Radiator Hose - Upper

This procedure covers removal and replacement of the upper radiator hose on a 2007 Ram 3500 with the 5.9L Cummins diesel engine.

Warnings

Tools required

Parts

• Upper radiator hose × 1 — Use OEM specification
• Worm gear hose clamps (if reusing originals show damage) × 2 — 44mm-57mm range typical

Fluids

• HOAT coolant 50/50 — 2 qt

Preparation

1. Ensure engine is completely cold to the touch before beginning work
2. Park vehicle on level ground and engage parking brake
3. Place drain pan beneath radiator drain petcock location
4. Open hood and secure in upright position

Procedure

1. 1

   Relieve cooling system pressure
   Slowly rotate the coolant reservoir (degas bottle) pressure cap counterclockwise to the first stop and allow any residual pressure to vent completely. Once pressure is released, press down and continue rotating to remove the cap completely.
2. 2

   Drain coolant from system
   Locate the radiator drain petcock at the lower corner of the radiator (verify exact side against factory documentation). Position your drain pan directly beneath it. Open the petcock by turning counterclockwise and allow approximately 2-3 quarts to drain. This will lower the coolant level below the upper hose connection point. You do not need to drain the entire system.
3. 3

   Remove upper hose clamp at radiator
   Locate the upper radiator hose connection at the top passenger side of the radiator. Using hose clamp pliers or standard pliers, compress or loosen the worm gear clamp securing the hose to the radiator neck. Slide the clamp back along the hose at least 2-3 inches away from the radiator connection point.
4. 4

   Disconnect hose from radiator
   Twist the upper radiator hose back and forth while pulling away from the radiator neck to break the seal. If the hose is stuck, carefully use a flathead screwdriver to gently pry between the hose and radiator neck to break the seal. Be careful not to damage the radiator neck. Residual coolant will drain from the hose.
5. 5

   Remove upper hose clamp at thermostat housing
   Follow the upper radiator hose to the engine thermostat housing located on the driver side front of the engine block. Using hose clamp pliers or standard pliers, loosen the worm gear clamp at this connection and slide it back along the hose away from the thermostat housing.
6. 6

   Remove upper radiator hose
   Twist and pull the hose from the thermostat housing connection to break the seal. Remove the hose completely from the vehicle. Inspect both connection points on the radiator and thermostat housing for any cracks, damage, or excessive corrosion. Clean both surfaces with a shop towel if debris is present.
7. 7

   Install new upper radiator hose
   Position the hose clamps on the new upper radiator hose with one clamp at each end, positioned approximately 1 inch from each end. Connect the hose first to the thermostat housing on the engine, pushing firmly until fully seated. Then route the hose to the radiator and push the opposite end onto the radiator neck until fully seated. Ensure the hose routing does not contact any sharp edges, belts, or moving components.
8. 8

   Secure hose clamps
   Slide both hose clamps into position over the connection points, centering each clamp approximately 1/2 inch from the end of each hose. Tighten each worm gear clamp securely using pliers or screwdriver. The clamp should be tight enough to prevent leaks but not so tight that it cuts into the hose material.
9. 9

   Close radiator drain and refill coolant
   Close the radiator drain petcock by turning clockwise until snug (hand-tight only). Using a funnel, slowly pour HOAT 50/50 coolant mixture into the coolant reservoir (degas bottle) until the level reaches the appropriate fill mark. Pause periodically to allow air bubbles to escape. Add coolant slowly to minimize trapped air in the system.
10. 10

    Burp cooling system
    With the reservoir cap still off, start the engine and allow it to idle. Watch the coolant level in the reservoir (degas bottle) and add coolant as needed as air purges from the system. Once the thermostat opens (verify opening temperature against factory specification, typically around 190°F), the coolant level will drop slightly. Continue adding coolant to maintain proper level. Run engine until cooling fan cycles on and off at least once.
11. 11

    Complete fill and cap system
    With engine running at normal operating temperature, top off the coolant reservoir (degas bottle) to the appropriate mark. Install the reservoir pressure cap by pressing down and rotating clockwise until it locks into place. Verify the coolant is at the FULL COLD mark once the engine cools. Shut off engine.

Reassembly

1. No additional reassembly required for this procedure

Verification

• Visually inspect both hose connections for any signs of coolant leakage
• Check coolant level in overflow reservoir after engine cools and top off to FULL COLD mark if necessary
• Start engine and verify no leaks at upper radiator hose connections during warm-up cycle
• Verify heater produces hot air indicating proper coolant circulation
• After first drive cycle, recheck coolant level when cold and top off if needed
• Monitor coolant level and temperature gauge over the next few days to ensure system is properly filled and no leaks are present

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