:

  1. Lubricate the following with suitable brake lubricant:
    1. Six raised shoe pads on the backing plate.
    2.  
    3. Anchor surfaces on the backing plate that contact the lower ends of the brake shoes.
    4.  

  2.  

When installing the retractor spring into either shoe and lining, do not overstretch it. Overstretching will reduce the spring's effectiveness.

  1. If the retractor spring was removed, reinstall it, hooking the center spring section under the tab on the anchor.
  2.  
  3. Install the parking brake shoe and lining, as follows:
    1. Position the shoe and lining on the backing plate.
    2.  
    3. Using brake spanner tool, pull the end of the retractor spring up to rest on the web of the brake shoe.
    4.  

  4.  



Click image to see an enlarged view

Fig. Pulling the spring end onto the shoe web

    1. Using the spanner tool, pull the end of the retractor spring over, until it snaps into the slot in the brake shoe.
    2.  




Click image to see an enlarged view

Fig. Using the brake tool to pull the spring end into the shoe slot

  1. Install the parking brake lever to the parking brake shoe and lining.
  2.  
  3. If disconnected, connect the parking brake cable to the lever.
  4.  
  5. Disassemble, clean and reassemble the adjusting screw, as follows:
    1. Disassembly the adjusting screw.
    2.  
    3. Clean the adjusting screw threads with a wire brush, then wash all components with clean denatured alcohol.
    4.  
    5. Apply a suitable brake lubricant to the adjuster screw threads, the inside diameter of the socket and socket face.
    6.  
    7. You have achieved sufficient lubrication when a continuous bead of lubricant is on the end of the adjuster nut and the socket when the threads are fully engaged. Check the threads of the adjuster screw for smooth rotation over the full length.
    8.  

  6.  



Click image to see an enlarged view

Fig. Exploded view of the adjusting screw assembly

  1. Install the adjusting screw assembly and adjuster shoe lining, as follows:
    1. Engage the pivot nut with the web of the parking brake shoe and lining in the parking brake lever, view A-A in the accompanying figure.
    2.  
    3. Position the adjuster shoe and lining so the shoe web engages the deep slot in the adjuster socket (view B-B in the accompanying figure).
    4.  

  2.  



Click image to see an enlarged view

Fig. Installed brake component views

  1. Install the retractor spring into the adjuster shoe and lining. Use the spanner tool to pull the end of the retractor spring up to seat on the web of the brake shoe, then pull the end of the retractor spring over until it snaps into the slot in the brake shoe.
  2.  
  3. Install the adjuster actuator, as follows:
    1. Lubricate the tab and pivot point on the adjuster actuator with suitable brake lubricant.
    2.  
    3. Using the spanner tool, spread the brake shoes while working the adjuster actuator into position.
    4.  

  4.  



Click image to see an enlarged view

Fig. Use the tool to spread the brake shoes for adjuster actuator installation

  1. Install the actuator spring, as follows:
    1. Engage the U-shaped end of the spring in the hole in the web of the parking brake shoe.
    2.  
    3. Use the spanner tool to stretch the spring and engage the loop end over the tab on the adjuster actuator.
    4.  

  2.  
  3. Check the following to be sure of proper positioning and function of the adjuster actuator:
    1. The adjuster actuator pivot in the shoe web slot.
    2.  
    3. The notch in the adjuster actuator on step in the adjusting screw notch.
    4.  
    5. Arm of the adjuster actuator resting freely on the star wheel under the teeth of the adjuster screw, not trapped under the teeth in a downward angle.
    6.  
    7. Install the spanner tool between the upper ends of the shoe and lining assemblies. Spread the shoes and watch for proper rotation of the star wheel.
    8.  

  4.  
  5. Adjust the service brakes and parking brakes.
  6.  
  7. Install the brake drum.
  8.  
  9. Install the wheel and tire assembly, then carefully lower the vehicle.
  10.  
  11. Tighten the wheel lug nuts to 100 ft. lbs. (136 Nm).
  12.  

 
label.common.footer.alt.autozoneLogo