Looks like I will need a New A/C compressor for next spring, the question is this a DIY with ease or a pain in the )(&^(*&*&*&? Also should I stick with the R12 or go to the 134A????? All the hoses ect. are only a couple years old and all fine. Just the compressor is bad (original). Also if you have a list of all the necessary steps to sell me on a DIY, or just pay to have it done would be appreciated. Thanks!! John

 

There's a tech article in the Pelican archives on rebuilding your own a/c compressor. It sounds like a "do-able" DIY job. FWIW, I bought a rebuilt compressor, with clutch, from www.compressor-intl.com/ for less than $200.

Stick with R12.

Scott

 

You also ought to verify that you have "barrier lines" that do not leak freon. R12 is getting expensive. In the old days, it was chgeap and they allowed a slow seep to help keep the lines cool.

 

The new refrigerant is a lot less efficient at cooling so if your A/C is marginal on hot days already, like most air cooled Porsches, then stay with the R12 or do a serious evaporator upgrade.

 

R12 is expensive compared to R134 but is still relatively cheap. I just bought three 14oz cans of it on Ebay for $58. I believe this would be enough to refill the entire system. It would probably take one can a season to keep the system fully charged with non-barrier hoses.

Of course you need to get certified in order to buy R12. You can do this online for $15 by taking an open book test. Even an idiot like me passed after 30 minutes of study.

I plan on continuing to use R12 but will probably swap out the non-barrier hoses, out of respect for the ozone layer.

John Pavone

1987 - Carrera 17K miles

 

As I understand, in addition to being a rather expensive conversion R134 is designed to run at much higher internal pressures, which explains why it is less efficient when used in older R12 systems. My A/C specialist said it wasn't such a great idea to convert to R134 unless I also wanted to spend money on a compressor upgrade as well (which I decided to pass on).

There is, however, a petroleum-based alternative to conventional Freon (R12) referred to as R12A. It is compatible with existing R12 and designed to run at the lower pressure of R12 systems. I now have it in my SC and it works fine. Check around ... you should be able to find an A/C shop that can/will recharge with it. Apparently it's quite flammable, though, so get a shop to do the recharge.

As for the slow leak problem, my A/C specialist says the most common cause is non-use of the system. The lubricant in the system keeps the seals swollen and effective. When the A/C is not used for an extended period (like when the car is parked over the winter) the pump is not circulating the lubricant through the system and the seals shrink just enough to cause a slow leak. The remedy? Run the A/C every six weeks or so.

If your car is parked for the winter, this might present a minor problem. What I've been doing is picking a warmish winter day, letting the car run on the driveway with the A/C on for a half hour or so, then taking it for a short highway drive to warm the engine up fully. (This also charges the battery and scratches my driving itch at the same time!)