Parking Brake Actuator

Replacement of the rear parking brake actuator (electric park brake motor) on a 2024 Model X. The EPB motor is integrated into the rear caliper assembly and requires placing the system into service/transport mode before mechanical disassembly.

Warnings

Tools required

Parts

• Rear parking brake actuator (EPB motor) — manufacturer-specified for 2024 Model X × 1 — Refer to Tesla EPC for current rear caliper EPB motor part number
• Actuator-to-caliper O-ring/seal (if supplied separately) × 1 — OEM seal kit for EPB motor

Fluids

• DOT 3 Brake Fluid (top-up only if system was opened) — 0.25 qt

Preparation

1. Park on level ground, place in P, engage parking brake.
2. Exit ALL doors with 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 located in the frunk (similar position to Model S). Follow the access panel removal procedure and isolate the negative terminal first.
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 12V: enable 'Jack Mode' via the touchscreen (Controls > Service > Jack Mode) to disable air suspension self-leveling.
7. Using a compatible diagnostic tool, command the EPB into Service/Open (transport) mode so the actuator retracts fully. This MUST be done before 12V disconnect or mechanical removal.
8. Loosen rear lug nuts while the wheels are still on the ground.
9. Lift the vehicle using only Tesla-approved jack pad locations and support on jack stands rated for the curb weight. Remove the rear wheel(s) on the affected side(s).

Procedure

1. 1

   Confirm EPB is in service mode
   Verify via the diagnostic tool that the EPB motor has retracted to its service position. If the actuator did not retract (e.g., due to a failed motor), document this — manual release of the caliper piston may be required during disassembly. Do not force a seized actuator.
   ⚠If the actuator is electrically dead and cannot be retracted, plan for additional disassembly time; the caliper may need to be removed with the actuator still pressurized.
2. 2

   Disconnect EPB actuator electrical connector
   Locate the EPB actuator on the inboard face of the rear caliper. Release the connector lock tab and disconnect the harness. Inspect the connector for corrosion or water intrusion — a known cause of EPB faults. Free the harness from any retaining clips on the caliper or trailing arm.
3. 3

   Decision point — actuator-only vs. caliper removal
   On the 2024 Model X rear caliper, the EPB actuator is bolted to the rear of the caliper body and can typically be replaced without removing the caliper or opening the hydraulic circuit. If the new actuator is supplied as a bolt-on motor with seal, proceed to Step 4. If service requires caliper removal, proceed to Step 6.
4. 4

   Remove the parking brake actuator (in-place method)
   Remove the actuator mounting fasteners securing the EPB motor to the rear of the caliper. Support the actuator as the last fastener is removed. Withdraw the actuator straight back from the caliper to avoid damaging the drive coupling and seal. Inspect the caliper bore and seal surface for debris or fluid; clean as needed with brake cleaner — do not allow solvent into the caliper piston cavity.
5. 5

   Install the new actuator
   Transfer or install the new seal/O-ring per the kit instructions. Align the actuator drive with the caliper spindle (rotate gently by hand to engage). Seat the actuator flush against the caliper without forcing. Install the mounting bolts and torque evenly in a cross pattern.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
6. 6

   (If required) Remove caliper for access
   If full caliper removal is necessary: remove the two caliper guide/slide pin bolts and lift the caliper off the rotor. Support the caliper with a hanger — never let it hang by the flexible brake hose. If the hydraulic line must be disconnected, plug the line immediately and plan to bleed the system. Then perform actuator R&R per Steps 4–5.
   ⚠Do not depress the brake pedal while the caliper is removed.
7. 7

   (If caliper was removed) Reinstall caliper
   Apply silicone brake grease to the slide pins. Reinstall the caliper onto the bracket and torque the slide pin bolts. If the caliper bracket was removed from the knuckle, torque the bracket bolts to spec with threadlocker as specified.
   Torque spec

   Caliper Slide Pin Bolts35 Nm (26 lb-ft)

   Caliper Bolts88 Nm (65 lb-ft)
8. 8

   Reconnect EPB harness
   Route the harness back through its original retention clips, ensuring no contact with the rotor, suspension, or heat shields. Seat the connector fully until the lock clicks. Verify strain relief.
9. 9

   (If hydraulic line was opened) Bleed the brake system
   Top off the master cylinder reservoir with fresh DOT 3 brake fluid. Bleed the affected caliper at the bleeder screw using a two-person pedal method or pressure bleeder. Monitor reservoir level continuously to prevent introducing air. Tighten the bleeder to spec — do not overtighten as the fitting is easily damaged.
   Torque spec

   Bleeder Screw10 Nm (7 lb-ft)
10. 10

    Reinstall wheel
    Mount the wheel and run lug nuts down by hand. Lower the vehicle until the tire just contacts the ground, then torque lug nuts in a star pattern to spec. Re-torque after the vehicle is fully on the ground.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Lower the vehicle fully off the jack stands.
2. Reconnect the 12V low-voltage battery in the frunk (positive first, then negative); ensure terminals are clean and torqued to OEM specification — refer to Tesla Service Manual.
3. Reinstall the frunk 12V access cover.
4. Power on the vehicle. Allow the BMS and chassis controllers to wake fully (1–2 minutes).
5. Exit Jack Mode via the touchscreen and allow air suspension to re-level.
6. Using the diagnostic tool, command the EPB out of service mode and run the calibration/bedding-in routine for the new actuator.

Verification

• Confirm no EPB-related alerts appear on the touchscreen ('Parking Brake Needs Service', 'Apply Brake Pedal', etc.).
• With the vehicle stationary on level ground, cycle the parking brake apply/release several times via the touchscreen or shifter and listen for normal motor operation on both rear corners.
• Verify the parking brake holds the vehicle on a moderate grade with the drive selector in N.
• Perform a low-speed brake test (5–10 mph in an empty area) to confirm normal hydraulic brake function and no pedal sponginess (especially if the system was bled).
• Re-check lug nut torque after approximately 50 miles of driving.
• Note: Tesla recommends brake fluid replacement every 2 years regardless of mileage — log the date if fluid was topped up or bled during this service.

Related trouble codes on this vehicle

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