POA Valve Removal and Bench Testing

[SavageC20]

I am planning on getting my factory A/C system working and am trying to figure out how to test the POA valve to see if it still works. I have been browsing the forums but have not found a thread w/pics showing how to test it and recalibrate it for use with r134. Also, I am having trouble removing the POA valve from the existing lines. Any tips? I don't want to twist any of the aluminum lines and break them.

[Jcfcamaro]

Following.

[tj1970cst]

Use a back up wrench, or a wrench on each side of the fitting. Maybe soak with penetrating oil overnight. R-12 vehicles aren't as bad at seizing fittings since they used mineral oil. Cars with pag can corrode fittings.

[Daaaanz67]

Subbed. Geez think I have read somewhere here about POA testing and calibration. Maybe it was on a chevelle forum. Calibration was turn center screw out 1/2 turn. Dang now you got me looking also.

[SavageC20]

Yeah I have seen many threads talking about testing and re-calibrating the POA but I couldn't find any about how to actually do it.

[tdangle]

It was actually pretty easy. I have the info, but I'm at work right now. Let me see if I can dig it up and post later this evening

[randy500]

Pressurize the poa inlet with low pressure air, 50psi or so.
It’s easier to pressurize it attached to the evaporator.
Hook up low pressure ac gauge to poa valve
Inside the poa outlet is a 11/32 nut if I remember the size correctly
Adjust the nut to obtain pressure you want, think 27.5 for 134a and 30.5 for r12

You can check for the correct pressure using your refrigerant temperature pressure chart, adjust to just at or above 32 degrees which gives max cooling without freezing up the evaporator.

When first pressurizing the poa you will usually hear a pop along with pressure rise above the set point, this is normal. After the pop the valve will regulate to pressure set point

[SavageC20]

Originally Posted by randy500

Pressurize the poa inlet with low pressure air, 50psi or so.
It’s easier to pressurize it attached to the evaporator.
Hook up low pressure ac gauge to poa valve
Inside the poa outlet is a 11/32 nut if I remember the size correctly
Adjust the nut to obtain pressure you want, think 27.5 for 134a and 30.5 for r12

You can check for the correct pressure using your refrigerant temperature pressure chart, adjust to just at or above 32 degrees which gives max cooling without freezing up the evaporator.

When first pressurizing the poa you will usually hear a pop along with pressure rise above the set point, this is normal. After the pop the valve will regulate to pressure set point

I’ll give it a shot thank you.