Hi, all,

Last week, it was very hot here in New York city and I noticed my A/C did not produce cool air and the compressor clutch would kick in every 2 seconds. Yesterday, I got a recharge kit from the Autozone. After connected the gauge to low pressure end, the pressure was in the red zone when AC was off (at least 70, don't remember the exact number) and the pressure was below 20 when AC was on. After I put in about a can (12 oz) of Freon (134a), AC has worked great since. No more every 2 seconds cycling. Today, the pressure readings were 80 (Off) and 40 (on) with outside temp around 80F. I am very confused with the numbers showing in many postings. Can someone kindly help me out here? Thank you very much. My car is 95 850 non turbo.

Best,

P.

There is a little too much r134a in the system, but it should not do any harm. One factor not mentioned is the accuracy level of the refrigerant gauge. I bet it is on the safe side to prevent damage. In any case, you are probably OK, but it is wise to add r134a in small doses and check the pressure, after allowing to stabilize.

Hi, Mike and Marty,

Thanks a lot for your input.

Actually, I have spent past a couple of hours fiddling with the AC and ended up putting another can of Freon in and wasting "gallons" of gas. Yes, I tried to bleed a little but ended up bleeding to the point the AC cycling every 2 second again. No choice that I had to put another can in. For some reason, it took quite while to finish one can. This time, it read 25-30 when fan was on low to high (AC on) and 70 when AC was off (I guess I bled more than I put in). I measured the pressure of V70 with working AC. When the fan was on High, initial reading was 40 and gradually decreased to around 30 to 35, and it took more 20 minutes to get to the cycling point when the fas was on high. For my 850, when the fan was on the highest, the AC never got to the cycling point (the pressure never decreased below 25), though tonight is cool (around 70F) and it was freezing cold in the car. It did cycle when the fan was on the second highest (took a very long time). It cycled very frequent when the fan was on low. Why?

I will keep an eye on my AC and hope it is just age related leak and will let you know what it is going on.

Thanks again.

P.

You did the right thing, and saved yourself a bundle. Go to this site....

http://au.geocities.com/ozbrick850/aircon-keithP.html

It provides a nice 15 minutes of reading, and is about the best air conditioner description on the 'net.
If you scroll down to the very bottom of the "leak procedure" section, you'll find a sentence that says that normal operating pressure will be somewhere around a low of 20 psi, to a high of around 40 psi. It takes quite a bit more pressure to trigger the "high pressure" switch, and still more Freon to reach the point where you'd be flooding the expansion coil. All of these numbers are approximate, and are there are many variables. "Hamfisted" suggested that you may have overfilled a bit, and he is probably correct. If you bleed a little bit out (just to be on the safe side), that's cool (no pun intended), but you might want to check it again in a week or two. If the pressure is somewhat lower at that point, it's probably due to a slow leak somewhere in the system. Static pressure is almost meaningless... only the pressure reading when the A/C is running, and the cabin temperature has stabilized, is important. Put it on "recirculate" and "high" fan speed, then let it run for a few minutes holding the engine at a "high idle"... approximately 1500 RPM to get your most accurate pressure readings. Considering that the replacement of the evaporator coil (the most likely leak source) is a major task, both physically and financially, a couple cans of Freon a year is the better solution, at least for now. But hey, summer is almost over anyway...just a few more weeks.

Good luck

Marty
'96 855T

You put in a little too much freon, bleed some off until you get a low side reading of 25-35 psi with the compressor on. It will be fine.





Mike
'95 850T