Radiator Removal and Service

Complete removal and reinstallation of the radiator assembly on a 2005 Dodge Viper 8.3L V10, including coolant drain, fan shroud removal, and hose disconnection.

Warnings

Tools required

Parts

• Radiator (if replacing) × 1 — Use OEM specification
• Upper radiator hose (if damaged) × 1 — Use OEM specification
• Lower radiator hose (if damaged) × 1 — Use OEM specification
• Hose clamps (if reusing is not recommended) × 4 — Worm-gear style, various sizes
• Coolant recovery tank cap (inspect and replace if worn) × 1 — Use OEM specification

Fluids

• Zerex G-05 HOAT 50/50 coolant — 19 qt

Preparation

1. Ensure the engine is completely cold to the touch before beginning work.
2. Park the vehicle on level ground and engage the parking brake.
3. Disconnect the negative battery cable to prevent electrical issues during the procedure.
4. Place a large drain pan beneath the radiator drain petcock, positioned to catch coolant from both the drain and lower hose.
5. Remove the engine cover if equipped by lifting upward on the front tabs and pulling forward.

Procedure

1. 1

   Drain the Cooling System
   Open the radiator drain petcock located at the driver's side lower corner of the radiator. Turn counterclockwise by hand to open. Allow coolant to drain completely into the drain pan. Once drained, close the petcock hand-tight only. Remove the coolant recovery tank cap to allow the system to vent and drain more completely.
   Torque spec

   Drain Petcock5 Nm (4 lb-ft)
2. 2

   Remove the Upper Radiator Hose
   Locate the upper radiator hose connection at the top driver's side of the radiator. Use hose clamp pliers to compress and slide the spring clamp back approximately 2 inches from the radiator neck. Twist the hose to break the seal, then pull it straight off the radiator fitting. Be prepared for residual coolant spillage.
3. 3

   Remove the Lower Radiator Hose
   Access the lower radiator hose connection at the bottom driver's side of the radiator. Compress and slide the spring clamp back from the radiator neck using hose clamp pliers. Twist and pull the hose off the fitting. Additional coolant will drain from this connection.
4. 4

   Disconnect the Coolant Recovery Tank Hose
   Locate the small overflow hose connected to the radiator neck (typically at the top passenger side). Slide the clamp back and remove the hose from the radiator fitting. Position the hose end upward or cap it to prevent spillage.
5. 5

   Disconnect the Transmission Cooler Lines
   The 2005 Dodge Viper is equipped exclusively with a 6-speed manual transmission (Tremec T56) and therefore has NO automatic transmission cooler lines connected to the radiator. Skip this step entirely for all 2005 Vipers. Place a drain pan beneath the connections. Use a flare-nut wrench to loosen the fittings, turning counterclockwise. Remove both lines and cap or plug the openings immediately to prevent fluid loss and contamination. Expect approximately 1 cup of ATF to drain from the lines.
6. 6

   Remove the Upper Fan Shroud
   Locate the upper fan shroud bolts securing the shroud to the radiator. Remove 4 bolts securing the upper portion of the fan shroud to the radiator support using a 10mm socket. Lift the upper shroud section upward and away from the fan blades, then remove it from the engine bay. Note: the 2005 Viper uses electric cooling fans mounted to the shroud rather than a mechanical water-pump-driven fan; disconnect the electric fan wiring connectors before removing the fan/shroud assembly. Note: The electric cooling fan blades have sharp edges. Keep hands clear and ensure the fan wiring is disconnected before handling the fan/shroud module.
   ⚠The mechanical fan blades have sharp edges. Keep hands clear when maneuvering the shroud around the fan assembly.
   Torque spec

   Fan Shroud Bolts10 Nm (7 lb-ft)
7. 7

   Remove the Lower Fan Shroud
   Remove 2 bolts at the bottom of the lower fan shroud securing it to the radiator support using a 10mm socket. Carefully lift the lower shroud upward and over the fan blades, then remove it from the engine bay.
   Torque spec

   Fan Shroud Bolts10 Nm (7 lb-ft)
8. 8

   Remove the Radiator Mounting Bolts
   Locate the radiator mounting brackets at the top corners of the radiator. Remove 2 bolts securing the radiator to the core support, one on each side, using a 10mm socket. The radiator is now free to be lifted out. Note the position of any rubber isolation mounts or spacers on the lower mounting points.
9. 9

   Remove the Radiator Assembly
   Carefully lift the radiator straight upward and out of the engine bay. Tilt the top toward you slightly as you lift to clear the fan blades and other obstructions. Be aware that residual coolant will drain from the radiator core as you lift it. Once clear, set the radiator on a clean work surface with the core facing upward.
10. 10

    Inspect and Service
    Inspect the radiator for damage, leaks, bent fins, or corrosion. Inspect the radiator end tanks and neck fittings for cracks or damage. Inspect all rubber hoses for cracks, softness, or swelling and replace as needed. Inspect the rubber lower mounting isolators on the radiator support for deterioration. Clean any debris from the radiator core fins using compressed air blown from the engine side outward. If installing a new radiator, transfer the drain petcock if not pre-installed.
11. 11

    Install the Radiator Assembly
    Carefully lower the radiator into the engine bay, guiding the lower mounting tabs into the rubber isolators on the radiator support. Ensure the radiator is seated fully into both lower mounts before proceeding. Align the upper mounting brackets with the holes in the core support.
12. 12

    Install the Radiator Mounting Bolts
    Install the 2 upper radiator mounting bolts, one at each upper corner. Torque to specification using a torque wrench. Do not overtighten as the mounting brackets are designed to allow thermal expansion.
13. 13

    Install the Lower Fan Shroud
    Position the lower fan shroud over the fan blades and into place against the radiator. Install the 2 lower mounting bolts and torque to specification.
    Torque spec

    Fan Shroud Bolts10 Nm (7 lb-ft)
14. 14

    Install the Upper Fan Shroud
    Position the upper fan shroud over the fan blades and align it with the radiator mounting points. Install the 4 upper shroud bolts and torque to specification. Verify the shroud does not contact the fan blades at any point.
    Torque spec

    Fan Shroud Bolts10 Nm (7 lb-ft)
15. 15

    Reconnect the Transmission Cooler Lines
    The 2005 Dodge Viper is manual-transmission only and has no transmission cooler lines; this step does not apply and should be omitted.
    ℹ️Manual transmission Vipers do not have transmission cooler lines. Skip this step if not equipped.
    Torque spec

    Transmission Cooler Lines25 Nm (18 lb-ft)
16. 16

    Reconnect the Coolant Recovery Tank Hose
    Push the overflow hose onto the radiator neck fitting until fully seated. Slide the clamp into position over the connection point.
17. 17

    Install the Lower Radiator Hose
    Push the lower radiator hose onto the radiator fitting until fully seated against the stop. Slide the spring clamp forward into position over the hose and fitting. Ensure the clamp is positioned correctly in the bead area of the fitting.
18. 18

    Install the Upper Radiator Hose
    Push the upper radiator hose onto the radiator fitting until fully seated. Slide the spring clamp forward into position over the hose and fitting. Verify the connection is secure.
19. 19

    Refill the Cooling System
    Close the radiator drain petcock hand-tight. Using a funnel, slowly pour Zerex G-05 HOAT 50/50 coolant into the designated system fill/pressure bottle per the factory fill and bleed procedure until full. Pour coolant into the recovery tank to the COLD FULL mark. Reinstall the radiator cap. Reconnect the negative battery cable. Start the engine and allow it to warm to operating temperature with the heater on high. Monitor for leaks at all connections. As the thermostat opens, the coolant level will drop; shut off the engine and add coolant as needed. Once the engine reaches operating temperature and the cooling fans cycle, shut off the engine and allow it to cool. Recheck the coolant level in both the radiator and recovery tank, topping off as necessary.
    ⚠The cooling system must be properly burped of air. Failure to bleed air from the system can result in overheating and engine damage.

Reassembly

1. Reinstall the engine cover if equipped by aligning the rear tabs first, then pressing down on the front clips until they lock.
2. Verify all hose clamps are positioned correctly and all connections are secure before operating the vehicle.
3. Check the transmission fluid level if cooler lines were disconnected and top off with ATF+4 if necessary.

Verification

• Start the engine and visually inspect all coolant hose connections and the radiator drain petcock for leaks.
• Allow the engine to reach operating temperature and verify the cooling fans engage properly.
• Check the coolant level in the recovery tank after the engine cools and top off to the COLD FULL mark if needed.
• Test drive the vehicle and monitor the temperature gauge to ensure normal operating temperature is maintained.
• Recheck all connections and fluid levels after the first drive cycle.

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