So my a/c system was totally converted over to an R-134a system in 2004 by the previous owner. However, when I bought the truck, the a/c never blew cold and still doesn't. So I buy one of the large cans of refrigerant with the guage on it and check my low pressure side and it was low, so I added the proper amount till the guage said full, with the the car running and max a/c on...yada yada.
The compresor will kick on and cycle, but no cold air. I checked a few days later again and the system pressure was a little low. That told me I must have a leak somwhere. am I right? and would this cause the air to not blow cold? or is it a clogged oraface valve? idk... I need some help! Thanks!

 

It definitely sounds like you have a leak. How low was the pressure both times? Itd help alot if you had a set of guages and could check the high side too, especially to determine if theres a blockage somewhere. If it leaked down that fast its a pretty good leak. The upside to that is that its usually easy to find. Personally, Id suggest going ahead and investing in a good set of guages cuz theyll more than pay for themselves the first time you fix one of your vehicles systems yourself. And to fix this leak, youre gonna need to evacuate the system which will require them.

Systems that have been converted from R12 to R134a never cool as well as when it had R12 nor as good as an R134a system so even when its operating properly its probably not gonna be as cold as youd like and when its low its definitely not gonna keep ya very cool. Dont get me wrong, it will work pretty decent as long as its got a good charge but it sounds like you definitely need to fix a leak first...and Id hurry cuz its getting hot!

 

yea I've been meaning to invest in a set of guages, it would def. help. I did find last night the possible cause for the leak- On the high pressure side a metal fitting that goes into the condenser- like one of the metal return hoses had a little wetness around the threads. The pressure went from a proper "45" reading on the low side, down to around 30-35 or even a little lower when I checked it again. How much do ya think one of those little metal hoses is gonna cost me?

 

Im not sure exactly what kinda setup you have there but if its around one of the connections, which it usually is, you can usually fix it with new o-rings, theres no need to replace the whole hose assembly unless a crimped connection or the hose is leaking. But Id make sure thats the only leak first, which means youll need to check the other connections.