Heater Hoses

Replace heater hoses on the 1992 Dodge Viper's 8.0L V10 engine, including inlet and outlet hoses connecting the engine to the heater core.

Warnings

Tools required

Parts

• Heater inlet hose × 1 — Use OEM specification or Gates 19262
• Heater outlet hose × 1 — Use OEM specification or Gates 19263
• Hose clamps (worm-drive or spring type) × 4 — Typically 1.25-1.5 inch diameter
• Coolant (ethylene glycol 50/50) × 2 — Mopar OEM or equivalent

Fluids

• coolant — 2 qt

Preparation

1. Ensure engine is completely cold to the touch (minimum 2 hours after last operation).
2. Park vehicle on level surface and engage parking brake.
3. Place drain pan beneath radiator drain petcock.
4. Remove radiator cap slowly to release any residual pressure.
5. Locate heater hoses at rear of engine block (driver side) running to firewall heater core connections.

Procedure

1. 1

   Drain cooling system
   Open radiator drain petcock at bottom of radiator and drain coolant into collection pan (verify petcock location against 1992 Viper service manual). Drain approximately 3-4 gallons to drop coolant level below heater core height. This prevents excessive spillage when disconnecting heater hoses. Close petcock when draining slows to a trickle. Note: Use OEM specification (verify against Mopar parts catalog for 1992 Viper heater inlet hose) Note: Use OEM specification (verify against Mopar parts catalog for 1992 Viper heater outlet hose)
   Torque spec

   Drain Petcock7 Nm (5 lb-ft)
2. 2

   Access heater hoses at engine side
   Locate the two heater hose connections at the rear of the engine block on the driver side of the V10. The two heater hoses connect to fittings at the engine (verify inlet/outlet assignment and hose diameters against the 1992 Viper service manual). Note routing and orientation of both hoses before removal. Note routing and orientation of both hoses before removal.
3. 3

   Remove engine-side hose clamps
   Using hose clamp pliers or flathead screwdriver, loosen the hose clamps securing both heater hoses to the engine block fittings. For worm-drive clamps, rotate clamp to position screw head for access and back out screw several turns. For spring clamps, compress ears and slide clamp back along hose at least 2 inches from fitting. Have shop towels ready to catch residual coolant.
4. 4

   Disconnect hoses from engine block
   Twist each heater hose back and forth while pulling away from engine block fitting to break seal. If hoses are stuck due to age, carefully insert a thin flathead screwdriver or razor blade between hose and fitting to break adhesion. Do not gouge or damage the metal fittings. Allow remaining coolant in hoses to drain into pan. Expect approximately 1 quart of coolant to spill from hoses and fittings.
5. 5

   Access heater core connections at firewall
   From inside engine bay, locate where heater hoses pass through firewall to heater core (passenger side of firewall near blower motor area). Access is tight; work may require reaching over valve covers. Identify the clamps securing hoses to heater core inlet/outlet tubes protruding through firewall.
6. 6

   Remove firewall-side hose clamps
   Loosen hose clamps at heater core tubes using same method as engine side. Due to tight access, a flexible hose clamp tool may be helpful. Slide clamps back from fittings to allow hose removal. Place shop towels around fittings to catch any remaining coolant.
7. 7

   Remove old heater hoses
   Twist and pull heater hoses off firewall heater core tubes. If hoses are bonded to tubes, carefully cut hose lengthwise with razor blade and peel away in sections to avoid damaging heater core tubes. Note exact routing of hoses through engine bay, including any support brackets or clips. Remove and retain any mounting clips or guides for reinstallation.
8. 8

   Inspect and clean fittings
   Inspect all four connection points (two engine block, two heater core) for corrosion, damage, or debris. Clean fittings with wire brush if deposits are present. Check heater core tubes at firewall for cracks or damage. Verify fittings are smooth with no sharp edges that could cut new hoses. Wipe all fittings clean with shop towels.
9. 9

   Install new heater hoses at firewall
   Starting at firewall, slide new hose clamps onto new heater hoses before installation. Position inlet hose (match diameter to fitting) onto heater core inlet tube and outlet hose onto outlet tube. Push hoses fully onto tubes until they bottom out against firewall (typically 1.5-2 inches of insertion). Slide clamps into position 0.5 inch from end of hose, centered over fitting ridge if present.
10. 10

    Route hoses through engine bay
    Route new heater hoses through engine bay following exact path of original hoses. Ensure hoses do not contact exhaust manifolds, sharp edges, or moving components. Reinstall any routing clips or support brackets removed earlier. Allow sufficient slack to prevent tension when engine moves on mounts, but avoid excessive sagging that could cause rubbing.
11. 11

    Connect hoses to engine block
    Slide hose clamps onto free ends of heater hoses. Connect inlet hose to engine block inlet fitting and outlet hose to outlet fitting. Push hoses fully onto fittings until they seat completely. Position clamps 0.5 inch from end of each hose, centered over fitting bead or ridge.
12. 12

    Tighten all hose clamps
    Tighten all four hose clamps securely. For worm-drive clamps, tighten firmly by hand until snug against the hose without crushing it; no specific torque value is published for these heater hose clamps. For spring clamps, ensure they are fully seated in locked position. Verify each hose cannot be twisted or pulled off fitting by hand. Double-check all clamp positions are centered over fitting ridges.
13. 13

    Refill cooling system
    Using coolant funnel in radiator fill neck, slowly add 50/50 ethylene glycol coolant mixture. Fill radiator to neck, then start engine and allow to idle with heater set to maximum heat. Add coolant as level drops during system burping. Monitor heater hose connections for leaks. Continue until coolant level stabilizes and heater produces hot air. Top off to cold fill line and install radiator cap.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)

Reassembly

1. Verify all four hose clamps are properly positioned and tightened to spec.
2. Confirm heater hoses do not contact any hot or moving engine components.
3. Ensure coolant system is filled to proper level and all air is purged.

Verification

• Start engine and bring to operating temperature while monitoring coolant level.
• Check all four heater hose connections for leaks with engine at idle and at 2000 RPM.
• Verify heater produces hot air inside cabin when set to maximum heat.
• Inspect engine bay for coolant drips or wetness around hose connections after 10-minute test drive.
• Recheck coolant level when engine is cold (next day) and top off if necessary.

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