951Tom

With summer fast approachng, it's almost time to get the A/C fixed. I want to try & convert to R134a. It needs a new hose too. I can see oil around the compression fitting near the shock tower. Any good websites about this whole process?

It's the oil I don't know anything about?!? How do you measure the amount of oil you're putting in? How do I get all the old oil out?

My mechanic wants $700 to convert & install the new hose...should I just let him? I'd rather do it myself. I can do the hose & all new o-rings, it's adding the freon/oil part I've never done. I added some R12 freon once to my old GTI but that's a lot easier. Any input would be appreciated if you've done this before. Thanks!

Travis - sflraver

I just did mine, the cheap and dirty way. I was running r-12 and I had a few cans that I just recharged the system with.. but it all leaked out. So... Instead of wasting more r-12 I went down to discount auto and got a r-134a conversion kit ($34) and a can of dye. There was no pressure in the system after the other stuff leaked out so I put in a can of the 134a and then the can of dye. I let it run for about 10 min then got out my black light. My lieak was right at the dryer. I tightned up the connection and now it seems to hold. Anyway, the conversion kit comes with new adaptors that go right ontop of your r12 ones. The cans that come with the kit have stop leak and oil already in them. I added the other 2 cans and now everything is fine. They say you are suposed to get a bigger evaporator when you switch but I just left it how it is. Been working for 2 days now but I'm keeping my fingers crossed.

led

How does it compare? I've heard that r134a doesn't cool as much as r12, is it true?

mrmunky

i'm interested in this as well.. keep us updated.

Travis - sflraver

The R-134 gets down to 48 when I check it at the vent. I am running into a problem with the compressor kicking on and off to fast, on 5 sec then off 5 sec but I have an email out to someone who I think can shed some light on this. When he gets back to me I will post it up. Will probably be tomorrow though.

Bri Bro

I've heard that r134a doesn't cool as much as r12, is it true

Yup, R12 does cool better then R134a.

led

So why would you make the change?

Travis - sflraver

you live in puerto rico... r12 is available there. Here in the real USA the stuff goes for around 50-75 for 12oz.. when you can find some old cans from the late 80's.

edit: the above "real USA" sounded kinda bad... just wanted to let everyone know it is ment as a joke.

Mark Lue

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by 951Tom:
<strong>With summer fast approachng, it's almost time to get the A/C fixed. I want to try & convert to R134a. It needs a new hose too. I can see oil around the compression fitting near the shock tower. Any good websites about this whole process?

It's the oil I don't know anything about?!? How do you measure the amount of oil you're putting in? How do I get all the old oil out?

My mechanic wants $700 to convert & install the new hose...should I just let him? I'd rather do it myself. I can do the hose & all new o-rings, it's adding the freon/oil part I've never done. I added some R12 freon once to my old GTI but that's a lot easier. Any input would be appreciated if you've done this before. Thanks!</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">The biggest issue seems to be with the oil that is used with the different gases. R12 uses an ester oil and R134a uses a synthetic oil. It is recommended that you remove as much of the ester oil (more that 70%) before converting the system as the old oil may react with the R134a and gum up the compressor.

mrmunky

led, r12 is outdated and you cant really get refills for it anymore. all modern vehicles have r134a.

led

How would you go about removing the ester oil?

sflraver: no offense taken.

951Tom

sflraver, you may have too much freon. Your high pressure switch is turning off the compressor too early. Did you hook a gauge set up to it? Same thing happens with too little freon.

I've heard our cars take very well to a R134a conversion. Vent temps can still be below 40F if done properly.

Travis - sflraver

hold pressure with the car off has me at 150lb on the high side and 100 on the low. Is this in the correct range? I am new to this stuff also but I tend to jump into things. I learned more about auto ac in the last few days then I ever cared to know.

F18Rep

The one thing you guys haven't mentioned is pulling a vacuum on your system prior to filling with 134. One of the reasons that you might want to do that is to help get any moisture out. The moisture tends to collect at the expansion valve and freeze, only takes a tiny bit and if this happens it momentarily blocks the system and the compressor "high side" pressure jumps, which then kicks off the compressor until the ice melts, system pressure balances and the compressor comes back on. The cycling is normal but probably should be as something more like 1 minute on, 15 seconds off. If your system is freezing (like above) then it won't deliver really cold air.
The other thing is that 134 is a smaller molecule which means that it can go through the rubber used for the hoses of R12. That means that you will have to refill more often, if you're serious about 134 then you might want to get the newer type hose (goodyear is one maker). Also, might want to keep this in mind when you buy O-rings. That is exactly what I'm in the process of doing. Just got the old hoses out yesterday, what a pain....Bruce

tod84944

Has anyone tried any of the "duracool" that is advertised in excellence. The guy that sells it in excellence is here in Nashville and I have thought of trying it. He advertises that it mixes with r-12 just like the real stuff.