Molecule size of R134A is smaller than R12 so it has a tendency to leak out where R12 might be contained. So older hoses designed for R12 might not be as effective to properly contain the R134A, add breakdown of integrity of an older hose and you might see reduced capability of containing the R134A which is why A/C specialists would probably recommend new hoses for conversion to R134A from R12.
R134A in an R12 designed system will need recharging sooner, but the system will probably still work.
A/C Compressor & Condenser Replacement
Did I miss the part where we flush the system to remove accumulated dirt and miscellaneous compressor debris from the system? It seems that should be done with the expansion valve removal to eliminate that restriction. Does anyone have a writeup this comprehensive on that phase? Great post, especially the photography. I have done this job before and still find comfort in it before my current project. Newby here, owner of maybe 18 since 1986.
I would second that request!Z28DZ wrote: Tue May 06, 2025 6:00 am Did I miss the part where we flush the system to remove accumulated dirt and miscellaneous compressor debris from the system? It seems that should be done with the expansion valve removal to eliminate that restriction. Does anyone have a writeup this comprehensive on that phase? Great post, especially the photography. I have done this job before and still find comfort in it before my current project. Newby here, owner of maybe 18 since 1986.
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Tom
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I didn't truly flush the system. I changed the compressor and condenser and the system never blew up or anything -- just did it all to make the change to r134a. I did a mini flush with the ac pro stuff, but my heart wasn't in it so I didn't put it in the guide -- good point though.
It's been hot lately here, so I ran the a/c this week and am happy to say it's still blowing ice-cold. I didn't measure the temps, but with an 80+ ambient, I could get the cabin uncomfortably cold. Since it can maintain a full charge over the winter, I'm proclaiming the eBay condenser a success.
It's been hot lately here, so I ran the a/c this week and am happy to say it's still blowing ice-cold. I didn't measure the temps, but with an 80+ ambient, I could get the cabin uncomfortably cold. Since it can maintain a full charge over the winter, I'm proclaiming the eBay condenser a success.
I’m tackling the AC this weekend and plan to attempt to flush and would like a guide as well but I’ve been unable to find one especially for the earlier cars. The condenser lines are a little difficult to get to, but the evaporator lines and expansion valve will be the real PITA.
You will learn to despise Prestite tape. LOL...c5_pilot wrote: Thu May 22, 2025 2:36 pm I’m tackling the AC this weekend and plan to attempt to flush and would like a guide as well but I’ve been unable to find one especially for the earlier cars. The condenser lines are a little difficult to get to, but the evaporator lines and expansion valve will be the real PITA.
You'll use that before you use Prestite! LOL... or WANT to... it's just asphalt in tape form, literally. Getting all that old stuff out was the most annoying part of replacing the expansion valve.
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samaritrey
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Great guide I wish I had found it before I did my AC refresh on my 951!
I bought a roll of rubber adhesive strips 2 inch wide by 1/8 inch thick to wrap around the Drier and it worked great.
Center vent temp of 39F with 27oz of R134. 85F outside with about 243% Humidity so it was feeling nice inside even with my Saratoga roof.
Sadly, the weld broke on the condenser holding the metal line to the assembly when I did the orings.
Will have to replace it next time the system needs work.
I bought a roll of rubber adhesive strips 2 inch wide by 1/8 inch thick to wrap around the Drier and it worked great.
Center vent temp of 39F with 27oz of R134. 85F outside with about 243% Humidity so it was feeling nice inside even with my Saratoga roof.
Sadly, the weld broke on the condenser holding the metal line to the assembly when I did the orings.
Will have to replace it next time the system needs work.