Brake Caliper Rebuild - Rear

Complete rebuild of rear brake calipers including disassembly, cleaning, seal replacement, piston installation, and system bleeding to restore proper braking function.

Warnings

Tools required

Parts

• Rear brake caliper rebuild kit (seals, dust boots, pistons if damaged) × 2 — Use OEM Mopar or quality aftermarket kit for single-piston rear calipers
• Brake fluid DOT 3 × 1 — Mopar or equivalent DOT 3
• Copper crush washers for brake line banjo bolts (if applicable) × 4 — Check caliper brake line attachment style

Fluids

• brake — 1 qt

Preparation

1. Park vehicle on level surface and place wheel chocks at front wheels.
2. Verify you have a complete caliper rebuild kit for both rear calipers before beginning work.
3. Open brake fluid reservoir cap to vent system during caliper removal (DO NOT allow reservoir to run dry at any point).
4. Loosen rear wheel lug nuts while vehicle is on ground.
5. Raise rear of vehicle with floor jack and secure on jack stands at manufacturer-specified jacking points.
6. Remove both rear wheels and set aside.
7. Inspect brake rotors for excessive wear, scoring, or warping; replace if necessary before caliper rebuild.
8. Prepare clean workspace with brake parts cleaner, lint-free rags, and rebuild kit components laid out for inspection.

Procedure

1. 1

   Remove Rear Brake Caliper from Bracket
   Working on one side at first, locate the caliper mounting bolts that secure the caliper to the bracket. Remove these bolts completely and carefully slide the caliper off the rotor. Support the caliper; do not allow it to hang by the brake hose. If the caliper is seized on the rotor, gently work it free without prying against the rotor surface.
2. 2

   Disconnect Brake Line from Caliper
   Place a drain pan beneath the caliper. Using a brake line wrench (flare nut wrench) to prevent rounding, disconnect the brake line fitting from the caliper. If a banjo bolt is used, note the position of copper crush washers on each side of the fitting. Cap or plug the brake line immediately to minimize fluid loss and contamination. Allow caliper to drain completely into pan.
   ⚠Brake fluid will drain from the line and caliper. Have a catch pan ready and do not allow fluid to contact paint, rubber components, or skin.
3. 3

   Disassemble Caliper Body
   Take the caliper to your clean workspace. Remove the dust boot retaining clip (if present) and dust boot from the caliper body. Using controlled compressed air applied to the brake fluid inlet port, gently ease the pistons out of the caliper bores. Note: this is a fixed multi-piston caliper — pistons will move unevenly, so restrain the pistons that come out first (using spacers or clamps) so remaining pistons can be extracted, and use a rag to catch each piston as it exits. Use a rag to catch the piston as it exits to prevent damage. If compressed air is unavailable, use a plastic or wooden tool to carefully work the piston out by hand. Once piston is removed, extract the piston seal from the groove inside the caliper bore using a non-metallic pick or seal removal tool, being extremely careful not to scratch the bore surface.
   ⚠Use low air pressure (30-40 psi maximum) when using compressed air to remove piston. Excessive pressure can cause piston to eject violently, causing injury.
   ⚠Never use metal tools inside the caliper bore. Any scratches or damage to the bore surface will cause seal leakage and caliper failure.
4. 4

   Inspect and Clean Caliper Components
   Thoroughly inspect the caliper bore for pitting, scoring, corrosion, or damage. Minor surface corrosion can be removed with a brake cylinder hone; deep pitting requires caliper replacement. Inspect the piston for scoring, corrosion, or chrome plating damage; replace if any defects are present (most rebuild kits include new pistons). Clean all caliper passages, bore, and exterior surfaces with brake parts cleaner and compressed air. Ensure all old seal material and debris is completely removed from the seal groove. Clean the piston with brake parts cleaner and dry with lint-free cloth.
   ℹ️The caliper bore must be perfectly smooth and free of any pitting or scoring for proper seal function. When in doubt, replace the caliper rather than risk seal failure.
5. 5

   Install New Piston Seal
   Verify the new piston seal from the rebuild kit matches the old seal in size and profile. Lubricate the new piston seal lightly with clean brake fluid from a fresh sealed container. Carefully install the seal into the groove in the caliper bore, ensuring it seats completely and evenly around the entire circumference without twisting or rolling. Run your finger around the seal to confirm it is fully seated in the groove with no high spots.
   ⚠Use only clean brake fluid as lubricant for seals. Never use petroleum-based products, which will destroy rubber brake components immediately.
6. 6

   Install Piston into Caliper Bore
   Lubricate the piston outer surface and caliper bore lightly with clean brake fluid. Carefully align the piston squarely with the bore opening. Using steady, even hand pressure or a C-clamp with a smooth protective block, push the piston straight into the bore, ensuring it does not cock or bind. Press the piston fully to the bottom of the bore. The piston should move smoothly without excessive force; if significant resistance is encountered, remove and inspect for seal misalignment or bore obstruction.
   ⚠The piston must enter the bore perfectly straight. Cocking the piston during installation can damage the new seal or piston, causing immediate failure.
7. 7

   Install Dust Boot
   Lubricate the new dust boot lightly with clean brake fluid. Stretch the inner lip of the dust boot over the groove on the piston, ensuring it seats completely. Then seat the outer edge of the boot into the groove on the caliper body, working around the circumference until fully seated. Install the dust boot retaining clip (if applicable) to secure the boot. Inspect the boot to ensure it is not twisted and forms a complete seal around both piston and caliper body.
   ℹ️The dust boot prevents contamination of the caliper bore and seal. A properly seated boot is critical for long-term caliper function.
8. 8

   Clean and Inspect Caliper Mounting Hardware
   While the caliper is removed, thoroughly clean the caliper bracket and all mounting surfaces with a wire brush and brake parts cleaner. Note: the 1992 Viper uses fixed multi-piston calipers, which do not have slide pins. Inspect all mounting surfaces and hardware for wear, corrosion, or damage and replace if necessary.ign uses them.
   Torque spec

   Caliper Slide Pin Bolts35 Nm (26 lb-ft)
9. 9

   Reinstall Caliper and Connect Brake Line
   Position the rebuilt caliper over the brake rotor and align with mounting points on the bracket. Install caliper mounting bolts and tighten to specification using a calibrated torque wrench. Apply medium-strength threadlocker to caliper bolt threads before installation. Reconnect the brake line to the caliper. Verify the fitting style used on the Viper caliper (banjo bolt vs. inverted flare); if a banjo bolt is used, install a new copper crush washer on each side of the fitting. Tighten the brake line fitting to specification using a brake line wrench.
   ⚠️Caliper mounting bolts are CRITICAL safety fasteners. Use a calibrated torque wrench and verify proper torque. Under-torqued bolts can allow caliper separation; over-torqued bolts can fail.
10. 10

    Repeat Procedure for Opposite Side
    Perform steps 1 through 9 for the opposite rear caliper, using the same careful procedures. Maintain the same quality standards for cleaning, inspection, and assembly. Ensure both calipers are rebuilt to identical specifications.
    ℹ️Both rear calipers must be rebuilt to ensure balanced brake performance. Do not leave one side with old seals.
11. 11

    Bleed Rear Brake System
    Fill the brake fluid reservoir to the MAX line with fresh DOT 3 brake fluid. Starting with the rear caliper furthest from the master cylinder (typically right rear), attach a clear hose to the bleeder screw and submerge the other end in a container with clean brake fluid. Have an assistant slowly depress the brake pedal while you open the bleeder screw approximately 1/2 turn. Close the bleeder before the assistant releases the pedal. Repeat until fluid flows without air bubbles. Tighten bleeder screw to specification. Repeat for the other rear caliper. Check reservoir level frequently and never allow it to run dry during bleeding.
    ⚠️Air in the brake system will cause partial or complete brake failure. Bleeding must be thorough and complete before operating the vehicle.
    ⚠Never reuse brake fluid captured during bleeding. Always dispose of old brake fluid properly according to local regulations.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
12. 12

    Perform Final System Check
    With the engine off, pump the brake pedal several times until firm pedal resistance is felt. Pedal should become progressively firmer and hold steady pressure without sinking. Inspect all brake line connections and caliper fittings for leaks while pressure is applied. Check brake fluid reservoir level and top off to MAX line if needed. Wipe all caliper and line fittings clean and inspect again after 30 seconds for any seepage. If pedal remains soft or sinks, repeat bleeding procedure.
    ⚠️A soft or spongy brake pedal indicates air remains in the system or a seal failure. Do NOT drive the vehicle until a firm, solid pedal is achieved.
13. 13

    Reinstall Wheels and Perform Rolling Test
    Reinstall both rear wheels and hand-tighten lug nuts in a star pattern. Lower vehicle to ground and torque lug nuts to specification in a star pattern using a calibrated torque wrench. Before driving at speed, perform a low-speed test in a safe area: drive forward slowly and apply brakes gently, then with increasing firmness. Brakes should engage smoothly and evenly without pulling to either side. Check for any unusual noises, vibrations, or fluid leaks. Re-inspect all connections and torque specifications.
    ⚠️The first brake application after caliper rebuild may have reduced effectiveness as pistons seat. Perform initial test stops at very low speed in a controlled environment with no traffic.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Reassembly is covered in the procedure steps above, with all components installed in reverse order of removal.
2. All torque specifications must be followed precisely using a calibrated torque wrench.
3. Only fresh DOT 3 brake fluid from sealed containers should be used.
4. Complete bleeding of both rear calipers is mandatory before vehicle operation.

Verification

• Brake pedal must be firm and hold steady pressure without sinking when engine is off.
• No brake fluid leaks visible at any caliper body, piston, or line connection after applying pedal pressure.
• Vehicle brakes evenly in straight line during test stops with no pull to either side.
• Brake fluid reservoir is at proper MAX level with reservoir cap properly sealed.
• All caliper mounting bolts and brake line fittings verified at proper torque specification.
• No unusual noises, grinding, or rubbing from rear brakes during test drive.
• Rear brake calipers do not exhibit excessive heat after moderate braking (compare to front caliper temperature; all should be similar).
• After 50-100 miles of normal driving, re-inspect all brake connections for any seepage and verify pedal remains firm.

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