View Full Version : Which is the low pressure ac switch ?
ZWILD1
07-31-2022, 09:50 AM
I was wanting to add freon to the system . I'm being lazy not using my FSM . Which one is the low pressure switch ?
If you want to add Freon, you?ll add it on the ac low pressure service port which is located on the accumulator.
ZWILD1
07-31-2022, 05:22 PM
Yes I got that part . I see other post on the Corvette Forum saying you need to clear the low freon code and then jump the low pressure switch to get the AC compressor to turn on . They say you can't fill the system if it doesn't come on. I know that when I had it filled the shop I went to had no trouble filling the system with 134A . After they filled it I disconnected the positive battery terminal for a minute and the AC started blowing cold . I also know that if you don't clear the 09 low freon code jumping the switch will not energize the compressor .
mlipmd
08-01-2022, 01:36 PM
Why don't you find where the leak is coming from so you don't have to keep filling it?
ZWILD1
08-01-2022, 06:08 PM
The shop I've been using to fill it said they would try and detect the leak this year . I like them because I make an appointment and they do it while waiting . The previous owner had Marc Haibeck replace the compressor and clutch . The following year it was low on freon. He took it back and Marc couldn't find the leak using a sniffer . Hopefully they can find it . Generally it last about 6 months . So you would think it should be detectable .
mlipmd
08-05-2022, 11:51 AM
Fluorescent dye added to the system may find the leak better than a sniffer.
WARP TEN
08-07-2022, 09:59 AM
I recall Marc saying that almost all A/C leaks are related to the Schrader valves, especially the hard-to-detect small ones. He has fashioned a screw on cap that tightly seals them and he says stops the leaks. If you haven't already, you might contact him and ask about that. --Bob
mlipmd
08-07-2022, 12:45 PM
I found my leak using dye and it was from the high pressure Schrader valve. When I put a drop of water onto it, you could actually see bubbles coming out. After I replaced it and refilled the system, all's good, ice cold AC, no more leaks.
What year is your car? And if it has it been converted from R12 to R134A, then the fill ports have been changed for the conversion, and you need to get the correct valve stem for the R134A port if one is leaking. High and low valves are different.
And the shop was able to put Freon in without the compressor running because they may use a high pressure pump and not an auto store spray can.
ZWILD1
08-08-2022, 06:12 PM
Marc did the conversion to 134 so it has the caps on the high pressure line and the receiver. Possible it could be leaking from the other side of the receiver. Hope it's not the evaporator core .
WARP TEN
08-09-2022, 11:19 AM
Marc did the conversion to 134 so it has the caps on the high pressure line and the receiver. Possible it could be leaking from the other side of the receiver. Hope it's not the evaporator core .
Yep that looks like the "cap" he uses. --Bob
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