Replace drum brake hardware kit (springs, adjusters, hold-down clips) on rear drum brakes to restore proper brake operation and safety.

Warnings

Tools required

Parts

• Drum brake hardware kit (rear, includes springs, adjusters, hold-downs) × 2 — Use OEM specification or equivalent (ACDelco 18K777 or similar)
• Brake drum (if worn beyond service limit) × 2 — Use OEM specification

Fluids

• DOT 4 Brake Fluid — 0.5 qt

Preparation

1. Park vehicle on level, solid surface and engage parking brake firmly
2. Chock front wheels securely on both sides
3. Loosen rear wheel lug nuts 1/2 turn while vehicle is on ground
4. Raise rear of vehicle with floor jack at rear axle differential housing
5. Place jack stands under rear axle tubes near differential, ensuring stable contact
6. Lower vehicle weight onto jack stands and verify stability before proceeding
7. Remove rear wheels completely and set aside
8. Release parking brake to allow drums to rotate freely

Procedure

1. 1

   Remove brake drum (first side)
   Attempt to pull the brake drum straight off the axle hub. If drum is stuck due to brake shoe adjustment or rust, thread two 3/8-16 bolts into the threaded holes on the drum face to push the drum off evenly. If drum still resists, tap gently around the outer edge with a rubber mallet. Once removed, hang drum aside and inspect inner friction surface for scoring, cracks, or excessive wear.
2. 2

   Document and clean brake assembly
   Take a detailed photograph of the entire brake assembly showing spring positions and hardware arrangement. This is critical for correct reassembly. Spray the entire brake assembly thoroughly with non-chlorinated brake cleaner, wiping away dust and debris with shop towels. Never use compressed air to blow brake dust. Allow assembly to dry completely before proceeding.
3. 3

   Remove upper return springs
   Using brake spring pliers, grasp the primary upper return spring (the spring connecting the top of the leading and trailing shoes) and unhook it from both brake shoes. The 1966 Corvette rear drums use a dual return spring design. Remove the secondary return spring in the same manner. Set springs aside and inspect for stretching, corrosion, or heat damage.
4. 4

   Remove brake shoe hold-down springs
   Each brake shoe is held to the backing plate by a hold-down spring assembly consisting of a pin, spring, and retainer cup. From the front of the backing plate, press in on the retainer cup while rotating it 90 degrees to align the slot with the pin head. Release pressure and remove the cup, spring, and pin. Repeat for both brake shoes (total of 2 hold-down assemblies per drum).
5. 5

   Disconnect parking brake cable and remove trailing shoe
   Locate the parking brake lever attached to the trailing (rear) brake shoe. Using needle-nose pliers, compress the cable return spring and unhook the parking brake cable from the lever. Remove the lower return spring connecting the bottom of both shoes using brake spring pliers. Lift the trailing shoe away from the backing plate, noting the position of the automatic adjuster mechanism.
6. 6

   Remove leading shoe and adjuster mechanism
   Remove the leading (front) brake shoe from the backing plate. Disassemble the adjuster mechanism, which consists of an adjuster cable, cable guide, adjuster lever, adjuster spring, and threaded star wheel adjuster. Inspect all components for wear, corrosion, or damage. The star wheel should turn freely without binding.
7. 7

   Inspect backing plate and wheel cylinder
   With shoes removed, inspect the backing plate for cracks, warping, or excessive rust. Check the wheel cylinder for signs of brake fluid leakage (wetness or staining around the dust boots). Gently pull back each dust boot; any fluid present indicates a leaking wheel cylinder that must be replaced before proceeding. Clean the backing plate ledges where shoes contact with wire brush and wipe with brake cleaner.
8. 8

   Prepare and lubricate new hardware
   Unpack the new drum brake hardware kit. Apply a thin coating of high-temperature brake lubricant (included in most kits or use synthetic brake grease) to the six backing plate contact points where the brake shoe webs rest. Do NOT get lubricant on friction surfaces. Lubricate the threads and socket end of the new star wheel adjuster and verify it turns smoothly.
9. 9

   Install leading shoe and adjuster components
   Position the leading brake shoe on the backing plate, engaging the top into the wheel cylinder piston slot and the bottom into the anchor. Install the hold-down pin from behind the backing plate, then install the spring and retainer cup, pressing in and rotating 90 degrees to lock. Install the adjuster cable guide to the anchor pin. Attach the star wheel adjuster mechanism to the leading shoe, with the star wheel toward the rear and the adjuster lever positioned correctly.
10. 10

    Install trailing shoe and connect parking brake
    Position the trailing shoe with parking brake lever attached, engaging it into the wheel cylinder piston slot (top) and anchor (bottom). Ensure the star wheel adjuster engages the trailing shoe web correctly. Install the hold-down pin, spring, and retainer cup. Using needle-nose pliers, stretch and hook the parking brake cable back onto the parking brake lever, ensuring proper seating.
11. 11

    Install return springs and adjuster components
    Install the lower return spring connecting the bottoms of both shoes using brake spring pliers. Install the adjuster spring between the adjuster lever and leading shoe. Route the adjuster cable over the cable guide and hook it to the adjuster lever. Install the upper return springs: first the primary spring, then the secondary spring, ensuring both are properly seated in the shoe webbing holes. Verify the adjuster mechanism moves freely when the trailing shoe is pulled outward.
12. 12

    Verify assembly and adjust brakes
    Verify all springs are correctly installed by comparing to your reference photo. Check that shoes move outward freely and return when released. Using a brake spoon or adjusting tool through the backing plate adjustment slot, rotate the star wheel adjuster to expand the shoes until the drum will just barely slide over them with slight drag. Back off the adjuster 8 clicks to provide proper clearance.
13. 13

    Install drum and repeat for opposite side
    Clean the inside of the brake drum with brake cleaner. Slide the drum onto the hub, ensuring it seats fully against the hub flange. If drum is tight, back off the star wheel adjuster slightly. With the first side complete, repeat steps 1 through 13 for the opposite rear wheel, using the completed side and your photos as reference.
14. 14

    Install wheels and perform initial brake adjustment
    Install both rear wheels and hand-tighten lug nuts in a star pattern. Raise vehicle slightly with floor jack, remove jack stands, and lower vehicle to ground. Torque lug nuts to approximately 65-70 ft-lbs in a star pattern (verify against factory specification). Start engine and pump brake pedal slowly 15-20 times to seat brake shoes and activate automatic adjusters. Check brake pedal feel; it should be firm within the top third of pedal travel.
15. 15

    Test parking brake and perform final checks
    With engine running, apply parking brake firmly. Attempt to move vehicle forward in gear; parking brake should hold vehicle securely. If parking brake is weak, minor cable adjustment may be needed at the front cable adjuster under the vehicle. Check brake fluid reservoir level and top off with DOT 3 (or compatible DOT 4) brake fluid if needed. Test drive in a safe area at low speed to verify proper brake operation before returning to normal service.

Reassembly

1. Work on one side at a time, using the opposite side as a reference to ensure correct spring and hardware placement
2. Compare completed assembly to reference photos before installing drum to catch any errors
3. Ensure parking brake cables are properly reconnected and not binding
4. Verify adjuster mechanisms operate freely and are positioned correctly (star wheel toward rear of vehicle)
5. All return springs must be fully seated in shoe webbing holes, not on shoe edges

Verification

• Brake pedal should be firm and engage within top third of pedal travel after pumping 15-20 times
• No brake fluid leaks present at wheel cylinders or brake lines
• Parking brake holds vehicle securely on a grade when fully engaged
• Both rear wheels rotate freely with no dragging or rubbing when brakes are released
• Test drive at low speed: brakes should apply smoothly and evenly without pulling to one side
• No unusual noises (squeaking, grinding, rattling) from rear brakes during operation
• Perform full-stop tests from 15-20 mph in safe area; vehicle should stop straight without pulling

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