Start the engine and let it idle.
Turn on the air conditioning system. Set the fan switch to position 3 of the recirculation mode.
Observe the sight glass "arrow" on the refrigerant manifold: for about 10 seconds after turning on the air conditioning compressor, the sight glass should show refrigerant flowing without bubbles. If this is not the case, the system does not have enough refrigerant and cannot operate at full capacity.
If no bubbles are detected after turning on the air conditioning system, then there is very little refrigerant in the system or none at all. In this case, turn off the air conditioning system immediately, otherwise the compressor of the air conditioning system may be seriously damaged.
Caution: Do not open the air conditioning system. If refrigerant comes into contact with your skin, it may cause frostbite.
If necessary, top up the air conditioning system with refrigerant at a service station.
For details, please visit the website [FORDBOOK]