Hello biotgers! My ac on the Sentra (225k miles) decided to call it quits this Sunday so now I have two temperatures...Hot and hotter. So naturally I figured it was low on refrigerant but I did some snooping around under the hood before adding any since now I have about 6 months or so to figure it out before the temps start creeping back up outside. First thing I checked was to make sure the compressor was kicking on...Check....Touch the high/low pressure lines to feel for a temperature difference....Nothing....Now bear in mind the car has not been cooling real good since we've had it for the past year or so. I assumed that's just how it was and lived with it. So I looked at the hoses first....High pressure hose looked fine, but, the low pressure hose had oil weeping (very very very slow/small leak) at the fitting where the rubber hose is crimped onto the metal line. So I have one of those ordered and on the way. So after spending all day searching the forums I have a few questions. First I'm not sure there is any 134a left in the system to be honest, but, if there is how could I check before popping off the hose? Maybe at the schrader valve? I'm not sure if a stop leak additive was ever used in this system so will I have to worry about that gunk hardening as soon as air gets to it when the lines off? Because I do not know about the stop leak should I look into running a solvent flush through there? Do I need to worry about adding any more pag oil in the line (haynes manual says nothing about adding oil when replacing hoses...They don't even mention replacing the hoses)? I'm going to put the system under vacuum for a bit after the hose is replaced before adding 134a back so if there is any of that stop leak/solvent will that cook it off? And finally I'm looking to add Arctic Freeze as it seems consensus that is supposed to be good on the posts I read. Would you guys recommend getting a can with the uv dye for easier ac leak diagnosis in the future?