This procedure drains and replaces the EV battery and motor coolant system on the 2022 Rivian EDV 500, ensuring proper thermal management of the electric drivetrain components.

Warnings

Tools required

Parts

• Coolant drain plug seal/O-ring × 1 — Use OEM specification
• Coolant reservoir cap seal (if damaged) × 1 — Use OEM specification

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Power down vehicle completely and remove key fob from cabin area
3. Allow coolant system to cool for minimum 2 hours if vehicle was recently operated
4. Raise vehicle on lift or support securely on jack stands rated for electric vehicle weight
5. Remove underbody panels to access coolant system drain points (front and rear sections)
6. Connect Rivian diagnostic scan tool and verify no active HV system faults
7. Use scan tool to disable high voltage system and confirm isolation status

Procedure

1. 1

   Access coolant reservoir and verify system pressure
   Locate the coolant reservoir in the front compartment. Carefully place a shop towel over the reservoir cap and slowly loosen to release any residual pressure. Listen for hissing and wait until all pressure is released before fully removing cap. Inspect coolant level and condition.
2. 2

   Drain battery thermal management circuit
   Locate the battery coolant drain valve on the underside of the battery pack (driver side, mid-pack location). Position drain pan underneath. Using appropriate socket, carefully open the drain valve. Allow coolant to drain completely, which may take 15-20 minutes due to the extensive routing through the battery pack.
3. 3

   Drain motor coolant circuits
   Locate drain points for front and rear motor cooling circuits. Front motor drain is below the front drive unit; rear motor drain is below the rear drive unit. Open both drain valves and allow complete drainage. These circuits are smaller and should drain in 5-10 minutes each.
4. 4

   Drain coolant reservoir
   Remove the lower coolant hose from the reservoir to drain remaining coolant. Use a fluid transfer pump if needed to remove coolant that won't drain by gravity. Inspect reservoir for debris or contamination.
5. 5

   Inspect drain plugs and replace seals
   Examine all drain plug O-rings and sealing washers for damage, cracking, or deformation. Replace any compromised seals with OEM parts. Clean drain plug threads and sealing surfaces thoroughly.
6. 6

   Close all drain points
   Install drain plugs with new seals at all drain locations. Hand-tighten first to ensure proper thread engagement, then tighten securely. Without torque specifications, use professional judgment to achieve proper seal without overtightening aluminum components.
7. 7

   Reconnect reservoir hose
   Reattach the lower coolant hose to the reservoir. Ensure hose clamp is properly seated and tightened. Verify all coolant system connections that were disturbed are secure.
8. 8

   Perform vacuum fill procedure
   Connect coolant vacuum fill tool to the reservoir. Follow tool manufacturer instructions to create vacuum in the cooling system (typically 20-25 inches Hg). Maintain vacuum for 5 minutes to check for leaks. If vacuum holds, proceed with fill. Submerge fill tool hose in fresh EV coolant and allow vacuum to draw coolant into system.
9. 9

   Fill coolant system to specification
   Continue vacuum fill process until system accepts approximately 10 quarts of EV Battery/Motor Coolant. Fill reservoir to the MAX cold fill line. Disconnect vacuum tool and install reservoir cap.
10. 10

    Initialize coolant circulation
    Using the Rivian diagnostic scan tool, activate the coolant pump circulation function. Run pumps in service mode to circulate coolant through all circuits and purge air. Monitor for leaks at all drain points and connections.
11. 11

    Bleed air from system
    With pumps running, check coolant level in reservoir and top off as needed. Continue circulation for 10-15 minutes, periodically checking and adding coolant as air purges from system. System is fully bled when coolant level stabilizes and no bubbles are visible in reservoir.
12. 12

    Perform system pressure test
    Using scan tool, command coolant system to operating pressure. Inspect all drain points, hose connections, and fittings for leaks. Allow system to hold pressure for 5 minutes and verify no pressure loss or visible leaks.
13. 13

    Reinstall underbody panels
    Clean and reinstall all underbody protection panels that were removed. Ensure all fasteners are properly secured and panels are correctly aligned.

Reassembly

1. Verify all underbody panels are properly secured with all fasteners installed
2. Double-check that coolant reservoir cap is securely installed
3. Remove vehicle from lift and lower to ground
4. Top off coolant reservoir to proper cold fill level if needed after system has settled

Verification

• Use diagnostic scan tool to clear any service mode flags and re-enable high voltage system
• Power on vehicle and verify no coolant system warning lights or messages appear on instrument cluster
• Check coolant level in reservoir with vehicle at operating temperature - should be between MIN and MAX hot fill lines
• Perform a test drive of at least 15 minutes to bring thermal management system to full operating temperature
• After test drive, recheck coolant level when system has cooled and top off if necessary
• Inspect under vehicle for any signs of coolant leaks at drain points and connections
• Use scan tool to verify coolant temperature sensors are reading properly and system is functioning normally
• Document service in vehicle maintenance records with date and coolant quantity used

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