A/C Help

[BanjoDude]

Hi guys. Got my wiring cleaned up a fair bit yesterday. Back looking for some help this time with aftermarket a/c. The PO said the a/c works, but he didn't use it often, so he took the belt off. I'd like to restore it to working order if I can, keeping it as "original" as possible (I know the unit isn't factory, but I like it because my Grandpa installed it 50 years ago, and I'd like to keep it the way I remember it as a kid). I tried to include pictures that show the whole system. A few questions:

1) Probably a dumb question, but where is the refrigerant in the system? With only rubber hoses held on with hose clamps, I can't understand how refrigerant comes into play here. I guess I'd expect high-pressure hoses, but I also acknowledge I don't understand completely how these things work.

2) It seems like the hoses could be cleaned up a fair bit and routed more efficiently. Is there any significance to any of the loops in the hoses?

3) In the under-dash unit, there is a bunch of mastic around a couple of the fittings where the hoses connect to the condenser. I'm assuming there is a leak of some kind there that he was trying to keep at bay. Is that something I can replace if I find that it leaks?

4) Anything else I should check out or consider?

Thanks, as always, for the guidance. I sure appreciate it!

Wes

[Getter-Done]

That is a York compressor.
I really like those.

The freon goes in in the caps on the side of the hoses right there at the compressor.

[Getter-Done]

#1 thing I remember about those is ,
Make sure they have oil in them.
Oil fill is here.

[Getter-Done]

When you are filling it with Freon ,
Here is the sight glass you use to know you got (The Air out) it charged.

[jumpsoffrock]

Although it is generally seen as sketchy, I have seen several A/C systems in cars that did not use crimped hose fittings, but just normal hose camps, typically two per end.

You can shorten the hoses to simplify things, maybe when installing the system they didn't have a proper tool for cutting the extra tough high pressure hosing, who knows.

The "mastic" you see is typically "butyl wrap", a tar-like substance that is used for insulation. The item it is covering in your photo is a TX valve(TXV; temperature expansion valve), which controls the flow of refrigerant. TXV's have a small copper capillary tube that senses temperature, and in order to give the capillary tube the most accurate environment, they often used butyl wrap to insulate the capillary tube to the corresponding refrigerant line inside the evap box.
in other words it's normal, yes it looks funky and gooey but that's normal.

[Steeveedee]

The fittings are barbed, so seal with the hoses at the ridges. These type hoses leak more than the crimped hoses, so the system may be pretty much empty after all this time. It is usually at about 100 psi at ambient temperature when the compressor is not running. Do you have gauges or access to refrigerant? Pretty sure that that only had R-12 in it, since it doesn't have the newer fittings for 134.

If I had to guess, the hose length would come into play as strain relief. If there is too much side force on the hoses, they will leak at the fittings sooner.

[howzzzit]

A couple of things. If it's 50 years old it used R-12 refrigerant which is long gone. You can't convert to R-134 with out changing o rings and oil. Also, the EPA has gone after R-134. That's why newer cars use a newer refrigerant which YOU cannot buy at the local auto parts store. Buy a cheap a/c manifold and hoses at Harbor Freight. Hook it to one of the ports and see if there is any pressure in the system. That will tell you if all the refrigerant leaked out. If there is still some pressure that's a good start. Regardless, it would be a lot of work to convert to R-134. Do you know if your Granpa did the conversion? If you do convert you'll have to use oil specifically for R-134 automotive. Don't mix with what you have. In fact they won't mix. My 72 still has the Frigidaire compressor and pumping R-12. Had a double lip seal installed in her and no leaks. Gets with it.
Another note. If the system is flat (empty) you'll have to find the leaks. Gushers are obvious and and you can usually see oil around the leaking spots. Very small leaks will require a leak detector. Then when you think you've found all the leaks you'll need to pull a vacuum with a vacuum pump through the manifold you bought and see if the vacuum holds. If so, you are good to proceed. I'm sure you don't have a vacuum pump, but maybe you could get your friendly a/c repair shop to pull the vacuum for you?
Another post stated to foam you might see in the sight glass is air. The foam you might see is refrigerant that is boiling off too soon. You need a clear sight glass which means you have pure liquid refrigerant coming from the liquid receiver to the expansion valve. Expansion valves need full liquid no bubbles.

[BanjoDude]

You guys are awesome. Thanks so much. I do not think he converted to 134. The tag says R12, so I'm assuming that's what is in it. Would there be a way to know for sure without emptying and recharging? I have a friend with some gauges for home a/c. I wonder if those would work. If not, I'm sure I could track down a set.

[howzzzit]

Your friends gauges would work. If you took a pressure check on a cold truck for example.

70 ambient R12 is 70.1 lbs psi and R134 is 71.1 lbs psi. You still won't know. Psi too close between the two refrigerants. There are analyzers for a few thousand bucks. We used to use them. I'm sure you don't want to buy one.
Looks like you need to start from scratch and use R134. I would buy some extra if you do go that way. Here's a link to make your head spin.

https://www.epa.gov/mvac/refrigerant...mental-impacts

[Steeveedee]

There are replacement refrigerants for R12. I'd go that way instead of converting to 134.

https://www.google.com/search?q=r12+...hrome&ie=UTF-8

[Getter-Done]

On a side note:

My Daddy used one of those compressors to have on board air on his truck.
This was to run Impact guns and air tires up and stuff.

He put a Filter on the intake and routed the output with hoses to the
tanks he mounted under the truck with a pressure switch inline of course.

With that said

If you wind up have to go to another system because R-12 is hard to come by.

Don't throw it away.
It has some value.

[howzzzit]

Check out some of the R12 substitutes. R134a and R12 are what they call "true" refrigerants. Most subs are blends of 3 or more refrigerant components that boil off at different points in the system as they absorb heat. They work in a commercial refrigeration system, but so so in automotive. There is no such thing as a "drop in" for R12.

I rant on

[Wrenchbender Ret]

Those caps on the compressor outlets have valve cores behind them like tire valves (not interchangeable). You could poke a screwdriver in one & see if it has any pressure. Do not take the oil fill plug out unless the unit is out of freon. The oil circulates with the freon. Check to see if the compressor turns. Spin the pulley. It should turn freely with no brg. noise. Run a jumper wire to the comp. clutch wire. It should lock the pulley to the shaft. Turn the pulley by hand . It should turn firmly a couple of turns without locking up. Check the controls. Turn on the controls with the key on to see if the blower works & the comp. clutch kicks in.
If all that is good you might get someone you know to add freon & oil. Oil is available in pressure cans to add without discharging the system. Freon 12 is still around on the black market. Those units only held 2 lbs.

George

[Getter-Done]

Originally Posted by Wrenchbender Ret

Those caps on the compressor outlets have valve cores behind them like tire valves (not interchangeable). You could poke a screwdriver in one & see if it has any pressure. Do not take the oil fill plug out unless the unit is out of freon. The oil circulates with the freon. Check to see if the compressor turns. Spin the pulley. It should turn freely with no brg. noise. Run a jumper wire to the comp. clutch wire. It should lock the pulley to the shaft. Turn the pulley by hand . It should turn firmly a couple of turns without locking up. Check the controls. Turn on the controls with the key on to see if the blower works & the comp. clutch kicks in.
If all that is good you might get someone you know to add freon & oil. Oil is available in pressure cans to add without discharging the system. Freon 12 is still around on the black market. Those units only held 2 lbs.

George

Glad you mentioned about not taking the oil plug out unless out of Freon.

I still have a little R 12.

Here is some pictures of the Internals just because I still had it in the scrap pile.

[Wrenchbender Ret]

Thats the first time I have seen the insides of one of these. Interesting. Is there any dipper or pump to get oil circulating or does it just circulate with the freon?

George