AC issues (931 still running R12)
08-31-2019, 03:09 PM
#1
Rennlist Member
Thread Starter
AC issues (931 still running R12)
So my AC gradually stopped cooling. I took a closer look under the hood, and a PO has disconnected the freon pressure (I assume?) switch and installed a jumper...my guess is that switch went bad so rather than replace it and evacuate the system, he just bypassed it. So now there's no safety cutoff, but whatever.
I have some R12, so I went to fill it. With the AC not running so just from can pressure, low pressure fill valve open, I got up to 60 psi on the low gauge. I turned on the AC and the low pressure crept up to 90 psi while the high gauge read zero. That's not right. I have a leak detector, it saw nothing in the engine bay, but inside the cabin it was triggered. So I shut everything down to regroup.
Freon leaking into the cabin tells me there's a likely evaporator failure, or at least compromised o-rings in that area. I'm not really sure what to make of the high low pressure reading and the zero high pressure reading, however. I haven't seen that. Any thoughts?
UPDATE: Just read a thread on Pelican about someone who had a PO do a R134a conversion and put the high and low side adapters on the wrong side. Now...mine is R12 so its easy to attach to the wrong side, but I THOUGHT from reading I had done it right. Both ports on on my compressor, and there is an "S" with a dot near one which I understood to be "Suction" for the low side. However that's actually the thinner line coming off the compressor. Isn't the thinner line actually the HIGH side?
If I've hosed this up by charging through the high side I'm going to be pissed, although I thought that would blow the can up, in which case I should thank my lucky stars. In either case, I don't know why else I would be getting those readings...
I have some R12, so I went to fill it. With the AC not running so just from can pressure, low pressure fill valve open, I got up to 60 psi on the low gauge. I turned on the AC and the low pressure crept up to 90 psi while the high gauge read zero. That's not right. I have a leak detector, it saw nothing in the engine bay, but inside the cabin it was triggered. So I shut everything down to regroup.
Freon leaking into the cabin tells me there's a likely evaporator failure, or at least compromised o-rings in that area. I'm not really sure what to make of the high low pressure reading and the zero high pressure reading, however. I haven't seen that. Any thoughts?
UPDATE: Just read a thread on Pelican about someone who had a PO do a R134a conversion and put the high and low side adapters on the wrong side. Now...mine is R12 so its easy to attach to the wrong side, but I THOUGHT from reading I had done it right. Both ports on on my compressor, and there is an "S" with a dot near one which I understood to be "Suction" for the low side. However that's actually the thinner line coming off the compressor. Isn't the thinner line actually the HIGH side?
If I've hosed this up by charging through the high side I'm going to be pissed, although I thought that would blow the can up, in which case I should thank my lucky stars. In either case, I don't know why else I would be getting those readings...
08-31-2019, 05:22 PM
#2
Rennlist Member
Thread Starter
Ugh...well regardless of the markings, it seems I had the fittings reversed. With the gauges swapped around, I see more normal pressures indicative of very low freon. Unfortunately, adding more seems to be causing leakage into the cabin. Not really the result I was hoping for...