Author Topic: Need help with A/C (Read 4536 times)

seeohngee · « **on:** June 05, 2010, 02:53:33 PM »

Ok... So I'm pretty new with cars so I don't really know much but I'm learning. I can do the typical oil change, brake/rotor change, tire rotations and some belt changes.

The summer is here and I just recently installed my A/C belt since it wasn't there when I purchased the car last fall. After I installed the belt, I turned on the AC but it didn't blow out cold air. I read that the older cars uses R12 refrigerant so I went around to search for some and I guess they're impossible to find unless you buy them online(Freeze12). I spoke with someone and they recommend me switching it to R134 since it will be cheaper and a lot easier to find in stores.

This is where the trouble comes in. I'm not sure whether I should buy the R12 online ($40) and test it out or should I just save that money and change it to R134.

If I were to change it to R134, I have no clue what to do (ive done some research, but seems a little confusing) and what I would need to switch it over. If someone can give me some input, I would be really grateful!

BlueBMW · « **Reply #1 on:** June 05, 2010, 08:23:43 PM »

Just take it somewhere that will suck out whatever is in there, replace the fittings with 134a fittings, and recharge with 134a. Some say you have to replace the compressor and seals etc, but i've seen it work numerous times without anything. Having the receiver dryer replaced wouldn't be a bad idea though since it sounds like the system might have been empty for a while. Also, the same place could pull a vacuum on the system to get an idea of what kind of, if any, leak you might have.

Its not really DIY work since you need equipment and certification to handle the refrigerant.

DesktopDave · « **Reply #2 on:** June 05, 2010, 08:39:25 PM »

Those are your choices...either some aftermarket compatible refrigerant or the usual r134 conversion. You might luck out with an OEM conversion kit, but they're pricey.

I haven't done it myself, but I have done a lot of research. I'm told that we have Seiko A/C compressors that are compatible with both refrigerants. Check that you have the right compressor first.

Next, get the system purged of any residual r12 at a mechanic. It'll give you instant burns if you get high-pressure oil on you, so make sure the system is fully purged.

Then you'll need new o-rings, a new dryer and a new set of pressure switches. Install them, then have your mechanic do r134 and the right PAG oil for the compressor seals.

If you wait a little while, I might have it one with a step-by-step. It's getting hot here, I need some chilling.

///m42 sport · « **Reply #3 on:** June 05, 2010, 09:14:13 PM »

you do not have to replace the o rings. extensive discussion here
http://www.e30tech.com/forum/showthread.php?t=58110

My ghetto approach was not to mess with anything. I just slapped on a r134a adaptor on the low side...available at autozone, oreillys, etc. Filled with r134a and its blowing ice cold ac.

tjts1 · « **Reply #4 on:** June 05, 2010, 10:24:09 PM »

Quote from: seeohngee;93282

This is where the trouble comes in. I'm not sure whether I should buy the R12 online ($40) and test it out or should I just save that money and change it to R134.

Buy the R12 for $40. Its way cheaper and easier than converting. I used duracool with very good results.

BlueBMW · « **Reply #5 on:** June 06, 2010, 07:39:09 AM »

So it looks like you have three choices!

The proper conversion method as per DesktopDave
The ghetto conversion method as per ///M42 sport
And the traditional method as per tjts1

The choice is yours, and yours alone! But choose wisely!

longtallsally · « **Reply #6 on:** June 06, 2010, 09:42:02 AM »

My money is on you having bigger fish to fry. Check this out:

http://www.e30tech.com/forum/showthread.php?t=82528

If you have any history at all on the car you should look there to see what is the what.

A little quick info:

R12 is a better refrigerant for cooling than R134a, but is STUPID expensive generally and WAY illegal to be messing with on your own any longer (as I mention in the above thread, on the order of a $25k fine). As Dave mentioned, the O Rings usually have to be changed to work with the R134a. I didn't change the O Rings on my last E30- '89 325is- when I had a shop do the conversion and it blew CRAZY cold and was under $200 for the repair.

On my current 318is I flushed all the lines, changed all the O Rings, the receiver/dryer, the expansion valve, and eventually the compressor and then had a shop pull the vacuum and fill it. Not that I need AC here in Germany much since it's generally so flippin' cold and always raining, but it works really well.

IMO, you will need at the very least to change the receiver/dryer and probably put in a new expansion valve to do it somewhat correctly.

Dave, the compressor in mine was a Nippondenso and I replaced it with a new one. Read; OUCH!

seeohngee · « **Reply #7 on:** June 09, 2010, 12:50:01 AM »

Thanks for the reply guys. I think I'm going to just get r12 refills online and hope that it still works. If it doesn't then I guess I'll just wait for a write up to be posted on here.

Thanks for the link long, I'm going to check it out before I purchase the r12.

Murdul · « **Reply #8 on:** June 09, 2010, 11:59:16 AM »

The PO of my car had the system charged with r134a at a shop and I have the receipt. It was not very expensive, I'd quote but the receipt is at home. If I remember correctly it was less than $100 bucks. So obviously they did not comb over it and I have no problems.

DesktopDave · « **Reply #9 on:** June 09, 2010, 01:57:45 PM »

A friend has a free set of o-rings, I might do this soon & post a few pics (if it works). I'm not sure if the Jaguar XJ6 set is perfect, but how different can they be?

longtallsally · « **Reply #10 on:** June 10, 2010, 04:00:52 AM »

Quote from: DesktopDave;93391

A friend has a free set of o-rings, I might do this soon & post a few pics (if it works). I'm not sure if the Jaguar XJ6 set is perfect, but how different can they be?

Why bother? The correct kit is $18 from Pelican.

To pull the vacuum and charge with 134 was just under $100 for me at a shop in CA, where everything is more expensive. Aside from the massive amount of time it took me to do the whole system, the only big expense for me was the compressor at $400. Now that it is over 80% humidity every day in Germany, I'm glad I invested in it.

DesktopDave · « **Reply #11 on:** June 10, 2010, 09:30:42 PM »

I'll bet it's a universal o-ring kit from Pelican or elsewhere...though it's nice to know it's pretty cheap. Wonder if it has the new label? Looks like it claims to. Replacing it all at once gets a little pricey, $80 in parts even if the entire system is intact. I'm a pretty cheap bastard, that's getting up near 10% of the car's value for a little cold air!

I'll post any important pics as I go through the process.

longtallsally · « **Reply #12 on:** June 14, 2010, 04:32:43 PM »

Quote from: DesktopDave;93430

I'll bet it's a universal o-ring kit from Pelican or elsewhere...though it's nice to know it's pretty cheap. Wonder if it has the new label? Looks like it claims to. Replacing it all at once gets a little pricey, $80 in parts even if the entire system is intact. I'm a pretty cheap bastard, that's getting up near 10% of the car's value for a little cold air!

I'll post any important pics as I go through the process.

You don't mean $80 for O Rings do you? That $18 gets you all the O Rings for the whole system- EVERY line, and the manifold for the compressor. Ask me how I know.

The receiver/dryer is $18 and the expansion valve is $25. That's under $80 in parts- unless you are unlucky like me and the compressor was bad...