Have a 2007 uplander with 70k miles. The air conditioner only works for a short time after a charge. I can here a hiss from the vent when the a/c is on, and will continue for a short time after I shut the a/c off. i assume it is a leak in the evaporater. How hard is it to change? does the dash have to be removed? Chance it could be something else???

 

I have the same issue with my 06 if anyone is in the know please let us in on it.