AndyK

My compressor leaks freon. I had it charged 2 summers ago, and it's almost empty now. The system itself is fine, and when it was charged, it cooled the car perfectly for a year plus.

Question is, if I get a new compressor, or a good rebuilt one, since the rest of the system is working, can I get away with replacing just the compressor and maybe the dryer, and leaving the rest intact??

Also, if I am seeing those bubbles in the little view window, can I assume that there isn't much freon left, and I can remove the compressor myself? My plan is to remove the compressor and dryer, replace them, then get them charged with the old freon--only paying to have the system charged.

Does this make sense, or is my empty assumption wrong? I don't wanna release freon into the air, or, get it in my face when I pull the plugs, etc!

Porsche-O-Phile

Your other components are likely okay, but there's no way to tell until you replace the compressor and drier and have a leak test done on the system. Do the compressor & labor yourself. This is where a shop will rape you. You'll save about $1,000 on that. Take it in once everything's installed and tell them "I just replaced the compressor, I need a vaccum test". This should cost about $50 or $60 at MOST. If it passes the vaccum test, fine - you can have them charge it or do it yourself (with either r134, freeze-12 or another "synthetic" refrigerant of your choice). If you want r-12, you'll have to have them do it ($$$). If it doesn't hold vaccum, hopefully they'll be smart enough to check the hose connections to the compressor & drier (since you told them you just replaced them), tighten them as necessary and be done with it. Those hose connections take a LOT of force - don't be afraid to rip on 'em when you tighten them down. I don't know if there's a torque spec. for them, but I'd guess it's well over 90 or 100 ft-lb.

If you're interested in freeze-12 as an option, let me know. I'll be converting both my cars to this system shortly.

Porsche-O-Phile

Oh, BTW - be careful when buying the receiver / driers. I've bought one replacement from a local vendor and it was a crappy remanufactured one with NO sight glass. What a stinkload. INSIST on one with a sight glass - you'll want it. I believe Paragon sells ones WITH the sight glass, but call them first. Again, let me know if you're interested in thi, as I'll be ordering these in the next month or so for my own cars.

AndyK

So, is it hard to remove the compressor and dryer? Any tips?

Also, when I brought the car to the mechanic when I bought it in the summer of '03, they tested the A/C with dye, and said the compressor was leaking. They charged it with R-12. I would go with R-12 again, especially since it will only be replaced ONCE when the compressor doesn't leak anymore, right!

AznDrgn

Piece of cake to take out the compressor and drier. Just loosen the tensioner, take the belt off and I believe there are two mount bolts and two line bolts take them off and it'll practically fall out. The drier line I believe runs all the way around teh engine bay until it goes into the firewall so that might be a pain. Just as a side note it is ILLEGAL to just open up a line and dump refrigerant into the air legally you must have it reclaimed. If I were you I would hold off on the swap until this spring and then have the system recharged again but this time tell them to use UV dye in it so you can find the leak. R-12 is expensive and there is no sense in changing out parts that you don't need to be changing. I have a compressor out of my '89 S2 parts car that was holding charge after sitting for 2 years so I know it doesn't leak but I never got the car to run to I couldn't say if it works right or not but everything is free so I would assume it would work. It is a reman and if you are interested I'd be willing to sell it cheap.

Porsche-O-Phile

Go with a Sanden compressor too, then you don't have to deal with those freakin' carbon-faced seals on the Nippondensos that always fail / leak.

AndyK

I'm not sure I'd want to throw in an old compressor, not knowing if it works right or not. Waiting till the spring is a good idea, but spring is only 2 months away! I figure getting a shop o fix it now will be easier - since it's cold out and nobody's thinking A/C at this point.

Aren't Sanden's not a direct bolt-on replacment? I was thinking rebuilt OE for ease-of-install. Do all the Nippondenso compressors leak - even the remanu ones?

badass951

If you see bubbles in the window on top of the receiver drier it means there is air or moisture in the system, which can cause hydrochloric acid to form. If I were you I would check out the whole AC system part by part.

Charlotte944

BIG TIP: If you have never worked on an A/C system before have someone help/show you what to do.

From an EPA stand point, it is against the law for an non-certified "technician" to release a CFC-based refrigerant into the atmosphere. Additionally, since you want to replace the compressor, have the system converted to R-134a. R-134a is less expensive (R-12 runs about $60.00 to $70.00 PER POUND while R-134 runs about $6.00 per can.) and you can get R-134 and compatible oil at places like Wal-mart, PepBoys, AutoZone, etc.

I have converted three 944s (2 NAs and one 951) to R-134, but then again I've been working on A/C systems for quite some time, and I have all of the proper tools.

To get more/better information try here :Griffith's

AndyK

The manual says bubbles showing in the drier window mean refrigerant is low.

I was told R134 doesn't cool as well as R-12 in our cars (which were designed for R-12 use)? If it's complicated, I may have to have my mechanic do it - I have zero knowledge of A/C repair. I can buy the compressor and drier, and have him do the install. Better than me messing it up somehow.

Porsche-O-Phile

Ahhh. . . the old 134 versus 12 argument. . .

He's correct in saying that r12 is ungodly expensive - and you CANNOT do any work on those systems (legally) yourself unless you feel like filing the paperwork with the EPA to get a certification. From what I'm told, it's not a big deal, but it's still a hassle. Anyway, the general concensus seems to be that r12 is what our systems are designed for and work best with. R-134a will work, but not as well (but it's much cheaper and you can DIY). Personally I'm going to go with a synthetic r-12 called "freeze-12" (you can search online for it) that supposedly has much better performance than r134a without the cost and environmentally damaging properties (affinity for ozone) of standard r12.

The Sanden compressors require brackets (often sold as part of "conversion kits", sometimes not - ask) but are very straightforward bolt-on applications with those. Also keep in mind that the Sanden compressors sold as part of "r134a conversion kits" are NOT the Sanden compressors designed specifically for use with r134a - they have r12 fittings, r12 seals, and are charged with r12-compatable oil. Now, this raises the point that compressors are largely interchangeable. Putting r134a into such a compressor is unlikely to make it fail however the POINT is that Sanden offers a compressor DESIGNED specifically for r134a - this is NOT the one that comes typically in the kits (ask me how I know). This is also one of the reasons I'm going with the freeze-12, since it's closer to what the compressor (and rest of the system) is really designed for than r134a. It's also reasonably cheap.

AndyK

Hmmm...what is this Freeze-12? Can my mechanic get it, or is it some secret military substance?

I am leaning more toward either paying for R12, or your mystery Freeze 12. R134, cheap as it is, wont work as well. I already have a compressor that doesnt work that well. I want it to work like it did when new!

Porsche-O-Phile

http://www.freeze12.com/

I'm considering becoming a distributor for it. . .

AndyK

So I could buy another compressor and drier, and enough Freeze-12 - give it all to my mechanic and say "Do"?

Porsche-O-Phile

In theory, yes but I bet many of them won't. They won't put in a product they're not familiar with and can't make money off of (in most cases) so I'm just taking it down to be leak-tested and vaccummed out, then doing the charging myself (the quantity / pressure / temp. charts are all available for this product on the web site and they sell all the necessary hoses, gauges for monitoring, etc.)

There IS a list of freeze-12 shops / vendors too. Maybe there's one in your area? Nearest one to me is about a two-hour drive, hence why I'm considering doing it myself and becoming a distributor - lots of older r-12 based cars in SoCal. . .