Radiator Removal and Service

This procedure covers the complete removal and reinstallation of the radiator on a 2007 Ram 3500 with the 5.9L Cummins diesel engine, including draining coolant, disconnecting hoses and transmission lines, and removing the fan shroud.

Warnings

Tools required

Parts

• Radiator (if replacing) × 1 — OEM or aftermarket equivalent for 5.9L Cummins
• Upper radiator hose (if damaged) × 1 — Use OEM specification
• Lower radiator hose (if damaged) × 1 — Use OEM specification
• Hose clamps × 4 — Worm gear type, various sizes
• Transmission cooler line washers × 4 — Copper crush washers
• HOAT coolant concentrate × 2 — Mopar HOAT or equivalent

Fluids

• HOAT coolant 50/50 — 28 qt

Preparation

1. Park vehicle on level ground and apply parking brake
2. Allow engine to cool completely for at least 2 hours if recently operated
3. Disconnect negative battery cable to prevent fan clutch activation
4. Remove engine cover if equipped
5. Place large drain pan under radiator drain petcock

Procedure

1. 1

   Drain cooling system
   Locate the radiator drain petcock/plug at the lower corner of the radiator (verify side against service manual; if no petcock is present, drain via the lower radiator hose). Carefully open the drain petcock by turning counterclockwise by hand only. Allow coolant to drain completely into the drain pan. Once drained, hand-tighten the petcock only - do not use tools.
   Torque spec

   Drain Petcock5 Nm (4 lb-ft)
2. 2

   Remove upper radiator hose
   Using hose clamp pliers, compress and slide the clamp back on the upper radiator hose at the radiator connection. Twist the hose gently to break the seal, then pull the hose off the radiator neck. Position the hose upward to minimize coolant spillage.
3. 3

   Remove lower radiator hose
   Locate the lower radiator hose connection at the bottom of the radiator on the passenger side. Compress and slide back the hose clamp, twist the hose to break the seal, and remove from the radiator. Allow any remaining coolant to drain into the pan.
4. 4

   Disconnect transmission cooler lines
   If equipped with automatic transmission, locate the two transmission cooler lines connected to the radiator tank (verify side against the service manual). Position a drain pan beneath the connections. Determine whether the cooler line fittings are threaded or quick-connect type. For threaded fittings, use a flare nut wrench to loosen and remove them and replace any crush washers; for quick-connect fittings, depress the release collar/clip and pull the line free. Cap or plug the lines immediately to prevent dirt contamination and excessive fluid loss.
   Torque spec

   Transmission Cooler Lines25 Nm (18 lb-ft)
5. 5

   Remove overflow hose
   Locate the overflow hose connected to the radiator neck or overflow tank fitting. Compress the hose clamp and slide it back, then pull the overflow hose off the radiator fitting.
6. 6

   Remove fan shroud upper bolts
   Locate the upper fan shroud mounting bolts at the top edge of the shroud (typically 2-4 bolts). Remove these bolts completely and set aside. The fan shroud will remain loosely in place supported by the lower tabs.
   Torque spec

   Fan Shroud Bolts10 Nm (7 lb-ft)
7. 7

   Tilt fan shroud back
   Carefully tilt the top of the fan shroud rearward toward the engine. The shroud may need to be lifted slightly to clear the lower retaining tabs. Rest the shroud against the engine, ensuring the mechanical fan blades are clear of the shroud and will not contact it during radiator removal.
8. 8

   Remove radiator mounting bolts
   Locate the radiator mounting bolts at the top corners of the radiator (typically 2 bolts through plastic mounting brackets). Remove both radiator mount bolts completely. Note the position of any spacers or rubber isolators for reinstallation.
   Torque spec

   Radiator Mount Bolts12 Nm (9 lb-ft)
9. 9

   Remove radiator from vehicle
   Carefully lift the radiator straight up and out of the engine bay. The radiator will have lower locating pins or tabs that must clear the mounting brackets at the bottom of the core support. Tilt the top of the radiator toward the engine slightly as you lift to clear the fan assembly. Once clear of the vehicle, inspect the radiator for damage, debris, and cooling fin condition.
10. 10

    Inspect and clean mounting area
    With the radiator removed, inspect the radiator support and mounting brackets for damage or corrosion. Clean any debris from the lower mounting tabs and grille opening. Check rubber isolators and mounting hardware for deterioration and replace if necessary. Inspect the condition of all hoses and clamps while accessible.

Reassembly

1. Install radiator by reversing removal procedure, ensuring lower mounting pins seat properly in brackets
2. Install radiator mounting bolts and torque to specification - do not overtighten plastic mounts
3. Position fan shroud back into place, ensuring lower tabs engage properly before installing upper bolts
4. Torque fan shroud bolts to specification
5. Install transmission cooler lines with new copper washers and torque to specification using flare nut wrench
6. Install lower radiator hose with new clamp positioned 1/4 inch from hose end
7. Install upper radiator hose with new clamp positioned 1/4 inch from hose end
8. Reconnect overflow hose to radiator
9. Fill cooling system with 50/50 HOAT coolant mixture using proper fill procedure for diesel engines to avoid air pockets
10. Reconnect negative battery cable
11. Reinstall engine cover if equipped

Verification

• Start engine and allow to reach operating temperature while monitoring for leaks at all hose connections and transmission cooler line fittings
• Verify cooling fan operation and check that shroud does not contact fan blades
• Check coolant level in overflow tank when engine is fully warmed up - add coolant if necessary
• Pressurize cooling system to 15 PSI using a cooling system pressure tester and check for leaks if radiator was replaced
• Verify transmission fluid level is correct after test drive if cooler lines were disconnected - top off as needed
• Inspect under vehicle for any coolant or transmission fluid drips after 24 hours of operation

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