Cooling System Inspection

Special Tools:

1. WARNING: Never remove the radiator 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 radiator, use extreme care when removing the radiator cap from a hot radiator. 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 it is certain all the pressure has been released, press down on the cap (still with a cloth), turn and remove.

Note: Check the coolant in the radiator coolant recovery reservoir and radiator, if vehicle has not been allowed to reach normal operating temperature. This will make sure sufficient coolant exchange has occurred.

Allow the engine to cool and remove the radiator cap.
2. Inspect the coolant in both the radiator and the radiator coolant recovery reservoir for coolant color:
- Clear light green or blue indicates higher water content than necessary.
- Dark brown indicates possible use of unauthorized Stop Leak. Use Cooling System Stop Leak Powder E6AZ-19558-A or equivalent meeting Ford specification ESE-M99B170-A only.
- A light or reddish brown color indicates rust in the cooling system. Flush the system and refill with the correct mixture of water and Premium Engine Coolant E2FZ-19549-AA (in Canada, Motorcraft CXC-8-B, in Oregon, F5FZ-19549-CC) or equivalent meeting Ford specification ESE-M97B44-A.
- An iridescent sheen on top of the coolant indicates a trace of oil is entering the cooling system.
- A milky brown color indicates that oil is entering the cooling system.
- A reddish milky appearance indicates transmission fluid is entering the system.

3. CAUTION: If there is coolant in the engine oil, the cause must be corrected and the oil changed or engine damage may occur.

The causes of the leak might be:
- a blown head gasket.
- a cracked or warped cylinder head.
- a crack in the engine oil gallery and the cooling passageways.
4. The causes of other leaks might be:
- a leaky radiator.
- a leaky transmission fluid cooler.
Drain the fluids and repair or install new fluids as necessary. Add the correct mixture of water and Premium Engine Coolant E2FZ-19549-AA (in Canada, Motorcraft CXC-8-B, in Oregon, F5FZ-19549-CC) or equivalent meeting Ford specification ESE-M97B44-AA.
5. If the coolant appearance is OK, test the coolant range with the Rotunda Battery and Antifreeze Tester:
- Maximum range is 60/40.
- Minimum range is 45/55.
6. Coolant system conditions:
- If the cooling system is low, top off only with a premixed solution.
- If the coolant mixture is weak, add straight coolant until the readings are within acceptable levels.
- If the coolant mixture is strong, remove some coolant and add water until the readings are within acceptable levels.