Radiator

This procedure covers removal and replacement of the radiator on a 1994-2007 Dodge Ram 2500 with the 5.9L Cummins diesel engine and 4WD, including coolant system draining, hose and transmission cooler line disconnection, fan shroud removal, and refilling.

Warnings

Tools required

Parts

• Radiator (2500 4x4 diesel specific) × 1 — Use OEM specification
• Upper radiator hose × 1 — Replace if cracked or brittle
• Lower radiator hose × 1 — Replace if cracked or brittle
• Radiator cap × 1 — Replace if over 5 years old
• Hose clamps (assorted) × 4 — Replace if corroded
• Transmission cooler line O-rings × 2 — If equipped with quick-disconnect fittings

Fluids

• Ethylene glycol 50/50 coolant — 28 qt

Preparation

1. Ensure the engine is completely cold before starting work
2. Park vehicle on level ground and engage parking brake
3. Disconnect negative battery cable to prevent fan engagement
4. Place drain pan(s) underneath radiator drain petcock location
5. Remove the engine cover if equipped (requires removing two hold-down bolts)
6. Document transmission cooler line routing with photos if equipped with automatic transmission

Procedure

1. 1

   Drain the cooling system
   Slowly loosen the radiator cap to relieve any residual pressure. Remove the cap completely. Locate the radiator drain petcock on the lower driver's side of the radiator. Using hand pressure only, open the petcock by turning counterclockwise and allow coolant to drain into the catch pan. If the petcock is stuck or damaged, remove the lower radiator hose instead. Allow system to drain completely (approximately 10-15 minutes).
   Torque spec

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

   Disconnect radiator hoses
   Using hose clamp pliers or flathead screwdriver, loosen the clamps on the upper and lower radiator hoses at the radiator connections. Twist the hoses to break them free from the radiator necks, then pull them off. If hoses are stuck, carefully use a thin flathead screwdriver to break the seal without damaging the radiator neck. Inspect hoses for cracks, swelling, or brittleness and replace if necessary.
3. 3

   Disconnect overflow hose
   Locate the overflow hose connected to the radiator neck (passenger side near top). Loosen the clamp and remove the hose from the radiator. Note the orientation and routing for reinstallation.
4. 4

   Remove fan shroud bolts
   The mechanical fan shroud must be removed with the radiator. Locate the upper fan shroud mounting fasteners (typically 2 bolts/nuts along the top edge; verify count for your model). Remove these fasteners using the appropriate socket. Allow the fan shroud to rest on the fan blades but do not remove it completely yet. On some models, there may be lower tabs that need to be lifted out of slots in the radiator support.
   ⚠The mechanical fan has sharp metal blades. Work carefully to avoid cuts when working around the fan shroud.
5. 5

   Disconnect transmission cooler lines
   If equipped with automatic transmission, locate the transmission cooler lines connected to the right (passenger) side of the radiator. These may be threaded fittings or quick-disconnect types. For threaded fittings, use a flare nut wrench to loosen the fittings at the radiator to prevent rounding. For quick-disconnect types, press the release tabs and pull the lines straight out. Have a catch pan ready as residual fluid will drain. Cap or plug the lines and radiator fittings to prevent contamination.
   ℹ️Some transmission fluid loss is normal. Check and top off transmission fluid after completing the repair.
   Torque spec

   Transmission Cooler Lines25 Nm (18 lb-ft)
6. 6

   Remove radiator mounting hardware
   Locate the radiator mounting bolts or brackets. On most Ram 2500 models, there are two upper mounting bolts that thread into rubber isolators on the radiator support. Remove these bolts. The lower radiator mounts typically use rubber isolator pins that the radiator sits on; these do not require removal.
7. 7

   Remove radiator and fan shroud assembly
   Carefully lift the radiator straight up and out of the engine bay. The fan shroud will come out with the radiator. Tilt the top of the radiator toward the engine slightly to clear the fan blades and shroud, then lift straight up. This is a heavy assembly; use proper lifting technique and consider having an assistant help. Once clear of the vehicle, separate the fan shroud from the radiator by lifting it off the mounting tabs.
8. 8

   Inspect and clean mounting area
   Inspect the radiator support and mounting locations for damage, corrosion, or debris. Clean the rubber isolator mounts on the radiator support. Check that the lower rubber isolator pins are in good condition and properly seated. Inspect the transmission cooler lines for damage or corrosion. Clean any coolant residue from the area.
9. 9

   Prepare new radiator
   Inspect the new radiator for shipping damage, especially to the fins and mounting tabs. Transfer the drain petcock to the new radiator if not pre-installed, hand tightening only. If reusing the fan shroud, inspect it for cracks and ensure mounting tabs are intact. Position the fan shroud onto the new radiator, ensuring it seats properly on the mounting tabs.
   Torque spec

   Drain Petcock5 Nm (4 lb-ft)
10. 10

    Install radiator assembly
    With the fan shroud loosely attached to the radiator, carefully lower the radiator and shroud assembly into the engine bay. Guide the bottom of the radiator onto the rubber isolator pins first. Tilt the assembly as needed to clear the fan blades. Ensure the radiator is fully seated on both lower mounts and is centered in the radiator support opening.
11. 11

    Secure radiator and fan shroud
    Install the upper radiator mounting bolts through the mounting brackets and thread into the radiator support. Tighten to specification. Ensure the radiator is sitting squarely and is not tilted. Install the upper fan shroud mounting bolts and tighten securely, but do not overtighten plastic components. Verify the fan shroud is properly positioned and does not contact the fan blades at any point.
12. 12

    Reconnect transmission cooler lines
    If equipped with automatic transmission, reconnect the transmission cooler lines to the radiator. For quick-disconnect fittings, install new O-rings if provided, then push the lines firmly into the radiator until they click. Tug gently to verify they are locked. For threaded fittings, thread by hand first to ensure proper engagement, then tighten to specification using a flare nut wrench.
    Torque spec

    Transmission Cooler Lines25 Nm (18 lb-ft)
13. 13

    Reconnect radiator hoses
    Install new hose clamps on the upper and lower radiator hoses if replacing. Slide the upper radiator hose onto the radiator neck and engine thermostat housing, ensuring it is fully seated. Position clamps beyond the bead on each neck and tighten to specification. Repeat for the lower radiator hose. Reconnect the overflow hose to the radiator neck and secure with its clamp.
    Torque spec

    Upper/Lower Hose Clamps3 Nm (2 lb-ft)
14. 14

    Fill cooling system
    Close the radiator drain petcock hand tight. Using a funnel, slowly pour the specified coolant mixture into the radiator until full. Fill the overflow reservoir to the cold fill line. Start the engine and allow it to reach operating temperature with the radiator cap off. Add coolant as the level drops during bleeding. Squeeze the upper radiator hose to help purge air. When the thermostat opens (upper hose becomes hot), top off the radiator and install the radiator cap. Allow the engine to run for 5 more minutes, then shut off and allow to cool.
    ⚠The cooling system will build pressure as it heats. Keep hands and face away from the radiator opening when the engine is running.

Reassembly

1. Reconnect negative battery cable
2. Reinstall engine cover if equipped
3. Remove all tools and drain pans from under vehicle
4. After cooling, check coolant level again and top off overflow reservoir to cold fill line as needed

Verification

• With engine cold, verify coolant level is at the top of the radiator and overflow reservoir is at cold fill line
• Start the engine and visually inspect all hose connections, transmission cooler lines, and drain petcock for leaks
• Allow engine to reach full operating temperature and verify cooling fan engages properly
• Check for leaks again at operating temperature, especially around hose connections and transmission cooler line fittings
• Verify heater produces hot air inside the cabin, confirming proper coolant circulation
• Monitor temperature gauge during test drive to ensure engine maintains normal operating temperature
• After test drive and cool-down, recheck coolant level and top off if necessary
• If equipped with automatic transmission, check transmission fluid level after radiator replacement and top off as needed

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