Broken A/C troubleshooting

[Gaspowered]

As Tom suggested above, I'd put gauges on the system and check the pressures.
If it's low, you may be able to add some refrigerant and get away with it for a while.
But if it is low, there's a reason it's low.

Cheers

Edit:
If it is filled with R12, then you must use R12 unless you do a full conversion to R134a.

[BennSport]

Thank you, I appreciate everyone’s help on this! Will r12 pressures at the varying ambient temps fall under the same as r134a? Also would this be a reputable r12 source? I don’t know how to vet out the legit vs fake stuff

https://www.amazon.com/Arctic-Air-R12-A ... BYFQ&gQT=1

[Gaspowered]

That's not actually R12.
I believe it's a mixture of propane and isobutane.

Will it work??
Sorry, I have no idea.

I recommend if you have the time and a few extra dollars, you should do the 134 conversion.

You may be throwing good money chasing after bad results

Cheers

[BennSport]

Okay I’ll just proceed with the conversation then, thanks for all your input. Just to confirm will any reciever dryer work as far as a r134 conversion goes?

[Gaspowered]

I don't know about "any", but both Griffith's and 944Online have driers that will work.
(links posted above)

Cheers

[Tom]

Enviro-Safe has a long controversial history. One of their 'refrigerants' is pure propane, and most are hydrocarbons of one kind or another (i.e., flammable). It's not legal to sell the linked product as an r12 replacement for cars, due to the fire/explosion danger, and they got in trouble previously for doing so. If you look, they technically market it as an r12 'booster' or 'supplement' etc., which is a pretty flimsy technicality/loop hole. I wouldn't go that route!

Most receiver driers are r134a compatible these days. Griffiths advertises theirs as such, but it's a smaller diameter than stock so doesn't fit in the factory bracket without shimming it. I recently installed the BEHR receiver drier, after writing to the company and confirming their TH 9 desiccant is indeed r134a compatible. It fits and is well made.

https://www.pelicanparts.com/More_Info/ ... 7cQAvD_BwE

[Tom]

Our host (@Tom) has a pretty good thread on what he did to the a/c on his 944 turbo.

viewtopic.php?t=425

If you're planning on keeping your current compressor, I'd remove it and drain all the oil out, clean it and put in a pag or esther oil.
I would also get a conversion kit, new barrier hose and new drier.

Here are a couple dependable of sources;

https://944online.com/

https://griffiths.com/


Here's a good video to watch as well.



Cheers

Took the words right out of my mouth.

You might also consider a parallel flow condenser if converting to r134a in a hot climate -- it will get the temps down to freezing. In more moderate climates, the factory condenser still does a pretty darn good job on r134a.

Cue @dr bob for a master class in automotive a/c!

[BennSport]

How likely would it be that another component in the system is just broken? While I do want to follow through the conversion, it would be unfortunate for me to go through all the trouble of refilling just for it to be wasted finding out something like the evaporator is broken.

[Tom]

How likely would it be that another component in the system is just broken? While I do want to follow through the conversion, it would be unfortunate for me to go through all the trouble of refilling just for it to be wasted finding out something like the evaporator is broken.

Fairly impossible to handicap that based on the available info. Since the clutch kicks on when you turn on the A/C and you get a hiss from the Schrader valve, there's a reasonable chance your car is just low on refrigerant. Those are both pretty good signs. Do you notice any cooling effect at all if you turn on the a/c and drive for a few miles? If so, you 'could' throw $100 at it and try just adding a can or two of r12, if you can find any. But that's an all or nothing gamble --if it doesn't work the $100 is just wasted and doesn't get you any closer to a working a/c. You could also take it to a shop to have it diagnosed. If it were me, I'd give up on r12 (just too hard to get) and commit to r134a. Once over that mental hurdle, I'd evacuate the system and pull a vacuum on it. That will tell you if you have leaks (before buying anything). You probably have some leakage -- most older systems do. Fixing leaks is often just a matter of changing o-rings here and there. So that would be a cheap step 2 to get the system sealed up. You can then turn the a/c compressor by hand and make sure it is creating at least some compression at the ports (to assess the odds that the compressor is bad). With no leaks and a probably-ok compressor, your odds of being successful with a r134a conversion would be pretty good, say 87.62%.


https://www.harborfreight.com/search?q=Vacuum%20pump

[BennSport]

No, there is no cooling effect at all even after driving for a bit. If the o rings are a necessary part of the 134 conversion, would it be redundant to pull a vacuum with the old ones still installed?