Diagnostic procedure
Mazda 6 Service Manual: Radiator cap
Warning
Never remove the radiator cap while the engine is running, or when
the engine and radiator are hot. Scalding coolant and steam may shoot out
and cause serious injury. It may also damage the engine and cooling system.
Turn off the engine and wait until it is cool. Even then, be ve ...
Mazda 6 Service Manual: Expansion valve removal/installation
1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. (See RECOVERY.) (See CHARGING.)
Caution
If moisture or foreign material enters the refrigeration cycle,
cooling ability will be lowered and abnormal noise will occur. Always
immediately plug open fitt ...