Cooling System Inspection

Special Tools:

WARNING: To avoid personal injury, do not unscrew the coolant pressure relief cap while the engine is operating or hot. The coolant system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly.

CAUTION: Check the coolant level, engine oil and transmission fluid, top off the coolant if needed, if there is engine coolant in the engine oil or transmission fluid the cause must he corrected and oil/fluid changed or major component damage may occur.

1. Inspect the coolant color:
^ If Premium Engine Coolant E2FZ-19549-AA or equivalent meeting Ford specification ESE-M97B44-A has a clear, light green or blue color, this indicates higher water content than necessary.
^ Dark brown could indicate unauthorized stop leak may have been used. Use Cooling System Stopleak Powder E6AZ-19558-A or equivalent meeting Ford specification ESE-M99B170-A only.
^ A light or reddish brown color indicates that rust may he present in the cooling system. Flush the system and refill with the correct mixture of water and Premium Engine Coolant.
^ An iridescent sheen on top of the coolant could indicate a trace of oil is entering the system.
^ A milky brown color may indicate that either engine oil or transmission fluid is entering the cooling system. If transmission fluid is suspected the cause may he a leaky radiator. Pressure test the cooling system. If engine oil is suspected, the cause of the leak may be internal to the engine.

2. If the engine coolant appearance is good, test the engine coolant range with the battery and antifreeze tester:
^ Maximum range is 60/40.
^ Minimum range is 40/60.

3. Adjust coolant range and level if necessary:
^ If the engine cooling fluid is low, add specified coolant mixture only.
^ If the engine coolant fluid tests weak, add straight engine coolant until the readings are within acceptable levels.
^ If the engine coolant tests strong, remove some of the engine coolant and add water until readings are within acceptable levels.