Water Pump

Replace the engine water pump on a 2008 Dodge Viper 8.4L V10, requiring serpentine belt removal, coolant drain, and pump replacement with new gasket.

Warnings

Tools required

Parts

• Water pump × 1 — Mopar 05037696AB or equivalent
• Water pump gasket × 1 — Mopar 68054620AA or equivalent
• Lower radiator hose (if deteriorated) × 1 — Use OEM specification

Fluids

• Mopar HOAT coolant 50/50 — 19 qt

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level ground and engage parking brake
3. Place a large capacity drain pan (20+ quart) beneath the radiator drain location
4. Disconnect negative battery cable to prevent accidental fan activation
5. Remove engine cover if equipped by releasing retaining clips

Procedure

1. 1

   Drain cooling system
   Locate the radiator petcock drain valve at the bottom driver side of the radiator. Open the petcock and allow coolant to drain completely into the drain pan. Once drained, remove the radiator cap to ensure complete drainage. If the coolant is contaminated or more than 5 years old, plan to replace with fresh coolant rather than reusing.
   ⚠Used coolant is toxic to pets and wildlife. Store in sealed containers and dispose of properly at a recycling center.
2. 2

   Remove serpentine belt
   Locate the serpentine belt tensioner on the front of the engine. Using the serpentine belt removal tool, rotate the tensioner clockwise to relieve tension on the belt. Slip the belt off the pulleys and carefully release the tensioner. Remove the belt from the engine bay. Inspect the belt for cracks, glazing, or fraying; replace if worn.
   ℹ️Take a photo of the belt routing or refer to the underhood diagram before removal to ensure correct reinstallation.
3. 3

   Disconnect lower radiator hose
   Locate the lower radiator hose connection at the water pump inlet (lower front of pump housing). Using pliers or a hose clamp tool, release the hose clamp and slide it back along the hose. Twist the hose gently to break the seal, then pull the hose off the water pump inlet. Position the hose away from the work area. Inspect the hose end for cracks or deterioration.
   ℹ️Residual coolant will drain from the hose connection. Keep the drain pan positioned beneath the work area.
4. 4

   Disconnect heater return hose
   Locate the heater return hose connection on the water pump (typically on the upper section of the pump housing). Release the hose clamp and slide it back. Twist and pull the hose off the water pump fitting. Move the hose aside to provide clearance for pump removal.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
5. 5

   Remove water pump mounting bolts
   Locate and remove all water pump mounting bolts securing the pump to the engine block. The 8.4L V10 water pump is secured with 5 bolts around the perimeter of the pump housing. Use appropriate socket extensions to access all bolt locations. Keep bolts organized as some may be different lengths depending on their position.
   ℹ️Support the water pump with one hand as you remove the final bolt to prevent it from falling.
6. 6

   Remove water pump from engine
   Carefully pull the water pump assembly straight away from the engine block. The pump may be sealed with the gasket and require gentle prying. Use a plastic pry tool if needed, working around the perimeter to break the gasket seal. Do not pry against the sealing surface on the engine block. Remove the pump from the engine bay.
   ⚠Do not damage the sealing surface on the engine block. Scratches or gouges will cause coolant leaks.
7. 7

   Clean mounting surface
   Using a gasket scraper or plastic scraping tool, carefully remove all remnants of the old gasket from the engine block mounting surface. Ensure the surface is completely clean, flat, and free of debris. Wipe the surface with a clean, lint-free cloth. Inspect the sealing surface for any damage, deep scratches, or corrosion that could prevent proper sealing.
   ⚠Do not use abrasive pads or aggressive scraping that could damage the aluminum sealing surface.
8. 8

   Prepare new water pump
   Inspect the new water pump for shipping damage and verify it matches the old unit in mounting hole positions and hose fitting locations. Position the new gasket on the water pump flange, ensuring all bolt holes and coolant passages align correctly. Some gaskets are adhesive-backed; others may require a thin bead of RTV sealant on the pump side only (never on both sides).
   ℹ️Do not use excessive sealant. Excess can squeeze into coolant passages and cause blockages or pump damage.
9. 9

   Install new water pump
   Carefully align the new water pump with gasket to the engine block, ensuring the gasket remains properly seated. Start all 5 mounting bolts by hand to ensure proper thread engagement before tightening any bolt. Once all bolts are hand-started, tighten them in a criss-cross pattern to the specified torque of 25 Nm (18 lb-ft). This ensures even gasket compression and proper sealing.
   ⚠Over-torquing can warp the pump housing or crack the casting. Under-torquing will result in coolant leaks. Use a calibrated torque wrench.
   Torque spec

   Water Pump Bolts25 Nm (18 lb-ft)
10. 10

    Reconnect coolant hoses
    Reconnect the heater return hose to the water pump fitting, sliding it fully onto the fitting until it seats. Position the hose clamp over the hose connection area and tighten to 3 Nm (2 lb-ft), or use a new spring clamp if equipped. Reconnect the lower radiator hose to the water pump inlet in the same manner, ensuring the hose is fully seated before securing the clamp.
    ℹ️Ensure hoses are routed correctly without kinks or interference with moving components.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
11. 11

    Reinstall serpentine belt
    Route the serpentine belt around all pulleys according to the belt routing diagram (refer to photo taken during removal or underhood diagram). Rotate the belt tensioner clockwise with the serpentine belt tool, slip the belt onto the final pulley, and carefully release the tensioner to apply proper tension. Verify the belt is correctly seated in all pulley grooves.
    ⚠A misrouted belt can cause component damage, overheating, or belt failure. Double-check routing before starting engine.
12. 12

    Refill cooling system
    Close the radiator petcock drain valve. Pour Mopar HOAT 50/50 coolant into the radiator filler neck slowly to minimize air pockets. Fill until coolant reaches the base of the filler neck. If available, use a cooling system vacuum fill tool to eliminate air from the system. Fill the coolant overflow reservoir to the FULL COLD mark. Reinstall the radiator cap.
    ℹ️The V10 system holds 19 quarts total. Initial fill may take 16-17 quarts; remaining capacity is added during burping process.
13. 13

    Bleed cooling system
    Reconnect the negative battery cable. Start the engine and allow it to idle with the heater set to maximum temperature. Monitor the temperature gauge and watch for coolant circulation. As the thermostat opens (around 195°F), coolant level in the radiator may drop. Shut off the engine, allow it to cool slightly, remove the radiator cap carefully, and add coolant as needed. Repeat this process 2-3 times until the coolant level stabilizes and no air bubbles are visible. Top off the overflow reservoir to the FULL HOT mark when engine is at operating temperature.
    ⚠️Never remove the radiator cap when the engine is at full operating temperature. Allow cooling between checks to avoid burns from hot coolant.
    ⚠Monitor the temperature gauge closely during the first few heat cycles. If the gauge climbs into the red zone, shut off the engine immediately and recheck for air pockets or leaks.

Reassembly

1. Reinstall engine cover if removed, ensuring all clips are fully engaged
2. Check for coolant leaks around the water pump, hose connections, and radiator petcock
3. Verify serpentine belt tension and alignment on all pulleys
4. Allow engine to complete several full heat cycles over the next few days and recheck coolant level

Verification

• Start engine and verify no coolant leaks are visible around water pump gasket or hose connections after reaching operating temperature
• Confirm temperature gauge reads normal operating range (approximately halfway) and does not fluctuate erratically
• Verify heater produces hot air at idle, indicating proper coolant circulation
• Check coolant overflow reservoir level is at FULL HOT mark with engine at operating temperature
• Inspect serpentine belt for proper tension and alignment on all pulleys with engine running
• Listen for any unusual noises from the water pump bearing (squealing or grinding indicates pump failure)
• After test drive, recheck coolant level and inspect for leaks when engine is cool

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