Pressure Test

WARNING: NEVER REMOVE THE RADIATOR CAP UNDER ANY CONDITIONS WHILE THE ENGINE IS OPERATING OR WHEN THE COOLING SYSTEM IS HOT. FAILURE TO FOLLOW THESE INSTRUCTIONS COULD RESULT IN DAMAGE TO THE COOLING SYSTEM OR ENGINE OR PERSONAL INJURY. TO AVOID HAVING SCALDING HOT COOLANT OR STEAM BLOW OUT OF THE RADIATOR, USE EXTREME CARE WHEN REMOVING THE RADIATOR CAP. WAIT UNTIL THE ENGINE HAS COOLED, THEN WRAP A THICK CLOTH AROUND THE RADIATOR CAP AND TURN IT SLOWLY TO THE FIRST STOP, STEP BACK. WHILE THE PRESSURE IS RELEASED FROM THE COOLING SYSTEM. WHEN THE PRESSURE HAS BEEN RELEASED, PRESS DOWN ON THE RADIATOR CAP (STILL WITH A CLOTH), TURN AND REMOVE IT.

1. Shut off the engine.
2. Open hood and install protective fender covers.
3. When engine is cool, carefully remove radiator cap.
4. Disconnect battery ground cable.
5. Adjust radiator coolant level to 25 mm (1 inch) below filler neck before testing.
6. Disconnect the electrical connector from the water temperature indicator sender unit and remove the water temperature indicator sender unit from the engine.
7. Install the adapter fitting from the Rotunda Radiator/Heater Core Pressure Tester or equivalent (the adapter has a male thread on one end, and a hose connector on the other end to accommodate the tester hose).





8. Remove the radiator overflow hose from the overflow nipple. Install a separate hose firmly on the overflow nipple. Insert free end of hose into a container of water. Wipe sealing surfaces of filler neck and inspect for scratches, cracks, gouges, etc., that may prevent proper sealing. If seal surfaces are damaged in any way the radiator must be replaced.
9. Attach the pressure pump and gauge to the adapter fitting and pressurize the cooling system to 97 kPa (14 psi) (minimum test pressure).

No bubbles should appear in the water container when the system is pressurized to the minimum test pressure. Gradually increase the system pressure until a slight stream of bubbles appear in the water container. Do not exceed the maximum operating pressure specification of 124 kPa (18 psi).

Replace any radiator cap that exceeds the specified maximum operating pressure without discharging bubbles.

10. Remove and wash the radiator cap in clean water to dislodge all foreign particles from the gaskets if the radiator cap does not hold pressure. Check the sealing surface in the radiator filler neck.

Inspect the cam lock flanges on both sides of the filler neck for maximum cap engagement.

11. Pressurize the cooling system as described in Steps 7-9 (using a radiator cap that operates: within the specified minimum and maximum pressure limits) and observe the gauge reading for approximately two minutes. Pressure should be held between 97 and 124 kPa (14 and 18 psi) and should not drop during this time.

Results: If the system holds pressure, proceed to Step 12.

If the pressure drops, check for leaks at the engine-to-heater core hoses, engine-to-radiator hoses, bypass hose, water valve hose (if applicable), thermostat housing gasket, radiator and heater core, etc. Also refer to engine system checks if a leak cannot be located in the cooling system. Correct any leaks found and recheck the system.

12. Release the system pressure by loosening the radiator cap, then remove the adapter. Install the . water temperature indicator sender unit and check coolant level. Replenish as necessary with the correct coolant solution.
13. Check the radiator overflow hose for any obstructions which may block the flow of coolant either to or from the radiator coolant recovery reservoir.
14. Connect battery ground cable.

NOTE: When the battery voltage is removed from the powertrain control module (PCM), all learned values will be cleared and reset to predetermined values. When battery voltage is restored to the PCM, the vehicle may exhibit certain driveability concerns. It will be necessary to drive the vehicle to allow the PCM to relearn values for optimum driveability and performance.