Automotive Air Conditioning Information Forum

Hi, new to the forum here.
I'm looking for help in resurrecting an old system in a 1965 Mk10 Jaguar. The Delenair system is complete, consisting of a York style compressor, dual condensors and drier under the hood, the rest of the hardware trunk mounted and blowing air into the rear parcel shelf.

The compressor clutch is non-operative. There was no refrigerant in the system, but upon hooking my vacuum pump up, I pulled 30mm Hg vacuum which held for 48 hours, so the components might be tight. My idea is to replace the compressor with a "new" (given to me quite few years ago) Sanden SD505 that I have on the shelf, replace the drier, and try to charge it with R134a.
Questions:
Is this a good idea?
the hoses are long (up to 14 feet) - can I get away without replacing them?
Will I have to replace the expansion valve for R134a?
What kind of service valves do I need for the compressor? It's got S and D threaded ports and two separate Schrader valves on the body of the compressor. Are all the 505s compatible with R134a? I don't know when it was made.
I appreciate any help you can offer.
Ron

Those older hoses are not the "barrier" hoses that the R134A will need. Molecules of R134A are smaller than those of R12 and the 134A will leak out. The R12 compressor oil is also not compatible with the 134A. You will need a Schrader valve "port" kit for the 134A and for best operation, the 134A needs a modern parallel flow condenser to shed heat.

Rick

Thanks for the reply.
No personal experience, but I have read that old hoses are impregnated with oil and, assuming they are otherwise sound, can work as a barrier for 134a - any opinion about that? There is about 35 feet of hose in this car! As to the condensers, you mention best practice, but that implies that if my goals aren't too ambitious, the ones I have may suffice? I live in the Pacific Northwest, so a/c needs aren't huge. The primary condenser is long and narrow and might be hard to find, but I could probably find a stock unit for the secondary mounted in front of the radiator.

I'm thinking that if there is a reasonable chance for success on the old components, the only real risk is a little r-134a.

Anyone have an opinion about the expansion valve?

505 model compressor is pretty small. If you have a full-size York. The adapter plate and larger model compressor would be advised.

In addition to the SD505 being rather small displacement-wise, I believe some were set up for R-12 with mineral oil and some for R-134a with PAG oil. Check the label to see which one you have.

Over and above the compressor, if you want to convert it to R-134a, you'll have to flush out every component and replace some parts outright, as pointed out earlier, to get rid of all the old mineral oil. There's a tutorial under "Automotive Air Conditioning Procedures, Tips and FAQ" that discusses the procedure in detail.

On the other hand, if you can source some R-12, you could just keep it R-12. The system was originally designed for R-12 and will work best with it. You could then keep the old condensers and flush them well since they're the old-style serpentine type, and the original compressor apparently hasn't sent any metallic or other debris downstream.

If it's clean, I would re-use the original TXV because I doubt that you can find an OEM replacement for a 55-year-old car. In my experience, aftermarket replacements sometimes act up after the fact. And you don't want to have to take it all apart a second time to re-install the original TXV, especially if you keep it R-12, which is very costly today.

Pretty tough to find the R-12, I think, but I'll have a look. I would definitely want to be sure the system was absolutely tight before putting any of that in. Could I just use compressed air to check?

Yeah, I see that shop air is a problem. If I were to go R-12, I might have to get a pro involved. No dedicated AC shops in my neck of the woods.

Just buy a fresh York, and put it back together right.

That SD505 is a tiny unit. 90 cc/rev ? maybe less. The York is 210 cc/rev. See the problem?

I believe you are right. I was chatting with a friend who is a retired airplane mechanic. When they switched the fleet of planes over to r134a, all they did was to change the compressors and driers, and recharge the system. He said they all worked and continued to do so for 20 years. I'm sure the advice here is best practice, but I'm going to give simple a try. Worst scenario is that it doesn't work and I start over.
Thanks.

I have had 100% success on Class 8 trucks keeping the R-12 non barrier hoses. Recommend you eliminate the Delenair TXV inlet screen.