Which is the low pressure ac switch ? - ZR-1 Net Registry Forums

ZWILD1 · 07-31-2022

I was wanting to add freon to the system . I'm being lazy not using my FSM . Which one is the low pressure switch ?

402Z · 07-31-2022

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

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

Why don't you find where the leak is coming from so you don't have to keep filling it?

ZWILD1 · 08-01-2022

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

Fluorescent dye added to the system may find the leak better than a sniffer.

WARP TEN · 08-07-2022

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

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

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

Quote:

Originally Posted by ZWILD1

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

07-31-2022	#2
402Z Join Date: Sep 2021 Location: Florida Posts: 29	Re: Which is the low pressure ac switch ? If you want to add Freon, you?ll add it on the ac low pressure service port which is located on the accumulator.

07-31-2022	#3
ZWILD1 Join Date: Aug 2004 Location: Spring Grove ,Pa. Posts: 258	Re: Which is the low pressure ac switch ? 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 . __________________ 91 Turquoise Metallic Haibeck 525 #0134

08-01-2022	#4
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 220	Re: Which is the low pressure ac switch ? Why don't you find where the leak is coming from so you don't have to keep filling it?

08-01-2022	#5
ZWILD1 Join Date: Aug 2004 Location: Spring Grove ,Pa. Posts: 258	Re: Which is the low pressure ac switch ? 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 . __________________ 91 Turquoise Metallic Haibeck 525 #0134

08-05-2022	#6
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 220	Re: Which is the low pressure ac switch ? Fluorescent dye added to the system may find the leak better than a sniffer.

08-07-2022	#7
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,141	Re: Which is the low pressure ac switch ? 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 __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough"