Any AC gurus in the house?

Cross post from the other side

Scenerio:

'92 Cappy with an R-12 system.

Bought a reman compressor off a forum member that I trust.
Flushed the system, blew it out, put all new O-rings and Accumulator (receiver/drier or whatever you wanna call it).

Hooked it all up and ball parked my 6oz of oil (proper for R-12), vac it out and it held vacuum.

Followed FSM and warmed up the car, and dropped some gas into the system and the clutch started popping and in and out until the pressure rose and it ran continuously.

Here's where the question comes in. My 'gauge' was home made by my Dad and the dial has pencil markings that stop at 40PSI where the needle pegs. I ran the system for about 5-10 min and a noise started then the clutch starting kicking on and off fairly rapidly.

I'm thinking I have too much pressure, but don't want to waste any if I don't have too.

Unfortunately, the nice set of gauges I have are for 134a and don't fit on the R-12 fittings.

Questions:

On a R-12 system what is the proper operating pressure (didn't find in FSM)

What PSI are the 30lb cans kept at? (yeah I'm sitting on a gold mine, lol).

lol There was one on Jacksonville's Craigslist (a 30 lb canister) for $50. I wish I had the cash to grab it when I was there.

I found this link: http://www.vintageair.com/DownloadsSection/Documents/Troubleshooting%20Guide.pdf

It says for R12 that high side is between 140-230 PSI and low side is 12-15 PSI.

Hope it helps.

You can get a set of R134a fittings at walmart for a few bucks, just put one on the low size to measure the pressure with your good gauge.

If the clutch is kicking on and off rapidly, that usually means you need add more juice. (from my expierences)

Mine was doing that when I swapped out compressors on the OCC and *thought I had it charged up all the way*. A little more juice and it was all good to go. I think it is hard to put too much in when just using a can.

But I am not a guru though. Oh, and my OCC has been converted over to the new stuff too.

95BRMW wrote:

You can get a set of R134a fittings at walmart for a few bucks, just put one on the low size to measure the pressure with your good gauge.

I did this on a 93 Caprice . I probably should have pulled a vacuum after that since I opened the system but I didn't and it worked just fine.

going to stop by my Mom's tonight and retrieve my Dad's 'good set' I know they are in the garage somewhere.....

Chris, it was running fine, then all of a sudden.....that's why I think there is too much in there. I'm afraid if it's overfilled I might rupture something.

95BRMW wrote:

You can get a set of R134a fittings at walmart for a few bucks, just put one on the low size to measure the pressure with your good gauge.

I've seen those. I need to convert my system. How hard are they to put in?

Gotcha...

Be interesting to see if it is too full. Don't want something to blow!

brokecello wrote:

Gotcha...

Be interesting to see if it is too full. Don't want something to blow!

It might just be because its a VW. But last summer I recharged my ac using a can from Autozone, I filled it to where it was "supposed" to be. I got on the highway, turned the ac on, the car dropped about 2000 rpm and I threw a CEL. Got it home and said I blew a coil pack. Checked the coils, they were all clean. After about an hr of searching, my father checked the AC. it was too high and the compressor/engine was stalling the compressor to protect it. Turns out my gauge was off by about 10% thus I put in 10% more than I needed. Long story short I think if it was overfull it would be a lot more obvious. Thou I could be wrong.

Cadet57 wrote:

95BRMW wrote:

You can get a set of R134a fittings at walmart for a few bucks, just put one on the low size to measure the pressure with your good gauge.

I've seen those. I need to convert my system. How hard are they to put in?

The fittings simply screw in, but that doesn't mean your ready to use R-134. You have to change all the o-rings in the system from the black ones to the green ones for use with R134, and you need to replace the dryer, flush the system with A/C flush, put the system back together, have the system evacuated which will tell you if you have any leakes because it won't hold vacumn if a leak is present. If all is good fill with R-134

Hope this helps.

94 LT1 Wagon wrote:

Cadet57 wrote:

95BRMW wrote:

You can get a set of R134a fittings at walmart for a few bucks, just put one on the low size to measure the pressure with your good gauge.

I've seen those. I need to convert my system. How hard are they to put in?

The fittings simply screw in, but that doesn't mean your ready to use R-134. You have to change all the o-rings in the system from the black ones to the green ones for use with R134, and you need to replace the dryer, flush the system with A/C flush, put the system back together, have the system evacuated which will tell you if you have any leakes because it won't hold vacumn if a leak is present. If all is good fill with R-134

Hope this helps.

Ughhh. Really? Even if using that R-12 to R-134 retrofit can?

ps, check your pm's.

The gases are not compatable. I have never seen a retrofit can, not saying they don't exist, but I do know the gases are not compatible.

94 LT1 Wagon wrote:

The gases are not compatable. I have never seen a retrofit can, not saying they don't exist, but I do know the gases are not compatible.

Yeah, they sell them at Autozone here. Its a "retrofit" kit. You flush the system of whatever R-12 is in there and replace it with this 134 which I guess is safe for the o rings, etc as it does not say on the can that you need to replace them.

Man... that's not something I'd be willing to try. Specially with anything that comes from Autozone ! Those guys literally stock and sell the cheapest parts anywhere. Please don't take what I'm saying as the final word, I would call a local A/C shop and ask them what they think of that product. Even if it won't hurt the o-rings, the pag oil in the system cannot be flushed out of the dryer.


P.M sent

is the a/c still blowing cold?
jump the low pressure switch,. see if that calms the compressor,. it may just need a new switch,. they screw on and off easy enough,
i just changed one on the pickup,. about 21.00 or so if i remember,. the clutch was cycling very rapidly,.

Nick

Well after careful combing of the FSM I found the table....

I was about 4 PSI too high. I reduced my pressure from 40 to 36 on the low side and the clutch stays engaged, compressor is alot quieter, and it still blows cold (although I didn't put a thermometer on it yet).

I couldn't find the 'good' gauges, so trusted my Dad's pencil marks as he set the gauge for cars some years ago. Interestingly enough, I found 3 more of the same gauges still NIB in his garage tonight (left over from his AC school days back in the 60s).

Started up my 91 OCC and ran it to compare and noticed that compressor is a bit noisier (not freshly rebuilt).

Thanks for all the adivce and help everyone gave me...

Cadet57 wrote:

94 LT1 Wagon wrote:

The gases are not compatable. I have never seen a retrofit can, not saying they don't exist, but I do know the gases are not compatible.

Yeah, they sell them at Autozone here. Its a "retrofit" kit. You flush the system of whatever R-12 is in there and replace it with this 134 which I guess is safe for the o rings, etc as it does not say on the can that you need to replace them.

What you are probably talking about is the hydrocarbon based refrigerants, basically propane on steroids. Much better refrigerant then any of the HFCs and, despite the smear campaign being put on by the Freon manufacturers and their buds in government, are not very flamable. Actually Duracool, marketed here in Canada, has a higher flash point then 134. They will be clearly marked HC as in HC12.

This stuff has been used for over 20 years, and is now the standard in Europe and many other countries around the world. Could this be another example of big business dictating policy? Say it ain't so.

The next AC top off for me will definitely mean a conversion to Duracool or equivalent. By the way, propane is compatible with any of the seals and components used in our AC systems, R12 or 134. Just make sure your system is completely free of freon before adding. Propane and freon don't like each other.

Just use the supplied gauge, hose system and follow the instructions carefully. You will need less propane then freon but even in a 134 system, it will freeze your........off.

Bill

Now i'm not sure what to believe in regards to an R134 conversion. It seems to be split about 50/50 wether replacing the o rings is needed. The only thing that all agree on is that the system needs to be purged of all R12. But other than that most simply say apply the new fittings, attach a -134 sticker and fill with freon.

I don't make the o-rings, so I can't tell you what the difference is in the material used to make them. I've always replaced them and the dryer and have not had any problems. I would suggest you do the dryer because even after the evacuation, the R-12 pag oil is still in there, I don't you spending more than $30. on a new one, and probably $10 - 12 for an o-ring kit. Good luck.

94 LT1 Wagon wrote:

I don't make the o-rings, so I can't tell you what the difference is in the material used to make them. I've always replaced them and the dryer and have not had any problems. I would suggest you do the dryer because even after the evacuation, the R-12 pag oil is still in there, I don't you spending more than $30. on a new one, and probably $10 - 12 for an o-ring kit. Good luck.

I'm going to have to look into how to do it, i've never done O rings, or any AC work for that matter minus a recharge using those cans. Does the FSM have AC stuff?

chapter 1-B. quite alot.
Anytime I crack the system I put in a new accumulator and now with the last two I've done, the orifice tube and flush FTW!
google black death AC and see what I mean.

buy the flush from Amazon.com it was 35 for a gal vs. 80+ other places on the web.



these were out of the 134a system in my 94.

my 92 had chunks of metal at the orifice tube.

Sprocket wrote:

chapter 1-B. quite alot.
Anytime I crack the system I put in a new accumulator and now with the last two I've done, the orifice tube and flush FTW!
google black death AC and see what I mean.

buy the flush from Amazon.com it was 35 for a gal vs. 80+ other places on the web.

Guess its time to buy a FSM...

Btw, sorry for hijacking your thread with my questions.

Wow! That orfice tube looks bad. Makes me happy that the one that I took out of my 94 when I was doing the lines looked as clean as the new one.

Glad to hear that things are working well. Thanks for making me a "trusted member" lol

Jason.

jayoldschool wrote:

Wow! That orfice tube looks bad. Makes me happy that the one that I took out of my 94 when I was doing the lines looked as clean as the new one.

Glad to hear that things are working well. Thanks for making me a "trusted member" lol

Jason.

Wondered when you would chime in. Jay was the man bringing me R-12 compressor across international boundries
Only took me about 6 months to get it installed

Sprocket wrote:

Well after careful combing of the FSM I found the table....

I was about 4 PSI too high.

4psi? made that much difference eh?
glad you fixed it,.
nick

I converted my 85' C20 pickup to R134a. The AC has not worked in about 10 years. I bought one of those 134a retrofit kits, charged it (no vacuum) and it worked. It leaked out a few weeks later, so I added one of this AC leak stoppers. That was almost 3 years ago. I drove the truck yesterday and the air is ICE cold still. I am not saying the way I did it is right, but it worked for me.
Now when I replaced the compressor on my RMW, I replaced the drier and orifice tube, then paid a shop to vacuum it and charge it.

95BRMW wrote:

I converted my 85' C20 pickup to R134a. The AC has not worked in about 10 years. I bought one of those 134a retrofit kits, charged it (no vacuum) and it worked. It leaked out a few weeks later, so I added one of this AC leak stoppers. That was almost 3 years ago. I drove the truck yesterday and the air is ICE cold still. I am not saying the way I did it is right, but it worked for me.
Now when I replaced the compressor on my RMW, I replaced the drier and orifice tube, then paid a shop to vacuum it and charge it.

I think what I am going to do is try the retrofit kit, if it takes great. If not, then do new o-rings, etc. Then again, its a 17 year old car. AC is a luxury

Cadet57 wrote:

AC is a luxury

maybe where you live When the day starts at 85F, It's pretty toasty in my greenhouse by lunchtime!

So something is still not right with it. It's only blowing around 67 degrees and when I put the thermometer in the Olds, it's blowing around 9-10 degrees cooler.....hmmmm.

I have a line on a good set of R-12 gauges I can get ahold of to use over the weekend.

Small bump...

I bought those R-134 retrofit fittings at Autozone. I'm looking in my FSM but I cant figure out which side is the high and which is the low.

Low is on the accumulator, high is on the hose.

the 91 I'm bringing to fest has been changed over. had the retro fit fitting on the low side, no stickers or anything about a retro fit, but I changed the schrader valves (high side would hiss when I unscrewed the dust cap) and dumped two cans of 134a in there and it's nice and cold!!!

woooo AC for the trip. everything else still looks the same as my R-12 set ups.

I have AC! Bought the kit at Wally World, swapped out the fittings, sucked down two cans of -134 and now its blowing nice and chilly. Yay!