POA valve adjustment 1972 Cutlass
September 8th, 2012, 03:30 PM
#1
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POA valve adjustment 1972 Cutlass
Anyone have pictures/diagrams/clips of how to adjust Frigidaire POA valve from 12 to 134a? I've seen talk of a locknut and screw adjustment but don't see it. Is it in the throat or one of the side ports? Sounds pretty straightforward if you know where to look.
Thanks in advance
Thanks in advance
September 8th, 2012, 08:12 PM
#2
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Location: Plano, TX
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It is in the evaporator side - the inlet to the POA valve. I think it is a 7/32 nut but depends on year. Some have a tiny locknut on them.
I just calibrated one for a friend and is pretty straightforward, as long as it is off the car. I took pictures so I can add them here if you think they would help.
BTW, welcome to the forum!
I just calibrated one for a friend and is pretty straightforward, as long as it is off the car. I took pictures so I can add them here if you think they would help.
BTW, welcome to the forum!
September 11th, 2012, 12:10 PM
#3
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Rob,
Thanks a lot for the info and for the welcome. I've been reading you guys for a while and have learned a lot - I appreciate the great sharing of knowledge. I've attached pictures of my valve (both ends to be sure). It doesn't look like what I've read described in terms of locknut and screw, but maybe I'm missing something. Anyway, thanks for any advice you can give.
Thanks a lot for the info and for the welcome. I've been reading you guys for a while and have learned a lot - I appreciate the great sharing of knowledge. I've attached pictures of my valve (both ends to be sure). It doesn't look like what I've read described in terms of locknut and screw, but maybe I'm missing something. Anyway, thanks for any advice you can give.
September 11th, 2012, 07:33 PM
#4
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Location: Plano, TX
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Looks like your valve does not have a locknut, just the adjustment nut.
Basically you will turn that nut 1/4 to 1/2 turn CCW.
For an accurate test, make up a fitting to where you can blow 60lbs of air into the inlet of the POAV and monitor the pressure at the low-side charging port on the POAV. I did one for a friend this way and it worked perfect. I used a scrap evaporator and connected a hose from my shop compressor to the expansion valve.
I turned the 60lbs of shop air on slowly, and the POAV kinda clicked when its regulation pressure is met. Air will come out the POAV outlet.
For R12, I got 32 PSI. I turned the nut in the outlet of the POAV) about 1/4 turn CCW and I got 27 PSI, an optimal value for R134. 1/8 of a turn is roughly 2 PSI if you cannot set it using pressure.
Here is the crude test setup:
Here is the pressure I dialed onto - 27psi:
Basically you will turn that nut 1/4 to 1/2 turn CCW.
For an accurate test, make up a fitting to where you can blow 60lbs of air into the inlet of the POAV and monitor the pressure at the low-side charging port on the POAV. I did one for a friend this way and it worked perfect. I used a scrap evaporator and connected a hose from my shop compressor to the expansion valve.
I turned the 60lbs of shop air on slowly, and the POAV kinda clicked when its regulation pressure is met. Air will come out the POAV outlet.
For R12, I got 32 PSI. I turned the nut in the outlet of the POAV) about 1/4 turn CCW and I got 27 PSI, an optimal value for R134. 1/8 of a turn is roughly 2 PSI if you cannot set it using pressure.
Here is the crude test setup:
Here is the pressure I dialed onto - 27psi:
Last edited by Lady72nRob71; June 22nd, 2014 at 04:23 PM. Reason: add pics!
September 12th, 2012, 09:38 AM
#6
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Join Date: Feb 2008
Location: Plano, TX
Posts: 11,798
Let me know how it goes.
Use an accurate A/C low pressure gauge to monitor the POAV release pressure.
If the reading fluctuates, or it sounds like a duck being choked, then the valve would need to be rebuilt or replaced.
I encourage folks visiting bone yards to grab these valves, as many will still test good. At a bone yard you might pay 10 apiece. A NOS valve can run up to 650! These are not being reproduced.
Use an accurate A/C low pressure gauge to monitor the POAV release pressure.
If the reading fluctuates, or it sounds like a duck being choked, then the valve would need to be rebuilt or replaced.
I encourage folks visiting bone yards to grab these valves, as many will still test good. At a bone yard you might pay 10 apiece. A NOS valve can run up to 650! These are not being reproduced.
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