Thanks for the help with my A/C problem. I finally got it finished. Anyone who is attempting a conversion/repair to R134 might have the problems I did.
After a pump inspection(it was good), rebuilding the hose, new seals, and adding the R134, I still had warm air. I made sure all of the vaccuum operated vent doors were working, that I had charged the system with enough R134, still warm air. It turns out that my VIR unit was shot. I was going to rebuild it but could not order all of the essential parts for a rebuild. So, I bought a remanufactured unit. $161.00 at Carquest. Dealers could not even locate one.
Every other parts store just laughed at me, and told me how outdated my system is and how it would be impossible for me to find one. At any rate, its fixed and working excellent! Anyone who needs any advice, I have suddenly become some kind of expert(after hours of knuckle busting, internet surfing, forum posting and manual reading!!).
Again, thanks for all of your help in this project!

 

Let me be the first to ask a question to the A/C expert. Is there a kit you can buy to convert to R134 or do you buy all new hoses and replace them? I'd like to be able to fix my A/C myself and not have to take it to a place to get the old freon any more.

Thanks,
Matt

 

I got a VIR from Zip here on the forum store. Not sure if they have it for all vehicles. My car is a 1976. Just in case anyone else has the same trouble you did finding the part, you may want to check right here.

Jeff

 

Great job Elvis.... (yup, I remember the Elvis tail art :D :D :D ) So... what is the VIR? For a $161.00, it sounds like a compressor.

 

Golden80, You can get a kit at Walmart, or any auto parts store. Mine cost $34.00. I had the hoses rebuilt only because they were pretty cracked and looked kike they had been leaking. The kit has 3 cans of R134, 1 can of oil, the new style filler hose, and various fittings needed for conversion. All you have to do (provided your system is in good shape) is replace some O-rings, some fittings and recharge. The directions are pretty straight forward.
Wanderer, the VIR is the cannister which contains the POA valve, Expansion valve and the dessicant bag. An expensive P.O.S.!

 

VIR stands for "valves in reciever". It is basically the reciever dryer but they have incorporated the expansion valves into the top so you have to either rebuild or replace everything. I switched my 73 over to 134A last year after $200 worth of R-12 and oil ended up all over my garage floor :cry . I was able to get the VIR from Orielly auto parts, but I do remember that I had to get the book away from the teenager at the counter and look up the part myself, then they had to special order it for me.
R-134A works reasonably well in my vette up to about 95 degree temps, but can not really keep up with 100 degree+ Texas summers.

Kevin

 

I've been considering this mod to my A/C also. This is a really great place to get information!!

I wonder how I got along way back when before the internet opened up communications on "common" issues. :lol:

 

One more question. Can I drain the freon myself? Or does this need to be done somewhere?

Thanks,
Matt

 

Whenever I ask this question, nobody ever responds...Must the R-134 adapters remain on the charging points, or can they be removed until needed to check the system? The question is relevant to a judged car; point deducts are very likely for the presence of the adapters.

 

Chuck, the ones I've seen just screw over the R-12 Schrader valves, so I guess they could be removed for judging purposes. The real question is the "STICKER" you are required by Federal law to apply to the compressor showing that R-134a is in the system. If you do the conversion yourself then it can be a non-issue (unless you are afraid the Freon police will start doing underhood checks :D ) But if you get the conversion done at a shop then they'll apply the sticker.

 

This is off the subject, but with that handel, I assume your a Jimmy Buffet fan.??? I am.

 

Thanks Steve, I was looking at a conversion kit at Pepboys, and I felt that the adapters could probably be removed without a problem, but needed confirmation.

Shoot no, I ain't worried about no "Freon Police"...getting away from the "Freon Police" making me pay big bucks is why I want to do the conversion in the first place...and, of course, it's so much better for the environment too. :D :D

Has there been feedback about long term experience with R-134 in systems with original hoses in good condition? I have heard some say that R-134 will leak through original material hoses because the molecules are smaller or something.

 

What's the best way to evacuate the R12 (that's the freon, right?) Can you just pour it out, put in the kit, then the R134, and everything works? Or does the system need to be completely flushed of the R12 in some way? Where do I drain the R12 out from too?

Thanks,
Matt

 

You need to have your system evacuated. I've read that 2 hours of vacuum is recommended to remove all the R12. After that, seal the system and watch for leaks ... the vacuum will begin to fall off.

 

Legally, R12 must be evacuated by a "recovery" system that sucks it out of your system into a holding cylinder. It doesn't "pour" out... it comes out as a gas if/when vented to the atmosphere (i.e.- it "boils" out). But... that is illegal. Not that I care.... I don't buy into the DuPont/Montreal Protocol view of the Universe. If you end up with a slimy residue on your floor or elsewhere, that is the refrigerant oil, not the R12.

 

I have heard that most shops will probably evacuate the R-12 from your system for free since the stuff is so valuable now (around $50.00 a pound), but mine evacuated itself out of a broken hose.
The service ports just screw onto the schrader vlaves, but most of them have some kind of loctite type thread sealer in the threads when you buy them that makes it difficult to remove them without boogering up the thread.
To do the conversion you need to do a little more than just change the service ports. R-134A is not compatable with the oil that is used with R-12 so you need to drain all of the oil from the system and replace with a compatable oil. The compressor needs to be removed to drain all of the oil out of it, and since the receiver dryer holds a significant amount of oil (and since the system has to be opened to the atmosphere anyway) it must be replaced. The evaporator and condensor should be flushed (very messy job) and you should replace all of the o-rings when you reassemble. It would also be a good idea to replace all of the rubber hoses too, mine looked fine the first time I did this but they failed a week later and cost me a lot of money and time.
It is also a good idea to pull a vacuum on the system before charging to check for leaks and make sure that all of the moisture is removed. I was able to borrow a vacuum pump, and the low pressure side of the gauges I bought double as a vacuum gauge so I was able to tell how much it was pulling.

Kevin

 

Chuck,
Whenever I put the adapters on I had to remove the little valve stems inside the old valves. If I removed the new ones now, all of my R134 would bleed out since ther is no form of a check valve anymore.
Strike3, Buffett Rules!!!!!

 

Hi, Al, I was hoping that the adapter just screwed on over the original charging valve and disabled the Schrader valve by depressing it to the open position, and then used a valve built into the adapter to prevent loss of refrigerant. This would permit you to charge the system with R-134, and then remove the adapters, and the original Scrader valve would close when the adapters were removed preventing the refrigerant from escaping.

The manufacturers of the conversion kits use thread locking compound on the adapters, and may instruct you to remove the Scrader valve cores to SPECIFICALLY PREVENT removal of the adapters. If the car later changed hands to someone that wasn't told or didn't understand the significance of the fact that the system had R-134, they could bring the car to a shop leading to erroneous charging with R-12 resulting in mixing of the refrigerants.

I'll check out the details when I get ready to reassemble the AC. :D