This procedure covers the complete disassembly, inspection, cleaning, and rebuild of the rear brake calipers on a 2012-2018 Jeep Wrangler with the 3.6L V6 engine, including seal replacement and bleeding.

Warnings

Tools required

Parts

• Rear brake caliper rebuild kit (includes seals, dust boots, and O-rings) × 2 — Use OEM Mopar kit or quality aftermarket
• Brake caliper assembly grease (high-temp silicone) × 1 — Included in most rebuild kits
• Thread locker (medium strength) × 1 — Loctite 242 or equivalent
• Brake cleaner solvent × 1 — Non-chlorinated preferred
• Copper crush washers for brake line (if applicable) × 2 — Use OEM specification

Fluids

• Mopar DOT 4 Brake Fluid — 1 qt

Preparation

1. Park vehicle on level ground and set parking brake. Place wheel chocks at front wheels.
2. Remove approximately half the brake fluid from master cylinder reservoir using turkey baster or syringe. Dispose of properly.
3. Loosen rear wheel lug nuts while vehicle is on ground (do not remove).
4. Raise rear of vehicle using floor jack and support securely on jack stands placed at factory lift points on frame rails.
5. Remove rear wheels completely.
6. Verify caliper rebuild kits contain all necessary seals, boots, and O-rings for your specific caliper model.
7. Prepare clean workspace with all tools and parts laid out. Ensure compressed air source is available.
8. Have brake fluid catch container ready beneath work area.

Procedure

1. 1

   Remove brake caliper from mounting bracket
   Place drain pan beneath caliper. Using line wrench, carefully loosen brake line fitting at caliper. Once loose, unthread completely by hand and immediately plug open line with clean rubber cap or tape to prevent fluid loss and contamination. Remove caliper mounting bolts (guide pin bolts) and lift caliper off rotor and bracket. Support caliper on clean work surface.
   ⚠Use only a line wrench on brake line fittings. Standard wrenches will round off the soft brass fittings.
   Torque spec

   Line Fittings23 Nm (17 lb-ft)
2. 2

   Inspect caliper exterior and prepare for disassembly
   Clean exterior of caliper thoroughly with brake cleaner and wire brush, removing all dirt, rust, and debris. Inspect caliper body for cracks, deep scoring, or damage. If caliper body is damaged, replacement rather than rebuild is required. Remove bleeder screw cap and verify bleeder screw operates freely (do not remove yet).
3. 3

   Remove caliper piston using compressed air
   Place caliper in padded vise or on protected work surface with piston facing up. Place a shop rag or wooden block in front of piston to catch it. Connect compressed air nozzle to brake line inlet port or bleeder screw hole. Apply short bursts of compressed air (40-60 psi) to hydraulically eject piston from bore. Keep fingers and face clear of piston path. If piston is severely stuck, you may need to apply penetrating oil around piston edge and wait 30 minutes before attempting air removal again.
   ⚠️Keep hands and face away from piston during air ejection. Use only enough air pressure to move piston - excessive pressure can cause piston to eject violently.
4. 4

   Remove seals and inspect caliper bore
   Remove dust boot from caliper bore groove using pick or small screwdriver. Remove piston seal from bore groove using pick, being extremely careful not to scratch caliper bore surface. Remove all O-rings from fluid passages. Inspect caliper bore for scoring, pitting, or corrosion. Minor surface rust can be cleaned with fine abrasive (crocus cloth), but deep scoring or pitting requires caliper replacement. Measure bore diameter if micrometer available - compare to service specification.
   ⚠Do not use sharp metal tools that could damage the precision-machined caliper bore. Scratches in the bore will cause leaks and seal failure.
5. 5

   Inspect and measure piston
   Clean piston thoroughly with brake cleaner. Inspect piston surface for scoring, pitting, or chrome plating damage. Check piston for straightness by rolling on flat surface. Measure piston outer diameter if measuring tools available. Any damage to piston surface requires piston replacement (included in some rebuild kits, otherwise source separately). Minor corrosion can be polished with fine crocus cloth only.
6. 6

   Clean all caliper components
   Thoroughly clean caliper bore, piston, and all fluid passages using brake cleaner and lint-free rags. Use compressed air to blow out all passages and dry components completely. Inspect bleeder screw threads and ensure passage is clear. All components must be completely clean and dry before assembly - any contamination will cause premature seal failure.
7. 7

   Install new piston seal
   Coat new piston seal lightly with fresh DOT 4 brake fluid or brake assembly grease from rebuild kit. Carefully install seal into caliper bore groove using only your fingers - never use tools that could damage the seal. Ensure seal is seated evenly in groove all the way around with no twists or folds. Seal should sit below bore surface.
   ⚠Use only brake fluid or the specific grease provided in the rebuild kit. Never use petroleum-based lubricants which will destroy rubber seals.
8. 8

   Install dust boot on piston
   Coat piston outer surface lightly with brake fluid or assembly grease. Install new dust boot onto piston first, seating it in the piston groove. Ensure boot is properly positioned in piston groove before installation into bore. Some designs require boot installation after piston installation - follow rebuild kit instructions for your specific caliper design.
9. 9

   Install piston into caliper bore
   Coat caliper bore lightly with brake fluid. Carefully align piston squarely with bore opening. Using gentle hand pressure or C-clamp with wooden block, slowly push piston into bore, ensuring it does not cock or bind. Piston should slide in smoothly with even resistance. Once piston is fully seated, seat dust boot outer lip into caliper body groove, ensuring it is not twisted or pinched.
   ⚠Never force piston into bore. Binding indicates misalignment or seal damage. Remove and inspect if resistance is uneven.
10. 10

    Install new O-rings and bleeder screw
    Install new O-rings on all fluid passage connections (if applicable to your caliper design). Lubricate O-rings with brake fluid. Clean bleeder screw threads and apply small amount of anti-seize or brake fluid to threads (not thread locker). Install bleeder screw hand-tight, then torque to specification.
    Torque spec

    Bleeder Screw16 Nm (12 lb-ft)
11. 11

    Install rebuilt caliper onto vehicle
    Remove plugs from brake line. Install new copper crush washers on brake line fitting if applicable. Position caliper over rotor and align with mounting bracket. Apply medium-strength thread locker to caliper mounting bolt threads. Install and hand-start caliper mounting bolts, then torque to specification. Connect brake line to caliper using line wrench and torque fitting to specification.
    ℹ️Ensure brake pads are properly positioned and caliper slides freely on guide pins before final tightening.
    Torque spec

    Caliper Bolts102 Nm (75 lb-ft)

    Line Fittings23 Nm (17 lb-ft)
12. 12

    Bleed rear brake caliper
    Fill master cylinder to MAX line with fresh DOT 4 brake fluid. Attach clear bleeding hose to bleeder screw with other end submerged in clean brake fluid in catch container. Have assistant slowly depress brake pedal to floor and hold. Open bleeder screw 1/2 turn - fluid and air will flow into hose. Close bleeder screw before assistant releases pedal. Repeat process until no air bubbles appear in hose and only clean fluid flows. Tighten bleeder screw to specification on final cycle. Keep master cylinder filled throughout process.
    ⚠Never allow master cylinder to run dry during bleeding or air will enter the ABS system requiring professional scan tool bleeding.
    Torque spec

    Bleeder Screw16 Nm (12 lb-ft)
13. 13

    Repeat procedure for opposite side
    Perform steps 1-12 for the other rear caliper. Always rebuild and bleed both rear calipers during this service to ensure balanced braking performance. Maintain symmetry in parts and procedures between left and right sides.
14. 14

    Final brake system bleeding and pedal check
    After both rear calipers are rebuilt and individually bled, perform complete brake system bleeding starting from wheel farthest from master cylinder (right rear, left rear, right front, left front). Top off master cylinder to MAX line with fresh DOT 4 brake fluid. With engine off, pump brake pedal several times - pedal should become firm. If pedal remains soft, additional bleeding is required.
15. 15

    Install wheels and perform final torque
    Install rear wheels and hand-start all lug nuts. Lower vehicle until wheels just contact ground (still supported by jack). Torque lug nuts to specification in star pattern. Fully lower vehicle and remove jack stands. Torque lug nuts again in star pattern to verify proper torque.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)

Reassembly

1. Verify all caliper mounting bolts are torqued to specification and thread locker has been applied
2. Confirm brake lines are properly connected and torqued with no leaks visible
3. Check that dust boots are properly seated in both piston and caliper body grooves
4. Ensure master cylinder is filled to MAX line with fresh DOT 4 brake fluid
5. Verify bleeder screws are closed and dust caps installed
6. Double-check all lug nuts are torqued in proper star pattern

Verification

• With engine running, pump brake pedal several times - pedal should feel firm and not sink to floor
• Start engine and verify brake warning light is not illuminated on instrument cluster
• Inspect all brake line connections and caliper areas for any fluid leaks
• Test drive vehicle in safe area at low speed - verify brakes engage smoothly without pulling to one side
• Perform several moderate stops from 30 mph to verify proper braking force and pedal feel
• After test drive, re-inspect all connections for leaks and verify master cylinder fluid level
• Road test at highway speeds only after confirming proper operation in controlled environment
• Check brake pedal travel - should be approximately 1/3 to 1/2 pedal travel for full stop
• Listen for any unusual noises during braking which could indicate improper assembly

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