schip43

Yeah if you have to open it anyway then I'd make the switch. But I read you need to pull and drain the compressor and flush the system.

Not to sure about the flushing deal? Flush it with what?Is flushing a DIY?

Bri Bro

It can be. You have to take the system apart to flush the hoses.
http://www.acsource.com/flushandflushequipment.aspx
Good clip on the subject.

CDH-CTT

You "should" flush the system anytime that you open it up.....and replace the receiver dryer as well....

schip43

Wow that was (no pun intened) cool!

C ANDERSON

Have 2 converted and 1 still with R12, the 134 cars cool as well as R12 except when idling for long period of time. If you convert to 134 change the expansion valve to one that is for a 134A system it is set to operate at the pressure settings that work better with 134A . and of course always change drier and flush the system with a good flush, put correct amount of oil. I find that most systems on all types of older cars converted people put to much oil and overcharge the system. 134 works best a little under charged than in a 12 system. Discoverd this years ago on an 86 turbo that had a leak, every time before it quit cooling it cooled the best a few days prior to leaking all the 134 out. I know they (the hellacious engineering young) say to charge with 134 at around 80% of what R12 called for and is pretty close.
If you watch the sight glass and stop just before all the bubbles are gone works good too.

I have a old school Porsche Tech friend that has argued with me about my theory for years and was down here in the 100 degree south with 98 % humidity , we were running errands around town in a 87 turbo converted and he made me turn the a/c down and now admits a 134A system will freeze you when done right.

Clifton

schip43

UH oh the expansion valve is that on the inside of the car?

C ANDERSON

Yes, But do not use the manual's for replacing. You can pull the blower assy out at the base of the windshield and change it easily, make sure to wrap it again with the insulation tape. good time to pressure flush the evaporator.

Clifton

Tedro951

A check locally (craigslist) shows much R12 in 1, 30 and 60 lb quantities, at prices around 15-20 a lb. As cheap or cheaper than 134a. Not sure what happened to 12oz cans of 134a for $7, but they are $12 or more, now.

C ANDERSON

I guess the demand for R12 is finally down, and now that summer is here as every summer 134 is up. come winter 134 will be $5.00. Got to love it. Back in the winter a old guy comes into the shop asking did we want to buy some freon , it was a full case of R12 , had $4.99 pice sticker on the cans gave him $8.00 per can, HOME RUN. He probably walked off saying them guys aint real smart.