1998 volvo s70 air cond issue
 

I just put 2 cans freon in air conditioner. It blows cold air for a while then stops and blows warm air. Any suggestions on the problem?

Welcome to the Forum. It sounds like you have a major freon leak. Does the freon you put in have UV die in it? If so, check around the engine bay to see if you can find the leak.