Parking Brake Actuator

Replace the electronic parking brake actuator on the 2025 Rivian EDV 500, restoring proper parking brake function.

Warnings

Tools required

Parts

• Parking brake actuator assembly × 1 — Use OEM Rivian specification
• Actuator mounting hardware kit × 1 — Use OEM specification if corroded
• Brake caliper mounting bolts × 2 — Replace if thread damage occurs

Fluids

• DOT 4 Brake Fluid — 0.5 qt

Preparation

1. Park vehicle on level, solid surface and place wheel chocks in front of front wheels
2. Verify vehicle is in Park mode and power is OFF
3. Wear insulated gloves rated for 600V DC throughout procedure
4. Disconnect 12V auxiliary battery using service disconnect procedure (located in front trunk area)
5. Wait minimum 5 minutes for capacitor discharge before proceeding
6. Raise rear of vehicle using designated lift points per Rivian service manual and support with rated jack stands
7. Remove rear wheel on side requiring actuator replacement
8. Connect diagnostic tool to OBD-II port and power on to access service functions

Procedure

1. 1

   Place parking brake in service mode
   Using diagnostic tool, navigate to Brake System menu and select Parking Brake Service Mode. This will retract the parking brake actuator pistons to their service position. Confirm successful retraction on diagnostic display before proceeding. If service mode cannot be activated, check for fault codes and resolve before continuing.
2. 2

   Remove brake caliper
   Remove the two brake caliper mounting bolts securing the rear caliper to the bracket. Support the caliper with a bungee cord or wire hook to the suspension, ensuring no stress is placed on the brake hose. Do not allow caliper to hang by the brake hose.
3. 3

   Disconnect parking brake electrical connector
   Locate the electrical connector on the parking brake actuator mounted to the rear brake caliper. Press the connector lock tab and carefully pull the connector straight out from the actuator. Inspect connector pins for corrosion or damage. Clean if necessary with electrical contact cleaner.
4. 4

   Disconnect brake hydraulic line
   Place a drain pan beneath the caliper. Using appropriate wrench, carefully loosen the brake line fitting at the caliper/actuator junction. Brake fluid will drain - capture it properly. Immediately cap or plug the brake line to prevent additional fluid loss and contamination entry.
   ⚠DOT 4 brake fluid is corrosive to paint and harmful if ingested. Use caution during removal and disposal.
5. 5

   Remove parking brake actuator from caliper
   Locate the fasteners securing the parking brake actuator to the brake caliper body (typically 2-4 Torx bolts). Remove these fasteners and carefully separate the actuator from the caliper. Note the orientation and position of any alignment pins or gaskets for reinstallation.
6. 6

   Inspect mounting surfaces
   Thoroughly inspect the caliper mounting surface for corrosion, damage, or wear. Clean mounting surfaces with wire brush and brake cleaner. Check that the actuator piston mechanism area in the caliper is free of debris. Inspect brake pads for unusual wear patterns that might indicate previous actuator malfunction.
7. 7

   Install new parking brake actuator
   Position new actuator onto caliper body, ensuring proper alignment of pins and mounting holes. Install new mounting hardware (or cleaned original hardware if in good condition) and tighten fasteners in a cross-pattern to ensure even seating. Verify actuator sits flush against caliper mounting surface with no gaps.
8. 8

   Reconnect brake hydraulic line
   Remove cap or plug from brake line. Thread brake line fitting into new actuator/caliper assembly by hand first to prevent cross-threading. Once hand-tight, use wrench to snug fitting securely. Do not over-tighten as this can damage the fitting or actuator housing.
9. 9

   Reconnect electrical connector
   Align electrical connector with actuator pins and press firmly until lock tab clicks into place. Gently tug on connector to verify secure connection. Ensure wiring is routed properly and will not contact rotating components or hot surfaces.
10. 10

    Reinstall brake caliper
    Position brake caliper back onto mounting bracket, ensuring brake pads are properly aligned with rotor. Install caliper mounting bolts and tighten securely. Verify caliper moves freely on slide pins if applicable to this design.
11. 11

    Bleed brake system
    Using diagnostic tool or manual bleeding procedure, bleed the rear brake circuit to remove all air introduced during actuator replacement. Begin with the wheel furthest from master cylinder if bleeding entire system. Continue bleeding until clear fluid with no air bubbles flows from bleeder valve. Maintain proper brake fluid level in reservoir throughout bleeding process.
    ⚠️Air in brake lines will result in brake failure. Ensure thorough bleeding with firm pedal feel before operating vehicle.
12. 12

    Calibrate parking brake actuator
    Using diagnostic tool, navigate to Parking Brake Calibration function. Follow on-screen prompts to perform actuator initialization and calibration. This process teaches the system the new actuator's position parameters. Calibration typically takes 30-60 seconds and will involve audible motor operation. Verify successful calibration completion on diagnostic display.
13. 13

    Reinstall wheel and lower vehicle
    Reinstall rear wheel and tighten lug nuts in star pattern to proper specification. Lower vehicle from jack stands and perform final lug nut torque with vehicle on ground. Remove wheel chocks.
14. 14

    Reconnect 12V battery and test
    Reconnect 12V auxiliary battery. Power on vehicle and check for any brake system warning lights or fault codes. Test parking brake operation by engaging and disengaging multiple times while monitoring for unusual sounds or diagnostic alerts.

Reassembly

1. Ensure all electrical connectors are fully seated with locking tabs engaged
2. Verify brake hydraulic connections are secure with no leaks visible
3. Check brake fluid reservoir level and top off with DOT 4 fluid as needed
4. Torque wheel lug nuts to manufacturer specification (typically 150 ft-lbs for Rivian EDV)
5. Clear any stored fault codes from brake system after successful calibration

Verification

• With vehicle powered on, engage parking brake using switch - verify indicator illuminates and holding force is present
• Attempt to move vehicle with parking brake engaged - vehicle should not roll
• Disengage parking brake and verify indicator light extinguishes
• Test drive vehicle in safe area at low speed, verifying normal brake pedal feel and no warning lights
• Perform brake pedal feel test - pedal should be firm with no excessive travel or sponginess
• On slight incline, verify parking brake holds vehicle without rolling
• Use diagnostic tool to verify no active or pending brake system fault codes
• Check for brake fluid leaks around actuator and hydraulic connections after test drive

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