Heater Hoses

This procedure covers removal and replacement of heater hoses on a 2005 Dodge Viper 8.3L V10, including coolant drain, hose removal from engine connections and heater core, and system refill.

Warnings

Tools required

Parts

• Heater inlet hose × 1 — OEM or Gates equivalent for 8.3L V10
• Heater outlet hose × 1 — OEM or Gates equivalent for 8.3L V10
• Worm gear hose clamps (1.5-2.0 inch) × 4 — Use OEM specification or stainless steel replacement

Fluids

• Zerex G-05 HOAT 50/50 coolant — 3 qt

Preparation

1. Ensure engine is completely cold to the touch (minimum 2 hours after last operation).
2. Place vehicle on level ground and engage parking brake.
3. Position drain pan under radiator petcock on driver side lower radiator tank.
4. Remove radiator cap slowly to release any residual pressure.
5. Have replacement hoses, clamps, and coolant ready before beginning disassembly.

Procedure

1. 1

   Drain cooling system
   Open radiator petcock at lower driver side of radiator and drain coolant into pan. Once flow stops, inspect drained coolant for contamination or debris. If coolant is clean and less than 2 years old, it may be reused after filtration; otherwise dispose properly and use fresh coolant. Close petcock after draining.
2. 2

   Access heater hose connections at firewall
   Locate the two heater hoses penetrating the firewall on the passenger side of the engine bay. Note the routing of both heater hoses as they penetrate the firewall; verify the specific inlet and outlet connection points against the factory service manual before removal. Remove any wire loom clips or plastic retainers securing hoses to the firewall or fender structure using a flat blade screwdriver. Note routing for reinstallation.
3. 3

   Remove heater inlet hose at water pump connection
   Trace the upper heater hose forward to its engine-side fitting; verify the exact connection location (water pump, coolant crossover, or head fitting) against the factory service manual before disconnecting. Using hose clamp pliers or flat blade screwdriver, loosen the worm gear clamp at the water pump fitting. Slide clamp back along hose away from connection point. Twist hose gently to break seal, then pull firmly to remove from fitting. If hose is stuck, use hose removal tool or carefully cut hose lengthwise to remove without damaging fitting.
4. 4

   Remove heater outlet hose at thermostat housing
   Locate the lower heater hose engine-side connection; verify the exact fitting location against the factory service manual before disconnecting. Loosen the worm gear clamp and slide it back along the hose. Twist and pull hose to remove from fitting. If necessary, use hose removal tool to work hose off stubborn connection without damaging aluminum housing.
5. 5

   Disconnect hoses at firewall heater core connections
   Working from inside the engine bay at the firewall, loosen the worm gear clamps on both heater hoses at the heater core tube connections. Slide clamps back and remove both hoses from the heater core tubes. Expect residual coolant to drain from hoses and heater core tubes; have shop towels ready. Cap or plug heater core tubes temporarily if replacement hoses are not immediately available to prevent debris entry.
6. 6

   Inspect fittings and clean mating surfaces
   Inspect all four connection points (water pump, thermostat housing, and both heater core tubes at firewall) for corrosion, damage, or residue buildup. Use wire brush to clean any corrosion or old hose material from metal fittings. Ensure fittings are smooth and free of burrs that could damage new hoses. Check heater core tubes for leaks or damage; replace heater core if tubes are corroded or cracked.
7. 7

   Install new heater inlet hose
   Route new heater inlet hose from the water pump connection to the upper heater core tube at the firewall, following the original path noted during removal. Slide a new worm gear clamp onto each end of the hose before installation. Push hose firmly onto water pump fitting until it seats completely (typically 1.5-2 inches onto barb). Repeat at heater core tube connection. Position clamps 0.5 inch from end of each hose, centered over the barb, and tighten securely.
8. 8

   Install new heater outlet hose
   Route new heater outlet hose from the lower heater core tube at firewall to the thermostat housing connection, matching original routing. Install new worm gear clamps on both ends before connecting. Seat hose fully onto thermostat housing fitting and onto heater core tube. Position clamps properly and tighten to specification.
9. 9

   Secure hoses and restore wire loom clips
   Reinstall any plastic retainers or wire loom clips that secure heater hoses to firewall or fender structure. Ensure hoses do not contact sharp edges, hot exhaust components, or moving parts. Hoses should have slight slack to allow for engine movement without strain on connections.
10. 10

    Refill cooling system
    Fill cooling system with the factory-specified coolant (verify HOAT/G-05 or equivalent per the 2005 Viper service manual) at 50/50 concentration through radiator filler neck. Fill slowly to allow air to escape. Add coolant until level reaches bottom of filler neck. Install radiator cap. Start engine and allow to warm to operating temperature (thermostat open, both heater hoses hot to touch). Monitor coolant level and temperature gauge. Add coolant as needed to maintain proper level. Check all four heater hose connections for leaks while engine is at operating temperature.
11. 11

    Bleed air from system and verify operation
    With engine at operating temperature, turn heater control to maximum heat and fan on high. Verify hot air output from cabin vents, confirming coolant flow through heater core. Rev engine to 2000 RPM several times to help purge trapped air. After engine cools, recheck coolant level in radiator and top off if necessary. Inspect all heater hose connections once more for seepage or leaks.

Reassembly

1. Installation mirrors removal with emphasis on correct hose routing to avoid contact with hot or moving components.
2. Ensure all hose clamps are positioned over the barbed sections of fittings, not on smooth tube portions.
3. After initial heat cycle, recheck coolant level when engine is cold and top off as needed; air pockets may cause initial level drop.

Verification

• Start engine and verify no coolant leaks at any of the four heater hose connections (water pump, thermostat housing, two heater core tubes).
• Confirm heater produces hot air in cabin within 5-10 minutes of cold start, indicating proper coolant circulation.
• Check coolant level after first drive cycle and top off if necessary; system may require additional fluid as air is purged.
• Inspect under vehicle and in engine bay for coolant drips or stains after 24 hours of operation.
• Verify engine temperature remains in normal range (190-210°F) and does not overheat.

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