Ford 2003 Mustang Workshop Manual page 1903

A1 CHECK THE INTERCOOLER COOLANT LEVEL
WARNING: Never remove the pressure relief 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, use extreme
care when removing the pressure relief cap from a hot degas
bottle. Wait until the engine has cooled, then wrap a thick cloth
around the pressure relief cap and turn it slowly one turn
(counterclockwise). Step back while the pressure is released
from the cooling system. When certain all the pressure has
been released, remove the pressure relief cap (still with a
cloth). NOTE: Allow the engine to cool before checking the engine
coolant level. The engine must be off to check the coolant.
Key in OFF position.
Visually check the intercooler coolant level at the degas bottle.
Is the coolant level within specification?
A2 CHECK THE DEGAS BOTTLE PRESSURE RELIEF CAP
WARNING: Never remove the pressure relief 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, use extreme
care when removing the pressure relief cap from a hot degas
bottle. Wait until the engine has cooled, then wrap a thick cloth
around the pressure relief cap and turn it slowly one turn
(counterclockwise). Step back while the pressure is released
from the cooling system. When certain all the pressure has
been released, remove the pressure relief cap (still with a
cloth).
Remove the pressure relief cap.
Inspect the pressure relief cap for foreign material between the
sealing gasket and the diaphragm.
Is the pressure relief cap OK?
A3 CHECK THE DEGAS BOTTLE
WARNING: Never remove the pressure relief 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, use extreme
care when removing the pressure relief cap from a hot degas
bottle. Wait until the engine has cooled, then wrap a thick cloth
around the pressure relief cap and turn it slowly one turn
(counterclockwise). Step back while the pressure is released
from the cooling system. When certain all the pressure has
been released, remove the pressure relief cap (still with a
cloth).
NOTE: The engine must be cool when coolant is added to the degas
bottle.
Add coolant to the degas bottle until fluid is between the coolant fill
level marks.
Does the degas bottle leak?
Component Tests
Test Step
Result / Action to
Take
Yes
GO to A2 .
No
REFILL the coolant
as necessary. GO
to A2 .
Yes
GO to A3 .
No
CLEAN or INSTALL
a new pressure
relief cap. TEST the
system for normal
operation.
Yes
INSTALL a new
degas bottle. TEST
the system for
normal operation.
No
CARRY OUT the
cooling system
pressure test.
REFER to the
Component Tests
in this section.
REPAIR as
necessary. TEST
the system for
normal operation.