[BIRDMAN]

1.Has it lost the gas again as there must be a leak to of lost it in the first place. Had my 2004 Sorento for 11 years and never needed re pressuring. If not used regularly seals dry out.
2. Is clutch engaging on compressor and driving pump when air con switched on. Often these sieze up

 

[BIRDMAN]

If you lift the hood with engine running and air con on you will see if the pulley is just being driven by the belt but not turning the pump. As for gas do as previous post, and get checked with an air con specialist who if leaked,will find the leaking cause.

 

[BIRDMAN]

The pulley will always be turning with engine running but clutch only engage to drive pump when air con switched on.