Brake Caliper Rebuild - Rear

Complete disassembly, inspection, cleaning, seal replacement, and reassembly of rear disc brake calipers on a 1966 Corvette with four-wheel disc brakes.

Warnings

Tools required

Parts

• Rear brake caliper rebuild kit (includes pistons, seals, dust boots, and retaining rings) × 2 — Use OEM specification or equivalent for 1966 Corvette rear caliper
• Brake caliper mounting bolts (if corroded) × 4 — Use OEM specification
• Copper crush washers for brake line banjo bolts × 2 — Use OEM specification
• Brake cleaner spray × 2 — Non-chlorinated brake parts cleaner
• Brake assembly lubricant (silicone-based) × 1 — Compatible with DOT 4 brake fluid

Fluids

• DOT 4 Brake Fluid — 1 qt

Preparation

1. Park vehicle on level, solid surface and apply parking brake firmly
2. Place wheel chocks in front of front wheels
3. Loosen rear wheel lug nuts 1/2 turn while vehicle is on ground
4. Raise rear of vehicle using floor jack at rear differential or frame contact points
5. Support vehicle securely on jack stands placed under rear frame rails - never work under a vehicle supported only by a jack
6. Remove rear wheels completely
7. Verify jack stands are stable and vehicle cannot roll or fall
8. Locate a clean workspace to disassemble calipers with adequate lighting
9. Arrange clean rags or paper to lay out parts in order of removal for reassembly reference
10. Have brake fluid catch containers ready under work area

Procedure

1. 1

   Remove right rear caliper assembly
   Working on the right rear wheel first, use a brake bleeder wrench to open the bleeder screw on the caliper and allow brake fluid to drain into a catch container. Close the bleeder. Using a flare-nut wrench, carefully loosen and remove the brake line banjo bolt from the rear of the caliper, allowing remaining fluid to drain. Immediately plug the brake line with a rubber cap or plug to prevent fluid loss and contamination. Remove the two caliper mounting bolts securing the caliper to the spindle mounting bracket. Carefully lift the caliper assembly off the brake rotor and set on a clean work surface. Do not allow the caliper to hang by the brake line if line is still attached.
2. 2

   Inspect caliper exterior and rotor condition
   Before disassembly, visually inspect the caliper body for cracks, excessive corrosion, or damage. Check the brake rotor surface for deep scoring, excessive wear, or heat cracks. If the caliper body is cracked or severely corroded, it must be replaced rather than rebuilt. Note the thickness and condition of brake pads for reference. Measure rotor thickness with a micrometer if available and compare to service limit specifications (nominal thickness 1.250", minimum 1.230").
3. 3

   Remove brake pads and hardware
   Remove the brake pad retaining pins or clips (configuration varies by specific caliper design on 1966 Corvette rear). Carefully note the orientation and position of all springs, clips, and shims for reassembly. Slide the brake pads out of the caliper housing. Remove any anti-rattle springs or pad support hardware. Place all hardware in order on your clean workspace.
4. 4

   Remove pistons from caliper
   Place the caliper in a padded vice or secure it on the workbench with rags underneath to catch brake fluid. To extract the piston, use either compressed air or a piston removal tool. If using compressed air, attach an air nozzle to the brake line inlet port (where the banjo bolt was removed) and apply LOW pressure (20-30 psi maximum) gradually while holding a rag over the piston to control its movement. The piston will slowly push out. NEVER use high pressure or allow the piston to shoot out uncontrolled. Alternatively, use a piston extraction tool designed for brake calipers. Remove the piston completely and set aside for inspection.
5. 5

   Remove seals and dust boots
   Using a small wooden or plastic pick (never metal that can scratch the bore), carefully pry out the dust boot retaining ring from its groove in the caliper bore. Remove the dust boot completely. Locate the piston seal (square-section O-ring) seated in a groove inside the caliper bore. Carefully extract this seal using the pick, taking extreme care not to scratch or gouge the bore surface. Any scratches in the bore will cause fluid leaks and caliper failure. Remove all old seals and set aside for disposal.
6. 6

   Clean and inspect caliper bores
   Thoroughly clean the caliper bore and all internal passages using brake cleaner spray and lint-free rags. Use a soft wire brush on external surfaces only. Inspect the bore surface for scoring, pitting, or corrosion. Light surface rust or staining can be removed with crocus cloth (very fine abrasive) or a brake cylinder hone, working in a rotating motion with brake fluid as lubricant. The bore must be smooth and free of pits or scratches deeper than 0.002". If damage exceeds this, the caliper must be replaced or professionally re-sleeved. Clean all brake fluid passages with compressed air. Dry the bore completely with clean compressed air.
7. 7

   Inspect and clean pistons
   Clean each piston thoroughly with brake cleaner and inspect for scoring, pitting, corrosion, or wear. The piston surface must be smooth and chrome plating (if applicable) must be intact without flaking or pitting. Check piston diameter with a micrometer if available - any wear beyond 0.003" requires piston replacement. Most rebuild kits include new pistons; use them if there is any doubt about the old piston condition. Clean piston and dry with compressed air.
8. 8

   Install new piston seals
   Coat your fingers with fresh brake fluid from a sealed container. Remove the new piston seal (square-section O-ring) from the rebuild kit and lubricate it thoroughly with brake fluid. Locate the seal groove inside the caliper bore (it is the inner groove, closer to the bottom of the bore). Carefully work the seal into this groove using only your fingers, ensuring it seats completely around the entire circumference without twisting or rolling. The seal must sit flat in its groove with no kinks or overlaps.
9. 9

   Install pistons
   Generously lubricate the new or cleaned piston with fresh brake fluid. Lubricate the caliper bore surface with brake fluid. Carefully align the piston squarely with the bore opening and push it in by hand, using a twisting motion to help it pass over the seal. Push the piston approximately 1/4" into the bore past the seal - it should move smoothly without binding. Do not force it. If resistance is felt, remove the piston, check seal installation, and re-lubricate.
10. 10

    Install dust boots and retaining hardware
    Take the new dust boot from the rebuild kit and fit the inner lip into the groove on the piston itself. Stretch the outer portion of the boot over the caliper bore opening and seat it into the outer groove in the caliper body. Install the dust boot retaining ring into its groove, ensuring the boot is captured properly all around and not twisted or pinched. The boot should form a complete seal around both the piston and caliper bore.
11. 11

    Repeat rebuild process on left rear caliper
    Remove the left rear caliper assembly following the same procedure as Step 1. Perform the complete rebuild procedure (Steps 2-10) on the left rear caliper, working carefully and methodically. Having the first caliper completed provides a reference if any questions arise about assembly sequence.
12. 12

    Reinstall right rear caliper assembly
    Clean the caliper mounting surfaces on the spindle bracket with a wire brush. If the original caliper mounting bolts show corrosion or damaged threads, replace them with new bolts. Position the rebuilt right rear caliper over the brake rotor and align the mounting holes with the bracket. Install the caliper mounting bolts and torque to specification (35-45 ft-lbs typical for 1966 Corvette rear calipers, verify with factory service manual). Install new copper crush washers on the brake line banjo bolt, position the brake line to the caliper inlet, and install the banjo bolt finger-tight only at this stage.
13. 13

    Reinstall left rear caliper assembly
    Following the same procedure as Step 12, reinstall the rebuilt left rear caliper assembly with new mounting bolts if needed, torque mounting bolts to specification, and connect the brake line with new copper washers on the banjo bolt (finger-tight only).
14. 14

    Bleed rear brake system - right side
    Fill the master cylinder reservoir with fresh DOT 4 brake fluid to the MAX line. Have an assistant sit in the driver's seat. Connect a clear plastic hose to the right rear caliper bleeder screw and submerge the other end in a container partially filled with brake fluid. Have the assistant slowly pump the brake pedal 5-6 times and hold pressure. Open the bleeder screw 1/2 turn while your assistant maintains pedal pressure - fluid and air will discharge through the hose. Close the bleeder before the assistant releases the pedal. Repeat this process until fluid flows with no air bubbles. Keep master cylinder reservoir topped off throughout the process. When bleeding is complete, tighten the bleeder screw to 80-100 inch-lbs. Torque the brake line banjo bolt to 18-22 ft-lbs.
15. 15

    Bleed rear brake system - left side
    Following the identical procedure as Step 14, bleed the left rear caliper until all air is purged and only clean bubble-free brake fluid emerges. Tighten bleeder screw to 80-100 inch-lbs. Torque the brake line banjo bolt to 18-22 ft-lbs. Top off master cylinder reservoir to MAX line with DOT 4 brake fluid and install reservoir cap.
16. 16

    Perform final brake system function test
    With the vehicle still safely supported on jack stands, have an assistant pump the brake pedal slowly 15-20 times to seat the pistons against the pads. The pedal should become firm and not sink to the floor. Check all bleeder screws and brake line connections for leaks. Inspect under each caliper for any signs of fluid seepage. Reinstall both rear wheels and torque lug nuts to 70-80 ft-lbs in a star pattern. Lower the vehicle to the ground and perform additional pedal pumping. Test brake pedal feel - it should be firm with approximately 1-2 inches of free play before resistance.

Reassembly

1. Ensure all caliper mounting bolts are torqued to specification (verify exact torque in factory service manual)
2. Verify brake line banjo bolts are torqued properly with new copper washers installed
3. Double-check that all bleeder screws are closed and tight
4. Confirm master cylinder is filled to MAX line with fresh DOT 4 fluid
5. Verify wheel lug nuts are torqued to 70-80 ft-lbs in star pattern

Verification

• With vehicle still on jack stands, have assistant apply firm brake pedal pressure - rear wheels should resist rotation
• Inspect all caliper areas, bleeder screws, and brake line connections for any signs of fluid leakage
• Pump brake pedal 20-30 times and verify pedal remains firm and does not sink - a sinking pedal indicates air in the system or internal leakage
• After lowering vehicle, perform careful low-speed test drive in safe area (empty parking lot) - verify brakes engage smoothly without pulling to one side
• Perform moderate brake application from 20-30 mph and verify straight-line stopping with no pulsation or noise
• After test drive, re-inspect all connections for leaks while system is under pressure
• Check brake pedal feel after cooling period - it should remain firm
• Re-check master cylinder fluid level after test drive and top off if needed
• Plan to re-inspect all connections and fluid level after 50-100 miles of driving

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