Coolant Reservoir

Remove and replace the coolant reservoir tank on a 2008 Dodge Viper 8.4L V10, including coolant drain and refill procedures.

Warnings

Tools required

Parts

• Coolant reservoir tank × 1 — Use OEM specification
• Coolant reservoir cap (if damaged) × 1 — Use OEM specification

Fluids

• Mopar HOAT coolant 50/50 — 2 qt

Preparation

1. Ensure engine is completely cold to the touch
2. Park vehicle on level ground and engage parking brake
3. Open hood and prop securely
4. Place drain pan beneath the passenger side of the engine bay

Procedure

1. 1

   Relieve cooling system pressure
   Slowly turn the coolant system pressure cap counterclockwise to release any residual pressure. On the Viper, verify whether the pressurized cap is on the reservoir/degas bottle before opening. Wait for any hissing to stop, then remove the cap completely. Set the cap aside in a clean location.
2. 2

   Drain coolant from reservoir
   The reservoir has a drain hose at the bottom. Locate the hose clamp securing the lower drain hose to the reservoir outlet. Using pliers, squeeze and slide the clamp down the hose away from the reservoir fitting. Pull the hose off the reservoir outlet fitting and direct it into the drain pan to empty the reservoir contents.
3. 3

   Disconnect upper coolant hose
   Locate the upper hose connection on the reservoir (connects to the radiator overflow). Using pliers, reposition the hose clamp by squeezing and sliding it down the hose approximately 2 inches. Twist and pull the hose off the reservoir fitting. Be prepared for residual coolant spillage.
4. 4

   Remove reservoir mounting fasteners
   The reservoir is secured to the mounting structure with fasteners at the mounting bracket (verify exact count and type against factory service documentation). Remove the fasteners completely and retain them for reinstallation.
5. 5

   Extract reservoir from engine bay
   Lift the reservoir upward and tilt as needed to navigate around nearby engine components. The reservoir may require slight rotation to clear the firewall area. Remove the reservoir from the vehicle and inspect the mounting bracket for damage.
6. 6

   Prepare new reservoir
   Inspect the new reservoir for shipping damage or defects. Transfer the mounting bracket from the old reservoir to the new unit if not pre-installed. Verify that all fittings are clean and free of debris.
7. 7

   Install new reservoir
   Position the new reservoir into the mounting location, orienting the fittings toward their respective hose connections. Align the mounting bracket holes with the inner fender attachment points. Install the reservoir mounting fasteners and tighten to the factory-specified torque (verify count, type, and torque against factory service documentation).
8. 8

   Reconnect coolant hoses
   Push the upper hose onto the reservoir fitting until it seats completely against the fitting shoulder. Slide the hose clamp back into position over the hose-to-fitting junction and squeeze to secure. Repeat the process for the lower drain hose, ensuring the clamp is positioned 0.5 inches from the fitting end.
9. 9

   Refill cooling system
   Using a funnel, pour Mopar HOAT 50/50 coolant into the reservoir until the level reaches the cold fill/MAX line marked on the reservoir body (verify correct fill line against factory documentation). Do not overfill. Install the reservoir cap and turn clockwise until it clicks into the locked position.
10. 10

    Bleed air from cooling system
    Start the engine and allow it to idle with the heater set to maximum temperature. Monitor the coolant level in the reservoir. As the engine warms and the thermostat opens, air pockets will be purged and the coolant level may drop. Add additional coolant as needed to maintain the COLD FILL level. Run the engine until the cooling fans cycle on, then shut off and allow to cool.
11. 11

    Verify final coolant level
    Once the engine has cooled completely, check the reservoir coolant level again. The level should be at the COLD FILL line. Top off if necessary and reinstall the cap. Inspect all hose connections for leaks.

Reassembly

1. Ensure both hose clamps are properly positioned and secure
2. Verify reservoir cap is fully seated and locked
3. Wipe down any coolant residue from engine bay surfaces

Verification

• With engine cold, confirm coolant level is at COLD FILL line on reservoir
• Start engine and check for leaks at both hose connections and reservoir mounting area
• Allow engine to reach operating temperature and verify cooling fans cycle properly
• Check for leaks again after engine reaches full operating temperature
• After test drive, recheck coolant level when engine is cold and top off if needed

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