Rebuild the rear brake calipers on a 2024 Model 3 Long Range AWD by disassembling the caliper, replacing the piston seal, dust boot, and slide pin boots, and reassembling with fresh DOT 4 brake fluid. The rear calipers also house the integrated parking brake actuator, which complicates this job versus a typical floating caliper rebuild.

Warnings

Tools required

Parts

• Rear caliper rebuild kit (piston seal, dust boot, bleeder cap) × 2 — Manufacturer-specified rear caliper seal kit for 2024 Model 3
• Caliper slide pin boot kit × 2 — OEM rear slide pin boot/bushing kit
• Brake pads (recommended if reassembling worn system) × 1 — OEM rear brake pad set
• Copper crush washers for banjo fitting (if equipped) × 4 — OEM-spec crush washer

Fluids

• DOT 4 brake fluid (Tesla-specified) — 1 qt

Preparation

1. Park on level ground, place in P, engage parking brake (it will need to be released electronically later — see EPB step).
2. Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
3. Disconnect the 12V low-voltage battery. On 2024 Model 3, this is typically located behind the right rear seat back panel; some 2024+ units use a lithium 12V under the floor — verify before cutting power.
4. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal.
5. If at any point you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
6. Before disconnecting the 12V, use a diagnostic tool to place the EPB into service/maintenance mode so the rear caliper pistons can be retracted.
7. Loosen rear lug nuts while the vehicle is on the ground.
8. Raise the rear of the vehicle using only the manufacturer-specified jacking points with rubber pucks to protect the battery pack.
9. Remove rear wheels.

Procedure

1. 1

   Place EPB in service mode
   With the diagnostic tool connected and the vehicle awake, command the rear EPB actuators to the service/open position. Confirm both rear actuators have fully retracted before disconnecting 12V power. Failing to do this will leave the piston locked and prevent caliper disassembly.
   ⚠️Do not attempt to manually back-drive the EPB actuator with hand tools — internal gearing will be damaged.
2. 2

   Disconnect EPB actuator harness
   Locate the EPB motor connector on the rear of the caliper. Release the locking tab and disconnect. Free the harness from any retainers on the caliper body so the caliper can be moved without straining the wiring.
3. 3

   Disconnect brake hydraulic line
   Place a drain pan beneath the caliper. Using a line wrench, loosen the hydraulic line fitting at the caliper. Cap the line immediately to prevent fluid loss and contamination. If a banjo fitting is used, discard the crush washers.
   ⚠Use a line wrench only — open-end wrenches will round the fitting.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
4. 4

   Remove caliper from bracket
   Remove the two caliper slide pin bolts securing the caliper to the bracket. Slide the caliper off the pads and bracket. Remove the brake pads and inspect the bracket abutment clips.
   Torque spec

   Caliper Slide Pin Bolts35 Nm (26 lb-ft)
5. 5

   Remove caliper bracket (optional but recommended)
   Remove the two bracket bolts securing the caliper bracket to the rear knuckle. This allows full inspection and cleaning of the bracket and rotor hat area.
   Torque spec

   Bracket Bolts102 Nm (75 lb-ft)
6. 6

   Remove piston from caliper body
   With the caliper off the vehicle and EPB in service mode, remove the piston. Place a wood block in the caliper bore and apply low-pressure compressed air through the fluid inlet to ease the piston out. If the piston resists, the EPB actuator may not be fully retracted — re-verify with the scan tool. Do not pry on the piston face.
   ⚠Keep fingers clear of the bore — pistons can eject suddenly under air pressure.
7. 7

   Remove dust boot and piston seal
   Carefully extract the dust boot from its groove. Using a non-metallic pick, remove the square-cut piston seal from the bore groove. Avoid scratching the bore — any damage to the bore sealing surface means the caliper body must be replaced.
8. 8

   Clean and inspect
   Clean the caliper bore, piston, and slide pins thoroughly with brake parts cleaner. Inspect the bore for pitting or scoring, the piston for corrosion or chrome flaking, and the slide pins for wear or seizure. Replace any component that is not visibly perfect. Inspect the EPB actuator shaft seal area for fluid contamination — contamination indicates internal seal failure and the caliper assembly must be replaced.
9. 9

   Reassemble caliper
   Lubricate the new piston seal with clean DOT 4 brake fluid and seat it in the bore groove. Install the new dust boot onto the piston, lubricate the piston with brake fluid, and press it squarely back into the bore until fully seated. Seat the dust boot lip into the caliper groove. Install new slide pin boots, apply silicone brake grease to the slide pins, and reinstall.

Reassembly

1. Reinstall the caliper bracket to the knuckle and torque the bracket bolts (refer to Bracket Bolts spec).
2. Install brake pads with anti-rattle clips properly seated in the bracket.
3. Position the rebuilt caliper over the pads and install the slide pin bolts; torque to the Caliper Slide Pin Bolts spec after applying silicone brake grease to the pin shafts.
4. Reconnect the hydraulic line using new crush washers if applicable; torque to Line Fittings spec with a line wrench.
5. Reconnect the EPB actuator harness and route securely.
6. Reinstall wheels; torque lug nuts in a star pattern to the Wheel Lug Nuts spec.
7. Reconnect the 12V battery.
8. Wake the vehicle and connect the diagnostic tool. Bleed both rear calipers (and ideally all four corners) using fresh DOT 4 fluid until clean, bubble-free fluid flows. Torque each Bleeder Screw to spec — do not overtighten.
9. Use the diagnostic tool to exit EPB service mode and command the actuators back to the home/applied position. Cycle the EPB on/off several times via the touchscreen and verify both rear actuators respond.

Verification

• With the vehicle awake, check the touchscreen for any brake system, ABS, or EPB warnings — there should be none.
• Confirm firm brake pedal after 3-4 pumps; pedal should not sink under sustained pressure.
• Inspect the caliper, hydraulic fitting, and bleeder for any fluid weep after pedal pressure is applied.
• Apply and release the EPB via the touchscreen; listen for both rear actuators cycling.
• Perform a low-speed roll test (5-10 mph) in a safe area, applying brakes gently to bed in pads and verify even braking with no pull.
• Perform progressively harder stops to bed pads per pad manufacturer's procedure.
• Note in service records: brake fluid was flushed — next Tesla-recommended brake fluid service is 2 years from this date regardless of mileage.
• Recheck lug nut torque after the first 50 miles.

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