Captain_Slow

Got a little surprise today. I assumed my AC was still using R-12 because I had a shop confirm what I thought was an original R-12 high side fitting (and there are no decals anywhere stating it's been upgraded to R-134).

Then I pulled the blue cap off the low side and saw this..




It appears to be a 134 adapter. The larger blue cap should have been a tip off to a 134 adapter being there. I can't for certain recall the previous owner telling me the car had been converted to 134.

Why else would a 134 fitting be there if not to fill with 134?

The Deputy

No reason for it to be there...unless it was converted to R134a.

Depending on the year, the high side R134a fitting can be a bugger to install. The threaded portion on the R12 fitting is to short in some cases...at least it was for the two different adapter kits I bought. So, mine has a low side...but no high side adapter.

Brian.

Bertrand Daoust

Hey Jon,

This looks very much like a R-134A fitting.
See this thread, post #32.

https://rennlist.com/forums/928-foru...to-r134-3.html

Also, I think that on R12 systems, the low and high pressure service fittings are screw-type valves. On the R134a systems, the low and high side service fittings are quick-connect style fittings. The low pressure fitting is smaller than the high pressure fitting.

Found this info. here:

http://www.aa1car.com/library/ac_recharging.htm

Speedtoys

Ya..theres not enough room for the adaptor AND to use it easily.

Only places that have 134 only hardware would not be able to use the R12 fitting to manage your 134 system...I think...as most of the hoses/etc have fittings that can be either at the ends.

Captain_Slow

Thanks guys. Yeah, I have a vague memory of the previous owner saying he switched it over to 134. But I can't say for sure. Seeing the R12 high side fitting near the dryer made me second guess. Wish I'd pulled off the low side cover sooner.

Bertrand, thanks for the links.