Ford 2003 Mustang Workshop Manual page 1847

while the pressure is released from the cooling system.
When you are sure all the pressure has been released, turn
and remove the pressure relief cap (still with a cloth).
NOTE: Allow the engine to cool before checking the engine
coolant level.
Key in OFF position.
Visually check the engine coolant level at the degas bottle or
coolant expansion tank.
Is the engine coolant level within specification?
A2 CHECK THE PRESSURE RELIEF CAP
Carry out the Cap—3.8L or Cap—4.6L test. Go to Component
Tests in this section.
Is pressure relief cap/radiator cap OK?
A3 CHECK THE ENGINE COOLANT FOR INTERNAL LEAK
Key in OFF position.
Inspect the engine coolant in degas bottle/coolant expansion
tank for signs of transmission fluid or engine oil.
Is oil or transmission fluid evident in the coolant?
A4 CHECK THE ENGINE AND THE TRANSMISSION FOR
COOLANT
Remove the oil level dipstick from the engine and the
transmission.
Is coolant evident in the oil or transmission fluid?
A5 PRESSURE TEST THE ENGINE COOLING SYSTEM
Pressure test the engine cooling system. Go to Component
Tests in this section.
Does the engine cooling system leak?
Yes
GO to A3 .
No
INSTALL a new
pressure relief
cap/radiator cap. TEST
the system for normal
operation.
Yes
If engine oil is evident,
REFER to Section 303-
00 . If transmission fluid
is evident, REPAIR or
INSTALL a new radiator
as necessary.
No
GO to A4 .
Yes
If coolant is in engine,
REFER to Section 303-
00 . If coolant is in
transmission, REPAIR
or INSTALL a new
radiator as necessary.
To repair the automatic
transmission, REFER to
Section 307-01 .
No
GO to A5 .
Yes
REPAIR or install new
components. TEST the
system for normal
operation.
No
The cooling system is
operational. GO to
Symptom Chart .