Perform a pressure test on the cooling system to identify leaks in hoses, radiator, water pump, thermostat housing, and other cooling components.

Warnings

Tools required

Parts

• Radiator cap (if defective) × 1 — Mopar 68241094AA or equivalent

Fluids

• Mopar OAT Coolant (Purple) — 1 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. Open hood and secure in raised position
4. Visually inspect cooling system for obvious leaks, damaged hoses, or wetness before testing
5. Place drain pan under radiator drain plug in case coolant needs to be drained

Procedure

1. 1

   Check coolant level and condition
   Remove the radiator cap slowly by turning counterclockwise. Check that coolant level is at the top of the radiator when cold. Inspect coolant color (should be purple/pink) and check for contamination, oil, or debris. Top off with Mopar OAT coolant if needed.
2. 2

   Inspect radiator cap
   Examine the radiator cap for damaged sealing surfaces, worn rubber gasket, or corroded spring. Check the pressure rating stamped on the cap (should be 16 PSI for this application). Replace cap if any damage is evident as a faulty cap can cause false test results.
3. 3

   Install pressure tester adapter
   Select the correct adapter from the pressure tester kit that fits the radiator filler neck on the 2014 Ram 2500. Thread or clamp the adapter securely onto the radiator filler neck, ensuring a tight seal. Verify the adapter is seated properly to prevent air leaks during testing.
4. 4

   Attach pressure tester
   Connect the pressure tester to the installed adapter. Ensure all connections are tight and the tester gauge reads zero before applying pressure. Familiarize yourself with the pump mechanism and pressure release valve on your specific tester.
5. 5

   Pressurize the cooling system
   Slowly pump the pressure tester to bring the system up to 16 PSI (the rating of the radiator cap). Do not exceed this pressure. Monitor the gauge carefully and stop pumping once target pressure is reached. The system should hold this pressure if there are no leaks.
6. 6

   Monitor pressure gauge
   Observe the pressure gauge for 10-15 minutes. A properly sealed system should maintain pressure with minimal drop (less than 2 PSI over 15 minutes is acceptable). A rapid pressure drop indicates a significant leak. Note the rate of pressure loss for diagnosis.
7. 7

   Inspect external components
   While system is pressurized, visually inspect all accessible cooling system components: radiator tanks and core, upper and lower radiator hoses, heater hoses, thermostat housing, water pump weep hole (located on bottom of pump), EGR cooler connections, charge air cooler connections, and all hose clamps. Look for active leaking, seepage, or wetness.
8. 8

   Check hard-to-see areas
   Use flashlight and inspection mirror to examine areas behind the engine: back of water pump, rear heater hose connections, cylinder head to block sealing surfaces, and underneath the engine for drips. On the 6.7L Cummins, pay special attention to the EGR cooler and its connections as these are common leak points.
9. 9

   Inspect heater core circuit
   Check inside the cab for signs of coolant smell or wetness on the passenger side floor. With system pressurized, have an assistant check for dripping under the dash. Heater core leaks may only be visible with the system under pressure.
10. 10

    Check for combustion gas intrusion (optional)
    If pressure increases beyond the initial 16 PSI while monitoring, this may indicate combustion gases entering the cooling system from a head gasket leak. This is rare but should be noted. If suspected, further testing with a combustion gas detector is recommended.
11. 11

    Release pressure and remove tester
    Use the pressure release valve on the tester to slowly depressurize the cooling system. Once gauge reads zero, disconnect the pressure tester from the adapter, then remove the adapter from the radiator filler neck. Wipe any spilled coolant from the area.
12. 12

    Document findings
    Record all leak locations found, rate of pressure loss, and component condition. If no leaks were found but customer reported overheating, consider testing radiator cap separately with a cap tester, or investigate other causes such as air pockets, thermostat failure, or restricted coolant flow.

Reassembly

1. Reinstall radiator cap securely, turning clockwise until it stops
2. Top off coolant overflow reservoir to COLD FULL mark if needed
3. Wipe down any coolant spills from radiator and engine surfaces
4. If leaks were found and repaired, retest the system following the same procedure

Verification

• System should hold 16 PSI for 15 minutes with no more than 2 PSI pressure drop
• No visible coolant leaks, seepage, or wetness at any component
• Radiator cap seats properly and pressure tester adapter sealed without leaks
• If system failed test, all leak sources should be identified and documented for repair
• After any repairs, run engine to operating temperature and retest when cool to verify repair success

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