Initial Inspection and Diagnostic Overview
INSPECTION AND VERIFICATION1. Verify the vehicle owner's original concern by operating the engine cooling system to duplicate the concern.
Mechanical Or Electrical Concerns:
2. Inspect to determine if one of the Mechanical Or Electrical Concerns apply.
Rotunda Radiator/Heater Core Pressure Tester:
3. System leakage points can be determined using Rotunda Heater Core Pressure Tester as follows:
a. Turn the engine OFF.
WARNING: Never remove the cooling system cap under any conditions while the engine is operating. Failure to follow these instructions could result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the cooling system, or reservoir, use extreme care when removing the cap from a hot cooling system or reservoir. Wait until the engine has cooled, then wrap a thick cloth around the pressure cap and turn it slowly until the pressure begins to release. Step back while the pressure is released from the cooling system. When certain all the pressure has been released, (still with a cloth) turn and remove cap.
NOTE: If the coolant is to be replaced, the remainder of this procedure may be omitted.
b. Check coolant for dirty or rusty appearance. Dirty or rusty coolant requires replacement to protect the cooling system from corrosion damage. Replace the coolant.
NOTE: If coolant condition is satisfactory, check coolant concentration for proper protection level. Use a Rotunda Battery and Anti-Freeze Tester 021-00046 or equivalent, or a Hydrometer for testing. Maintain a protection level of at least -30° C (-20° F) to preserve anti-rust corrosion protection and ensure proper engine operating temperature. If concentration level is low, partially drain the cooling system by opening the radiator drain cock or by partially removing the lower radiator hose, secure the radiator drain cock or hose clamp and add 100 percent concentration of Premium Cooling System Fluid E2FZ-19549-AA (ESE-M97B44-A and ESE-M97B043-A) or equivalent to obtain the recommended protection level. Wet the rubber sealing surface of the radiator cap before installing the radiator cap tightly on radiator.
CAUTION: Use only a permanent-type coolant such as Premium Cooling System Fluid E2FZ-19549-AA (ESE-M97B44-A and ESE-M97B43-A) (in Canada, Motorcraft CXC-8-B) or equivalent.
c. Check coolant to the proper level.
b. Remove the cooling system radiator cap from the radiator to relieve pressure in cooling system. Reinstall radiator cap. Remove engine coolant system fill plug located on top of engine crossover tube.
d. Install the adapter fitting from Rotunda Radiator/Heater core Pressure Tester 021-00012 and Rotunda Pressure Tester Adapter 021-00066 or equivalent (male thread on one end and a hose connector on the other end to accommodate the tester hose) tightly into the engine crossover tube in place of the fill plug.
e. Disconnect the radiator overflow hose from the reservoir. Install a separate hose, making sure hose is firmly installed on the reservoir overflow nipple and is in good condition. Insert the free end of the radiator overflow hose into a container of water.
f. Attach the pressure pump and gauge to the adapter fitting and pressurize the cooling system to the cap lower limit.
NOTE: No bubbles should appear in the water container when the system is pressurized to the lower limit. If the system is satisfactory at the lower limit, gradually increase the system pressure until a slight stream of bubbles appears in the water container. This is the upper limit of the radiator cap.
g. Replace any radiator cap that exceeds the specified upper limit pressure without discharging bubbles.
h. If the pressure cap does not hold pressure, remove and wash the cap in clean water to dislodge all foreign particles from the gaskets. Check the sealing surface in the reservoir filler neck.
NOTE: Small amount of "weeping" from the water pump blend hole is normal.
i. Pressurize the cooling system as outlined in Step f (using a pressure cap that operates within the specified upper and lower pressure limits) and observe the gauge reading for approximately two minutes. Pressure should not drop during this time.
NOTE: If the pressure drops, check for leaks at the engine to heater core hoses, engine-to-radiator hoses, water valve hose (if applicable), thermostat housing gasket, radiator and heater core, etc. Also check engine if a leak cannot be located in cooling system. Any leaks which are found must be corrected and system rechecked.
j. If the system holds pressure, proceed to Step k.
k. Release system pressure by loosening the pressure cap and remove the adapter. Check coolant level and fill as necessary with correct coolant mixture and install fill plug on coolant crossover tube.
NOTE: If the concern remains after the inspection and pressure test, determine condition and refer to the Symptom Chart. Symptom Related Diagnostic Procedures