Radiator

Complete removal and replacement of the radiator on a 2008 Dodge Viper 8.4L V10, including coolant drain, hose disconnection, fan assembly removal, and radiator extraction.

Warnings

Tools required

Parts

• Radiator assembly × 1 — Use OEM specification
• Radiator cap (if damaged) × 1 — Use OEM specification
• Lower radiator hose (if cracked) × 1 — Use OEM specification
• Upper radiator hose (if cracked) × 1 — Use OEM specification

Fluids

• Mopar HOAT coolant 50/50 — 19 qt

Preparation

1. Verify engine is completely cool to the touch (minimum 2 hours after last operation)
2. Position vehicle on level ground and engage parking brake
3. Place drain pan beneath radiator drain location on passenger side of vehicle
4. Remove radiator cap slowly to release any residual pressure
5. Disconnect negative battery terminal to prevent fan motor activation during service

Procedure

1. 1

   Drain cooling system
   Locate the radiator drain petcock at the lower corner of the radiator (verify presence and side against factory documentation; if no petcock is fitted, drain via the lower radiator hose). Open the petcock by turning counterclockwise and allow coolant to drain completely into the collection pan. If the petcock is seized or damaged, remove the lower radiator hose instead. Once drained, inspect the drained coolant for contamination or discoloration indicating internal engine issues.
2. 2

   Remove upper radiator hose
   Locate the upper radiator hose connecting the radiator to the thermostat housing on the engine. Use hose clamp pliers or a flat blade screwdriver to loosen the hose clamp at the radiator end. Slide the clamp back along the hose, then twist and pull the hose off the radiator neck. Be prepared for residual coolant spillage. Repeat for the engine side if needed for clearance.
3. 3

   Remove lower radiator hose
   Access the lower radiator hose connection at the bottom of the radiator on the driver side. Loosen the hose clamp and slide it back along the hose. Twist and pull the hose off the radiator outlet. Inspect both upper and lower hoses for cracks, softness, or deterioration and replace if necessary.
4. 4

   Disconnect transmission cooler lines
   The 2008 Dodge Viper is equipped exclusively with a Tremec T56 6-speed manual transmission and has no transmission cooler lines connected to the radiator. Skip this step entirely; no transmission cooler line service is required. Place a drain pan beneath the connections. Use a line wrench to loosen the fittings at the radiator. Expect transmission fluid spillage. Cap or plug the lines and radiator ports to prevent contamination.
5. 5

   Disconnect cooling fan electrical connectors
   Locate the electrical connectors for the cooling fan motors on the fan shroud assembly. Press the connector locking tabs and disconnect both fan motor connectors. Note the routing of the wiring harness for reinstallation.
6. 6

   Remove cooling fan assembly
   Remove the 4 bolts securing the cooling fan shroud assembly to the radiator. These are typically located at the corners of the fan shroud. Carefully lift the fan shroud and fan assembly straight up and out of the engine bay. The assembly is bulky but not excessively heavy. Set aside in a safe location.
7. 7

   Disconnect overflow hose
   Locate the coolant overflow hose connected to the radiator neck (typically on the driver side near the cap). Loosen the hose clamp and slide it back, then pull the overflow hose off the radiator fitting.
8. 8

   Remove radiator mounting hardware
   Locate the radiator mounting brackets at the top of the radiator. Remove the 2 bolts securing the top radiator mounting brackets (one on each side). The radiator sits on rubber isolator mounts at the bottom which do not require fastener removal. Inspect the rubber isolators for deterioration and replace if cracked or compressed.
9. 9

   Remove radiator from vehicle
   Carefully lift the radiator straight up and out of the engine bay, guiding it clear of the fan mounting area and any remaining hose connections. The radiator will tilt forward as it clears the lower mounting isolators. Watch for any remaining fluid spillage. Inspect the radiator core for damage, leaks, or bent fins.
10. 10

    Prepare and install new radiator
    Inspect the lower radiator mounting isolators in the vehicle and replace if deteriorated. Transfer the radiator cap to the new radiator if reusing. Position the new radiator into the engine bay, aligning the lower mounting tabs with the rubber isolators. Tilt the radiator back to vertical and ensure it seats properly on both lower mounts.
11. 11

    Install radiator mounting hardware
    Install the upper radiator mounting brackets and secure with the 2 mounting bolts (one per side). Torque the mounting bolts to specification. Do not overtighten as the brackets typically secure to plastic radiator tank mounting ears.
    Torque spec

    Radiator Mount Bolts12 Nm (9 lb-ft)
12. 12

    Reconnect overflow hose and transmission cooler lines
    Connect the coolant overflow hose to the radiator neck fitting and secure with the hose clamp. Connect the coolant overflow hose to the radiator neck fitting and secure with the hose clamp. The manual-transmission-only 2008 Viper has no transmission cooler lines, so no cooler line reconnection is required.
    Torque spec

    Transmission Cooler Lines25 Nm (18 lb-ft)
13. 13

    Reinstall cooling fan assembly
    Lower the cooling fan shroud assembly into position on the radiator, aligning the mounting holes. Install the 4 mounting bolts and tighten securely. Reconnect both cooling fan electrical connectors, ensuring they lock into place. Verify the wiring harness is routed clear of fan blades and moving components.
14. 14

    Reconnect radiator hoses
    Install the lower radiator hose onto the radiator outlet, ensuring it seats fully onto the neck. Position the hose clamp over the connection and tighten to specification. Repeat for the upper radiator hose at the radiator end. Ensure both hoses are routed without kinks or interference.
    Torque spec

    Upper/Lower Hose Clamps3 Nm (2 lb-ft)
15. 15

    Refill and bleed cooling system
    Close the radiator drain petcock and torque to specification (hand tight for plastic petcock). Reconnect the negative battery terminal. Fill the cooling system with Mopar HOAT 50/50 coolant to the specified factory capacity (verify exact capacity against 2008 Viper service documentation) through the designated fill/reservoir opening. Fill slowly to allow air to escape. Once full, install the radiator cap. Start the engine and allow it to reach operating temperature with the heater on maximum. Monitor coolant level and add as needed. Check for leaks at all connections. Allow the engine to cool, then recheck coolant level and top off as needed.
    Torque spec

    Drain Petcock5 Nm (4 lb-ft)

Reassembly

1. Torque all fasteners to specification using the values provided
2. Ensure all hose clamps are positioned over the hose beads on the radiator and engine connections
3. Verify cooling fan electrical connectors are fully seated and locked
4. Double-check transmission cooler line torque if equipped

Verification

• Start engine and verify cooling fans activate when engine reaches operating temperature
• Inspect all hose connections, radiator petcock, and transmission cooler lines for leaks with engine at operating temperature
• Verify coolant level is correct after initial heat cycle and cooling period
• Check transmission fluid level after test drive if cooler lines were disconnected
• Verify heater output is normal, indicating proper coolant circulation and system fill
• Monitor temperature gauge during test drive to confirm normal operating temperature

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