Ford 2003 Mustang Workshop Manual page 1857

"COOLANT FILL LEVEL" marks and replace the pressure cap.
7. Select the maximum cool temperature setting.
8. Run the engine until it reaches operating temperature.
9. CAUTION: If the engine coolant temperature gauge does not move, the engine
coolant level in the engine is low and must be filled. Stop the engine, allow it to cool and
fill the cooling system.
Add the correct engine coolant mixture to the degas bottle until the coolant level is between the
"COOLANT FILL LEVEL" marks.
10. Repeat the two previous steps until the engine coolant mixture is between the "COOLANT FILL
LEVEL" marks on the degas bottle. Turn off the engine and allow it to cool.
11. Check the freeze protection of the engine coolant mixture with the Battery/Anti-freeze Tester
014-R1060 or equivalent. Adjust freezing point range if necessary.
Filling — Cobra
CAUTION: Vehicle cooling systems are filled with Motorcraft Premium Gold Engine
Coolant VC-7-A (in Oregon VC-7-B) or equivalent meeting Ford specification WSS-M97B51-A1
(yellow color). Always fill the cooling system with the same coolant that is present in the
system. Do not mix coolant types.
CAUTION: Engine coolant provides freeze protection, boil protection, cooling efficiency,
and corrosion protection to the engine and cooling components. In order to obtain these
protections, the engine coolant must be maintained at the correct concentration and fluid level
in the degas bottle.
When adding engine coolant, use a 50/50 mixture of engine coolant and deionized water.
To maintain the integrity of the coolant and the cooling system:
Add Motorcraft Premium Gold Engine Coolant VC-7-A (in Oregon VC-7-B) or equivalent
meeting Ford specification WSS-M97B51-A1 (yellow color). Use the same coolant that
was drained from the cooling system. Do not mix coolant types.
Do not add/mix orange-colored Motorcraft Speciality Orange Engine Coolant VC-2 or
equivalent meeting Ford specification WSS-M97B44-D. Mixing coolants may degrade the
coolant's corrosion protection.
Do not add alcohol, methanol, or brine, or any engine coolants mixed with alcohol or
methanol antifreeze. These can cause engine damage from overheating or freezing.
Do not mix with recycled coolant unless it meets the requirements of Ford specification
WSS-M97B51-A1. Not all coolant recycling processes meet these Ford specifications.
Use of such coolants can harm the engine and cooling system components.
NOTE: The addition of Motorcraft Cooling System Stop Leak Pellets, VC-6, darkens Motorcraft
Premium Gold Engine Coolant from yellow to golden tan.
1. Check all hose clamps for correct tightness. Make sure the radiator draincock is closed.
2. Place the heater temperature selector in maximum cool position.