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Old Chrysler A/C

Posted: Sat May 16, 2020 10:52 am
by grumpy old man
I have a 65 Chrysler presently sitting in my side yard. It is a limited use driver that belongs to a friend in Australia, she drives it anytime she is in the States. The likelihood of her needing it anytime soon is slim to none, so I am fixing all the little irritating things that always exist in a car of this vintage, (something to deal with my boredom at this time). I am presently putzing with the A/C. My A/C equipment is limited and hobby quality at best. The history of this unit is it will hold a charge for a few months. It held a partial vacuum over night and with can pressure my So So leak detector does not detect anything. When I was contracting we used spectroline in home and commercial units with a fair degree of success but I can find no information on using it in an automotive unit. Spectroline does in one place on its website state that it is applicable to automotive usage but no information on how much of which product. This is a last ditch effort, if it works great if not nothing lost. I have double wrenched and tightened all the flare connections so there is the possibility that I may have inadvertently fixed a small leak but wishful thinking never fixed anything.

Anyone have any information on using spectroline in an automotive application? I have researched every auto leak sealer sold and none of them list the sealant used or even if it is a polymer based product so am not willing to pump it in not knowing.

Re: Old Chrysler A/C

Posted: Sat May 16, 2020 3:53 pm
by Dougflas
This is an R12 system. You can try putting a shower cap on the compressor and let it sit. Then after a few hours, put a leak detector inside the shower cap. This system also uses an EPR valve so it is handy to have another low side gauge. I do have gaskets for that system. I would also advise you to replace all of the o rings and do not over tighten them. 55 year old system. Hoses are also suspect.

Re: Old Chrysler A/C

Posted: Sat May 16, 2020 4:50 pm
by bohica2xo
Definite NO on the sealer.

Put some dye in it, make sure there is enough oil in the compressor sump. Charge it & drive it a little every day for a week. Then use a UV light to find the leak.

Re: Old Chrysler A/C

Posted: Sat May 16, 2020 5:32 pm
by grumpy old man
Forgot to mention that it was converted to 134 before I ever saw it.

O rings? I have not broken down any hose connections but I remembered these as having flare connections. If they are o ring connections I will break them all down. Should I use the green o rings?

It does have a sight glass so the charge is not a problem and when charged it does cool surprisingly well on 134 so don't know what good a second low side gauge would do for the issue but thanks for the info.

Also the leak is such that there is no discernible oil residue, all the connections are powder dry but the dye is a good suggestion unless it is the evaporator.

As I did not do the 134 conversion I have no idea what it has in it for oil so I may suck it all out and replace it with known Pag oil with dye, how much oil does it need? Also where do I get the least expensive UV light as this could be the only time I will ever use it.

As for gaskets front and rear flange and sump? And how do I go about getting them if it seems necessary?

You guys are getting me into a lot more work than I had planned on but in reality what the h... else do I have to do.

Re: Old Chrysler A/C

Posted: Sun May 17, 2020 3:07 am
by Al9
grumpy old man wrote:so I may suck it all out and replace it with known Pag oil with dye

There's no such thing as "suck it all out". It's "flush it all out". You guess it, things have to come apart to be flushed.

grumpy old man wrote:You guys are getting me into a lot more work than I had planned on but in reality what the h... else do I have to do.

This is auto air conditioning. All is well while everything is working fine. Once it starts misbehaving, it's a nightmare to fix.

Re: Old Chrysler A/C

Posted: Sun May 17, 2020 9:52 am
by bohica2xo

While the '65 is mostly flared fittings, the OEM A/C cars have a pair of O ring fittings right at the firewall for the evaporator.

We are assuming this is OEM A/C - but in '65 lots of cars had dealer installed A/C. Presuming you still have the V2 pump on the car, the R12 shaft seals on those were not always happy when converted to 134a.

Is this a C body B body or an A body Mopar?

For a cheap blacklight go to Lowes or Home Depot. They have LED blacklight bulbs that will fit in your drop light. Cheap. Reliable. Bright.

Min oil is 6 ounces, max is 8 ounces. Dipstick drawings are on the internet. If you suck out the sump dry, put at least 6 ounces back in.

Re: Old Chrysler A/C

Posted: Sun May 17, 2020 12:17 pm
by grumpy old man
It is a Newport which I believe is a C body. It is a factory air, still has the airtemp sticker on the rear window, V2 compressor. That being said is there a shaft seal available that is 134 compatible. As long as I am going this far might as well go for the gusto. As memory serves the shaft seals were a carbon seal which required a three pronged tool to r&r the seal. Presumably I can find one of those on E bay.

I started breaking down the connections and so far they are all o ring connections, the discharge connection at the front of the compressor did not have an o ring in it which may explain a lot. So much for my faulty memory. Whatever work I might have ever done on one of these systems would have been before 1977 which is when I got out of automotive and into structural steel.

Re: Old Chrysler A/C

Posted: Sun May 17, 2020 12:38 pm
by bohica2xo
Ok. C bodies all have an EPR valve in the compressor suction. So during testing the low side pressure should remain constant.

I would replace the missing seal, add some dye & run it. If it seems to have a shaft leak, then you can address it.

Re: Old Chrysler A/C

Posted: Thu May 21, 2020 2:36 pm
by grumpy old man
Finally got back to the Chrysler, been a while since I have screwed with any of this. Went to the parts house to get a few items and found that there is more than one pag oil. Which one do I want for this V2 compressor, or does it make a difference?

Re: Old Chrysler A/C

Posted: Thu May 21, 2020 11:32 pm
by Al9
That's an interesting question - i know a lot about similar compressors used in bus/coach applications - the Bock FK40 and the Dorin 4T as examples. These ones run on a POE (Ester) 55 oil - one that is 55 cSt thick at 100F and about 9 cSt thick at 212F. The closest PAG might be PAG 46.

Closest thing to the 525 SUS mineral oil it used to run with R-12 - about 100cSt thick at 100F and 10cSt thick at 212F- is Ester 100 oil, however.

If you're choosing the PAG, ensure to use a quality double end capped PAG and to flush your system as thoroughly as possible. Oil flush the old compressor with whatever oil you've chosen.

Also, don't forget that R-134A needs barrier hoses. I hope that whoever did the conversion replaced hoses.