Sup3r52man

I have recently been experiencing an issue with my A/C System in my 94 Mustang GT. About a year ago the temperature of the A/C started going warm, so I checked the pressure and had the A/C recharged, blew cold, problem fixed so I thought. The car has been garage kept and not much driving has been done with it in the last year. The A/C Clutch cycles on for a few seconds and then off for about a minute and then tries to cycle back on. Besides low coolant and/or a leak, what are other possibilities that might need to be checked/replaced.

TwotoneVert

Thats about it. If the compressor is cycling on and off, the low pressure switch is working and so is the compressor. When they set and are not used, the o rings can dry out and leak coolant. Its always a good idea to run the a/c once a month to help prevent this. If you have the 134a, go to wal-mart or auto parts store and get some. You shouldnt need more than two 8oz cans.

mjr46

you' probably have a leak but to properly verify problem you need to hook a set of pressure gauges up and observe what the pressures are doing and at on the high and low side

Sup3r52man

What are the recommended pressure read-outs for each side, high and low?

Derf00

Depends on the specific system. 35-45 is about average for low-side and 200-220 is average for the highside. You could also have a blockage in which case the highside will not go up in pressure very fast when teh compressor kicks on. Also when the system is off and the car is turned off the high side and low side will not equalize easily. It normally takes about 20-30 minute but when there is a clog it may take hours. I'm guessing a leak though since the o-rings tend to shrink over time. Especially after long periods of non-use.

Sup3r52man

This might be a silly question, but depending on the pressure read-outs, when there is a leak, does that intail that all of the R134a will have leaked out and the A/C system could then possibly be worked on but someone not certified to do so. And is it recommened to have the o rings replaced?

Sup3r52man

So I ran a gauge on my low side port and with the car on and the A/C on max, it goes from the low green to the high yellow, and continues to cycle like this every few seconds. Any Ideas?

Arrid Extra Dry

i would knock out the back window and put a small window unit in it.
then get a personalized tag that says (RIDINCOOL)
but seriously like typed before up there, it sounds like you just have a leak.(or a weak compressor)
o-ring, line, condesnsor, or it could even be leaking out of the front of the compressor, which alot of pos auto zone rebuilt compressors do.(which might stop after you run it?)
if you replace everything on it, theres still a possibility that you will have a small leak.
if you buy a new compressor, buy a new one from a ford dealer, and not from auto zone.
i put 4 on mine from autozone before i got one that would work, and it sounds like a hung up pea thrasher. i would definatly put a new dryer, and orphus, blow the system out, replace all o-rings you can get too. suck it down to make sure it doesnt have any bad leaks, then put some leak detector in it , charge it up and take the window unit back to home depot . but i would keep the personlized tag.
when i first bought my big truck, the guy that had it before me, had a problem with compressors going out. He put 4 compressors on it, even all new lines, everything new. He took it too 2 or 3 shops and they couldnt figure it out. it kept building up too much pressure. one shop even put a pusher fan in front of the condensor. still had the same problem.
when i bought the truck, i took the condensor out, threw it in the garbage, put a new expantion valve,dryer, everything. But i took the inner cooler off, and the radiator was stopped up.
if its not flowing air through the condesnor right it wont cool.
but like posted above, if you dont drive it alot, start it up, turn the ac on and let it run for a while,and let everything circulate.

FrostByte

+1
If you need to keep refilling it or you can HEAR/find a leakthen have it looked @ by a certified tech (yes, I am certified). If you keep refilling it from the small cans you buy in a auto store then you are also adding oil to the system.The oil dosnt usually leak out & you end up overfilling system w/ oil which then acts as an insulator to the piping slowing heat transfer and or sending an oil slug to the compressor damaging it. The big 30lb tanks Iusedont have oil in them soyou just waste refrigerant.

shawnk007

Check for any airflow interuptions with your condenser. Make sure its getting good airflow and not all dirty.