Radiator

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

Warnings

Tools required

Parts

• Radiator assembly × 1 — Use OEM specification or equivalent
• Upper radiator hose (if damaged) × 1 — Use OEM specification
• Lower radiator hose (if damaged) × 1 — Use OEM specification
• Radiator drain plug O-ring × 1 — Use OEM specification
• Hose clamps (if reusing old clamps) × 4 — Worm-gear type, various sizes

Fluids

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

Preparation

1. Ensure engine is completely cold (minimum 2 hours after last operation).
2. Park vehicle on level ground and apply parking brake.
3. Raise front of vehicle using floor jack and support on jack stands at manufacturer-recommended lift points.
4. Remove front undertray or splash shield if equipped to access radiator drain plug.
5. Position large drain pan beneath radiator drain plug location (driver side bottom of radiator).

Procedure

1. 1

   Drain cooling system
   Slowly loosen the radiator cap to release any residual pressure, then remove completely. Locate the radiator drain petcock on the driver side lower corner of the radiator. Open the drain valve and allow coolant to drain completely into the pan. Remove the drain plug completely to ensure full drainage. Replace the drain plug O-ring with a new one before reinstallation.
   Torque spec

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

   Disconnect battery negative terminal
   Disconnect the negative battery cable to prevent any electrical issues during radiator removal. Use a 10mm socket to loosen the terminal clamp nut. Move the cable away from the battery post and secure it so it cannot make contact.
3. 3

   Remove upper radiator hose
   Using hose clamp pliers, release the spring clamp or loosen the worm-gear clamp securing the upper radiator hose to the radiator inlet. Twist the hose gently to break the seal, then pull it free from the radiator neck. Be prepared for residual coolant spillage. Inspect the hose for cracks or deterioration and replace if necessary.
   Torque spec

   Upper/Lower Hose Clamps3 Nm (2 lb-ft)
4. 4

   Remove lower radiator hose
   Access the lower radiator hose connection at the bottom of the radiator. Release the clamp using hose clamp pliers and twist the hose to break the seal. Pull the hose free from the radiator outlet. Allow any remaining coolant to drain into the pan. Inspect the hose condition.
   Torque spec

   Upper/Lower Hose Clamps3 Nm (2 lb-ft)
5. 5

   Disconnect transmission cooler lines
   The 2005 Dodge Viper is equipped exclusively with a manual transmission (Tremec T56 6-speed) and has no automatic transmission cooler lines connected to the radiator. Skip this step entirely — there are no cooler line fittings to disconnect.
   ℹ️Approximately 1-2 ounces of transmission fluid will drain from the lines. This is normal and does not require a full transmission fluid refill.
   Torque spec

   Transmission Cooler Lines25 Nm (18 lb-ft)
6. 6

   Remove fan shroud upper mounting bolts
   Locate the 2 upper fan shroud mounting bolts securing the plastic fan shroud to the radiator support. These are positioned at the top left and right corners of the shroud. Remove both bolts using a 10mm socket. Leave the shroud in place for now; it will be lifted out with the radiator as an assembly. Note the electric fan(s) are mounted to the shroud — ensure the fan electrical connector is disconnected before removal.
7. 7

   Remove fan shroud lower clips
   The lower portion of the fan shroud is secured to the radiator by plastic clips rather than bolts. Reach down and disengage the lower clips by squeezing or prying them gently with a flat-blade screwdriver. The shroud should now be free but will remain in position around the mechanical fan.
8. 8

   Remove radiator mounting bolts
   Locate the 4 radiator mounting bolts that secure the radiator to the radiator support frame. These are positioned at the top corners of the radiator assembly. Remove all 4 bolts using a 10mm socket. Keep these bolts organized as they will be reused with the new radiator mounting brackets.
   ⚠The radiator mounting points use plastic isolators. Do not overtighten bolts during reinstallation or the mounts will crack.
   Torque spec

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

   Remove radiator and shroud assembly
   Carefully tilt the top of the radiator toward the engine while lifting upward to clear the lower mounting pins or guides. The fan shroud with its electric fan(s) will lift out simultaneously with the radiator. Ensure the fan electrical connector has been disconnected, then lift the radiator and shroud assembly up and out of the engine bay. Separate the fan shroud from the radiator once removed.
10. 10

    Transfer components to new radiator
    If the new radiator does not include mounting brackets, transfer the rubber isolator mounts and any brackets from the old radiator to the new unit. Inspect all rubber isolators for cracking or compression damage and replace if necessary. Install the drain petcock into the new radiator with a new O-ring, torquing to specification by hand tightness.
    Torque spec

    Drain Petcock5 Nm (4 lb-ft)
11. 11

    Install radiator and shroud assembly
    Carefully lower the radiator and shroud assembly (with its electric fan[s]) into the engine bay as a unit. Guide the radiator down onto the lower mounting pins or guides, then reconnect the fan electrical connector. Align the upper mounting holes with the radiator support brackets. Engage the lower shroud clips first, then install the 4 radiator mounting bolts hand-tight.
    Torque spec

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

    Secure fan shroud and radiator
    Install the 2 upper fan shroud mounting bolts and tighten to secure the shroud to the radiator. Verify the lower clips are fully engaged. Torque the 4 radiator mounting bolts to specification. Do not overtighten as this will damage the plastic isolator mounts.
    Torque spec

    Radiator Mount Bolts12 Nm (9 lb-ft)
13. 13

    Reconnect transmission cooler lines
    The 2005 Dodge Viper is manual transmission only and has no transmission cooler lines at the radiator. Skip this step entirely.
    Torque spec

    Transmission Cooler Lines25 Nm (18 lb-ft)
14. 14

    Install lower radiator hose
    Slide a new hose clamp onto the lower radiator hose if replacing the clamp. Push the hose firmly onto the radiator outlet until it seats completely. Position the clamp approximately 1/2 inch from the end of the hose and tighten to specification.
    Torque spec

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

    Install upper radiator hose
    Slide a new hose clamp onto the upper radiator hose if replacing the clamp. Push the hose firmly onto the radiator inlet neck until fully seated. Position the clamp approximately 1/2 inch from the end of the hose and tighten to specification.
    Torque spec

    Upper/Lower Hose Clamps3 Nm (2 lb-ft)
16. 16

    Refill cooling system
    Ensure the radiator drain petcock is closed and torqued to specification. Using a funnel, slowly pour Zerex G-05 HOAT 50/50 coolant into the radiator until it reaches the base of the filler neck. Allow time for air bubbles to escape. Verify the exact cooling system capacity in the factory service manual before filling; do not assume 19 quarts. Fill gradually to the correct specified capacity. Locate and open the coolant bleed valve on the thermostat housing or highest point in the system to purge air while filling. Once coolant flows from the bleed valve without air bubbles, close the valve.
    ℹ️Fill slowly to prevent air pockets from forming in the system. The V10 engine has multiple high points where air can become trapped.
17. 17

    Reconnect battery and pressure test
    Reconnect the negative battery cable and tighten the terminal clamp. Install the radiator cap. Start the engine and allow it to reach operating temperature while monitoring for leaks at all connection points. Watch the temperature gauge to ensure proper thermostat operation and coolant circulation. Turn the heater to maximum heat and verify hot air output, confirming air has been purged from the heater core. Shut off the engine and allow it to cool for 15 minutes, then recheck the coolant level and top off if necessary.

Reassembly

1. Reinstall the front undertray or splash shield if removed during preparation.
2. Remove jack stands and lower vehicle to the ground.
3. After the first drive cycle, recheck coolant level when engine is cold and top off as needed. Air pockets may continue to purge during the first few heat cycles.
4. Inspect all hose connections and transmission cooler line fittings for leaks after 24 hours of operation.

Verification

• Verify no coolant leaks are present at radiator hose connections, drain petcock, or transmission cooler line fittings.
• Confirm engine reaches normal operating temperature (approximately 195-210°F) without overheating.
• Verify heater produces hot air at maximum heat setting, indicating proper coolant circulation and air purge.
• Check coolant level in radiator when cold and top off if necessary.
• Inspect transmission fluid level if cooler lines were disconnected, though minimal fluid loss should occur.

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