Radiator Hoses - Both

Replace upper and lower radiator hoses on the 1992 Dodge Viper 8.0L V10, including coolant drain, hose removal, and system refill with air bleeding.

Warnings

Tools required

Parts

• Upper radiator hose × 1 — Mopar 4578018 or equivalent
• Lower radiator hose × 1 — Mopar 4578017 or equivalent
• Hose clamps (worm-gear type) × 4 — Use OEM specification or quality aftermarket

Fluids

• Ethylene glycol 50/50 — 24 qt

Preparation

1. Ensure engine is completely cold to the touch (minimum 2 hours cool-down after operation)
2. Park vehicle on level surface and engage parking brake
3. Place drain pan under radiator drain petcock location at lower driver side of radiator
4. Gather all replacement hoses and verify correct fitment before beginning disassembly
5. Have adequate coolant supply mixed to 50/50 specification (12 quarts concentrate + 12 quarts distilled water, or 24 quarts pre-mixed)

Procedure

1. 1

   Remove radiator cap and drain coolant
   Slowly remove the radiator cap by turning counterclockwise to release any residual pressure. Locate the drain petcock at the lower driver side of the radiator. Turn the petcock counterclockwise to open and drain coolant into the drain pan. Allow system to drain completely (approximately 10-15 minutes).
2. 2

   Remove upper radiator hose at radiator end
   Locate the upper radiator hose connection at the top passenger side of the radiator. Using flathead screwdriver or hose clamp pliers, loosen the worm-gear hose clamp by turning the clamp screw counterclockwise or squeezing the clamp tabs. Slide the clamp back along the hose away from the radiator neck. Twist the hose gently while pulling to break the seal and remove from radiator neck. Expect residual coolant spillage.
3. 3

   Remove upper radiator hose at thermostat housing end
   Follow the upper radiator hose to the thermostat housing on the engine; verify exact location against the service manual. Loosen the hose clamp at this connection using the same method as Step 2. Slide clamp back along hose, then twist and pull the hose to remove from thermostat housing neck. Remove the complete upper radiator hose assembly from the vehicle.
4. 4

   Remove lower radiator hose at radiator end
   Locate the lower radiator hose connection at the bottom driver side of the radiator. Access may require reaching from below or through the front grille area. Loosen the hose clamp and slide it back along the hose. Twist and pull the hose from the radiator outlet. Note the routing and any securing clips for reinstallation.
5. 5

   Remove lower radiator hose at water pump end
   Follow the lower radiator hose to the water pump inlet on the front of the engine block. Loosen the hose clamp at the water pump connection and slide back along the hose. Twist and pull to remove the hose from the water pump inlet. Remove the complete lower radiator hose assembly from the vehicle. Note any mounting brackets or wire tie locations.
6. 6

   Inspect and clean connection surfaces
   Inspect all four connection necks (radiator upper and lower, thermostat housing, water pump inlet) for corrosion, cracks, or damage. Use a non-marring scraper or shop towel to remove any old rubber residue, scale, or corrosion from the connection surfaces. Ensure all surfaces are clean and smooth to provide proper seal with new hoses.
7. 7

   Install new lower radiator hose
   Slide a new hose clamp onto each end of the new lower radiator hose with clamp screws positioned for easy access after installation. Install the water pump end first, pushing the hose fully onto the water pump inlet until it seats against the bead on the neck. Route the hose following the original path, then install the radiator end, pushing fully onto the radiator outlet neck. Ensure hose is fully seated at both ends before proceeding.
8. 8

   Tighten lower radiator hose clamps
   Position both hose clamps approximately 1/4 inch back from the end of each hose connection neck. Tighten the water pump clamp first, then the radiator clamp. Ensure clamps are snug but not over-tightened to avoid cutting the hose. Verify hose remains fully seated on both necks after clamp tightening.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
9. 9

   Install new upper radiator hose
   Slide a new hose clamp onto each end of the new upper radiator hose. Install the thermostat housing end first, pushing the hose fully onto the thermostat housing neck until seated. Route the hose toward the radiator following the original path, ensuring clearance from exhaust components and sharp edges. Install the radiator end, pushing fully onto the radiator neck.
10. 10

    Tighten upper radiator hose clamps
    Position both hose clamps approximately 1/4 inch back from the end of each connection neck. Tighten the thermostat housing clamp first, then the radiator clamp. Ensure clamps are snug and hoses remain fully seated. Verify adequate clearance exists between hoses and any moving components or hot surfaces.
    Torque spec

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

    Close drain petcock and begin coolant fill
    Close the radiator drain petcock by turning clockwise until hand-tight. Verify it is secure but do not over-tighten. Begin filling the cooling system through the radiator filler neck with 50/50 coolant mixture. Fill slowly to allow air to escape. Fill until coolant level reaches the bottom of the radiator neck.
    Torque spec

    Drain Petcock7 Nm (5 lb-ft)
12. 12

    Bleed air from cooling system
    With radiator cap still off, start the engine and allow it to idle. Coolant level will drop as the thermostat opens and air purges from the system. Continue adding coolant to maintain level at the bottom of the radiator neck. Run engine until the temperature gauge reaches normal operating range and coolant circulation is visible, indicating the thermostat is open; monitor fan operation per the service manual. Watch for steady coolant circulation visible in the radiator neck.
    ⚠Keep hands and tools clear of cooling fans. Fans may activate suddenly when engine reaches operating temperature.
13. 13

    Final fill and cap installation
    With engine at operating temperature and fans cycled, top off coolant to the bottom of the radiator neck. Install the radiator cap by aligning the tabs and turning clockwise until it locks into position. Allow engine to idle for an additional 2-3 minutes, then shut off. Check coolant reservoir level and add coolant if needed to bring to FULL HOT mark.

Reassembly

1. Reassembly is covered in the installation steps above
2. Ensure all hose clamps are positioned correctly and torqued to specification
3. Verify no hoses contact moving parts, sharp edges, or exhaust components
4. Confirm drain petcock is closed and secure before filling system

Verification

• Start engine and allow to reach full operating temperature while monitoring for leaks at all four hose connections
• Verify cooling fans cycle on and off properly, indicating proper coolant flow and thermostat operation
• Check for visible coolant seepage at hose connections after engine cool-down (check when cold and dry)
• Verify coolant level remains stable in reservoir at FULL HOT mark after several heat cycles
• Inspect engine bay for any coolant drips or stains after 24-48 hours of normal operation
• Squeeze radiator hoses when engine is cold to verify firm pressure, indicating proper system seal

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