Hello all,
The lo port on my compressor does nothing. I could not take a reading from it nor charge the system.
Is it possible that the port is bad and blocked. The hi port is OK. The sticker on under the hood says R-12, but the hi/lo ports are 134a type. The AC gives out cool air, not chill or cold. I can see bubble flowing thru in the glass window.
How much 134a will escape if I replace the lo port. If I want to verify the type of gas inside the system, which port I should take a reading so I can compare with the chart to see if it is r12 or r134a?
Is there time that someone put a new type of connector on the compressor but still use r12?
Last, how do I replace this lo port connector?
Thanks a lot,

Hello again,
I just check with my brother who is an original owner of the volvo I have now.
He says that the ac has never been repaired yet. So that means it is R-12, but I am still puzzled by the r-134a severvice ports on the compressor.
Also, the car was ordered directly from oversea and delivered in oct 1989. It has a electronic ERG valve which tells it is built for CA.
I am thinking of to bring to AC shop and have them evacuate, vacuum and filled with r-12 or r-134a.. basically, I let them tell me which direction to go.
Any info.. I appreciate much.

thanks,

Hi nguyenmman,

If you try replacing the lo port, all of the gas will escape.

And you cannot tell what type of gas is in the system by taking a pressure reading. All that you do know is that your undercharged by the appearance of bubbles in the sight glass, and cool air from the vents.

It's hard to tell exactly what the previous owner of the car did to the A/C. First, the R134 ports hi/low would suggest conversion to R134a. To be absolutely certain, there should be a blue sticker under the hood attesting to this fact. But your sticker says R12? Hmmm...confusing. You can't add R12 through R134 fittings.

Next, your low port may be blocked because the retro-installer may not have removed the old ports valve before installing the new fitting.

My humble advice would be to have the old gas evacuated by a professional, and then check the low port fitting. Then draw a vacuum on the system to test for leaks.

If all is well then recharge with the proper ester oil and R134a. Also, check to see if the receiver/drier has be changed. You can tell by a sticker on the side of the cylinder.

Best wishes,

Tony

Thank you very much for your advice.