Coolant Outlet

This procedure covers the removal and replacement of the coolant outlet on the 2025 Rivian EDV 500 dual motor AWD electric vehicle, which routes coolant for the battery and motor thermal management system.

Warnings

Tools required

Parts

• Coolant outlet assembly × 1 — Use OEM specification
• Coolant outlet gasket or O-ring × 1 — Use OEM specification
• Hose clamps (if damaged) × 2 — Use OEM specification
• Coolant temperature sensor (if integrated) × 1 — Use OEM specification

Fluids

• EV Battery/Motor Coolant — 3 qt

Preparation

1. Park vehicle on level ground and engage parking brake
2. Ensure the vehicle has been off for at least 2 hours and the cooling system is completely cool to the touch
3. Open the front hood and secure in the open position
4. Disconnect the 12V auxiliary battery negative terminal and wait 2 minutes for system capacitors to discharge
5. Follow manufacturer lockout/tagout procedures for high voltage system isolation if accessing components near HV wiring
6. Remove any underbody panels or access covers required to reach the coolant outlet location
7. Place coolant drain pan beneath the work area
8. Document or photograph coolant hose routing and electrical connector positions for reference during reassembly

Procedure

1. 1

   Drain coolant from system
   Locate the coolant drain valve or lowest coolant hose connection point accessible near the coolant outlet. Open the drain valve or carefully loosen the hose clamp and disconnect the lower coolant hose to drain coolant into the collection pan. Allow system to drain completely until flow stops. If the outlet is on the motor cooling circuit, you may only need to drain that specific circuit rather than the entire system.
2. 2

   Disconnect electrical connectors
   Locate any electrical connectors attached to the coolant outlet assembly, such as coolant temperature sensors or level sensors. Press the connector lock tabs and carefully pull connectors straight off. If connectors are corroded or stuck, use a small flathead screwdriver to gently release the locking tabs. Secure connectors away from the work area to prevent damage.
3. 3

   Remove inlet coolant hose
   Using hose clamp pliers, compress or loosen the clamp securing the inlet coolant hose to the outlet assembly. Slide the clamp back along the hose away from the connection point. Twist the hose gently while pulling to break any seal and remove from the outlet nipple. Be prepared for residual coolant to drain. Inspect the hose end for damage or cracking.
4. 4

   Remove outlet coolant hose
   Repeat the process for the outlet coolant hose connection. Compress or loosen the hose clamp, slide it back along the hose, and twist while pulling to remove the hose from the outlet assembly. Ensure both hoses are positioned away from the work area and elevated if possible to prevent further coolant drainage.
5. 5

   Remove coolant outlet mounting fasteners
   Locate and remove all bolts or fasteners securing the coolant outlet to the motor housing or coolant manifold. These are typically 8mm, 10mm, or 12mm head bolts. Support the outlet assembly with one hand while removing the final fastener to prevent it from dropping. There may be 2-4 mounting bolts depending on the specific outlet design.
6. 6

   Remove coolant outlet assembly
   Carefully pull the coolant outlet assembly away from the mounting surface. If it resists, gently twist while pulling to break the gasket seal. Do not pry against aluminum housings as this can cause damage. Once free, inspect the mounting surface on the motor or manifold for damage, corrosion, or debris.
7. 7

   Clean mounting surfaces
   Thoroughly clean the mounting surface on the motor housing or coolant manifold using a clean rag or plastic scraper. Remove all traces of old gasket material, coolant residue, and debris. The surface must be completely clean and smooth for the new gasket to seal properly. Inspect for any cracks, corrosion, or damage that could prevent proper sealing.
8. 8

   Prepare new coolant outlet
   Unbox the new coolant outlet assembly and verify it matches the original part configuration. Install the new gasket or O-ring onto the outlet assembly in the proper groove. If the temperature sensor is a separate component, transfer it from the old outlet or install a new sensor with appropriate thread sealant or O-ring as specified by the manufacturer.
9. 9

   Install new coolant outlet
   Position the new coolant outlet assembly with gasket onto the mounting surface, ensuring proper alignment with the bolt holes and coolant passages. Start all mounting bolts by hand to ensure proper thread engagement. Tighten bolts in a cross-pattern sequence to ensure even gasket compression. Since no torque specification is provided in the database, tighten snugly to approximately 10-15 ft-lbs for typical aluminum housing applications, being careful not to over-torque and strip threads.
10. 10

    Reconnect coolant hoses
    Push the outlet coolant hose firmly onto the outlet nipple until it is fully seated against the stop. Position the hose clamp over the connection area and tighten securely. Repeat for the inlet hose connection. Ensure both hoses are routed properly without kinks or tension that could cause stress on the connections. Replace any damaged or corroded hose clamps with new units.
11. 11

    Reconnect electrical connectors
    Push electrical connectors firmly onto their respective sensors or switches until they click into place. Verify the locking tabs are fully engaged. Gently tug on each connector to confirm it is secure. Ensure no wires are pinched or routed where they could contact hot or moving components.
12. 12

    Refill cooling system
    Using a funnel, add the specified EV Battery/Motor Coolant to the cooling system fill point. Fill slowly to allow air to escape. Add approximately 3 quarts or until the system reaches the proper level. Consult the vehicle service information for the specific fill procedure, as EV cooling systems often require special bleeding procedures to remove air pockets from multiple circuits.
13. 13

    Bleed cooling system
    Follow the manufacturer-specified bleeding procedure for the Rivian EDV cooling system. This typically involves running the coolant pump(s) through service mode activation using the vehicle diagnostic system or by cycling the vehicle through specific operational modes. Open any bleeder valves in sequence as specified. Continue bleeding until no air bubbles are visible in the coolant and the system maintains proper level.
14. 14

    Pressure test system
    If available, use a cooling system pressure tester to pressurize the system to the specified test pressure (typically 15-20 psi for EV systems). Monitor for 5 minutes to verify no leaks are present at the new coolant outlet or hose connections. If pressure drops, locate and repair the leak before proceeding.

Reassembly

1. Reinstall any underbody panels or access covers that were removed
2. Reconnect the 12V auxiliary battery negative terminal
3. Verify all tools and parts have been removed from the engine compartment
4. Double-check all hose clamps are tight and electrical connectors are fully engaged
5. Ensure the coolant reservoir is filled to the proper level marking

Verification

• Start the vehicle and allow the thermal management system to activate (may require driving or using service mode to activate pumps)
• Monitor coolant temperature using the vehicle display or scan tool to verify proper system operation
• Check for any coolant leaks around the new outlet assembly, hose connections, and ground beneath the vehicle
• Verify coolant level remains stable after system reaches operating temperature and fans cycle
• Check for any warning lights or fault codes related to the cooling system
• Take a short test drive and recheck coolant level and inspect for leaks after the system has cycled through normal operating conditions
• Verify coolant temperature sensor readings are within normal range if monitoring with scan tool

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