What do POA valves do?

[@michaelcollins1899]

I have a 72 chevelle, sat 20 yrs ac worked perfect b4. Just finishing up an 8 yr resto and got to the ac this week. I put new oil in compressor, changed drier, changed xpansion valve. Put in new r12 til it was slightly lower than ambient temp. Started car and ac came on. Ho side read 100(much too low. Lo side read 35 which I thought was pretty decent. I immediately noticed from poa all way back to compressor was solid frost. Xpansion valve was cold and sweating, but coming out of evaporator, suction line was just ambient in thos 6 inches then, immediately at pop was heavy frost and flex hose to compressor was very cold, and last 6 inches of aluminum pipe as it enters compressor was heavy frost again (not good) it's flooding compressor. I'm a 28 yr certified and licensed refrigeration tech in the large world of grocery, restaurants, commercial ice, etc, so I know my way around the ac stuff but automotive is definitely a different planet lol. Please advise. Also the 72 hi side port is at evaporator and not at compressor. So this 100 psi reading is after the travel all way thru condenser so really kinda not that low afterall. The hi side line at compressor was too hot to hold for long so I feel my compressor albeit 51 yrs old, is running good, but again, I'm not automotive and this poa thing is totally new to me Need advice.

[@LanceGrey]

Always do a new POA valve with any A/C repair.--Added assurance, & cheap Insurance. 🙂

[@alcc4964]

A well needed explanation for hot rod guys…thanks. Does the throttle body valve (65 chevelle) only need the top to rotate to adjust for 134a? If so, how much rotation(I’ve heard half a turn) clockwise or counter? Thanks

[@vascofurtado6706]

How do i get my poa valve to you. Thanks

[@agustinserrano6288]

Hello I have a 1962 impala factory AC and the POA valve has a lever for the pull cable why is this different than what i see in the video. Im also trying to get it going again with 134A what would i have to do to retrofit. Thank you

[@DouglasKlein-w4s]

On a ‘72 GM A Body, can 134 adapter added to a POA valve be removed once system is fully charged? Thank you!

[@hobbessoto9547]

With the POA replacement eliminator part, does the expansion valve get eliminated?

[@rickyglen0227]

I'm thinking by replacing R12 with 134a we would need to replace the expansion valve with an orifice valve, like an inline tube style. I'm researching this now.