Can anyone suggest where I might go to find a kit that replaces the existing A/C shrader valves and fittings on my 1971 Mopar? I want to convert from R12 to R134A. I have all the other stuff but can't find a kit for just the shrader valve conversion. I saw some kits on Ebay but I don't know the thread sized that I need.
Thanks

Get them at the local parts store. That way if you guess wrong you can return them and get the right ones. They run around $15 a set.

When converting to 134a, it's best to flush the complete sytem except the compressor. Then install a new 134a dryer and replace all O-rings with ones compatible with 134a. Recharge 134a at only ~80% of the volume spec for R12.

You also need to drain any oil left in the compressor and replace it with an R-134a compatible refrigerant oil too...

Some also want you to change all the hoses to barrier (liner) type, since R-134a leaks from the old hoses at a higher rate than R-12. You're already going to have both ends disconnected to change the o-rings anyway...

From what I was told by Classic Air you need to remove the POA valve and put in some type of limit switch.
Ron

I converted my 92 D250 to R134. It doesn't cool as well as it did with R12.
The work was done nearly 15 years ago and I've been all over it numerous times. It just doesn't do the job as well.

I thought about going to 134 on the Imperial but the 12 cools much better than 134 in my truck. I have no interest in messing with that.

A 92 doesn't have an RV2 compressor or the same expansion valve.

You are probably running an R12 expansion valve and need an R134 one to make it work right.

My 87 Diplomat I converted to R134 and it cooled ok, not as good as R12 though. Wife's 96 Neon came with R134 and would make your joints ache it got so cold. Noticed that both used what appeared to be the same, physically anyway, expansion valve, so I put a Neon one in my Diplomat and it really helped. You may consider that for the truck. I eyeballed the pictures at RockAuto and they look similar enough to maybe swap.

Thanks guys!

I've been down that road. Throwing parts at it over the years hasn't fixed it. It cools well enough. I had the fan on high and was comfortable when driving through Needles on a 117 degree day.
The truck cooled better with 12.

Systems designed for 134 work great with it. For some reason the conversions just don't quite seem to do as well.

It depends in part on the condenser that came from the factory... When the compressor seal went on my '84 F-150, since I had to put a new compressor and receiver dryer on it anyway, I converted it to R-134a.

I stay cool and comfortable in southern MO heat/humidity (frequently 90/90 in August)... the old Ford has a huge condenser and lots of airflow through it.

For those who don't want to convert, a mix of propane/butane (available commercially as "Duracool 12a") is a drop-in replacement for R-12, although illegal in some states. No penguin-unfriendly ozone depleting potential
and very cheap to make, so Dupont-funded lobbyists did their best to suppress it.

Freeze 12 works well also.

So does propane if you want to get down to it.

I added the complete factory AC system from an '87 to my '84 pickup and converted to r134 at that time. The system worked but not all that well. When the compressor died years later a technician friend of mine advised that the system would work much better if I changed to a condenser that was designed for r134. I did. The AC system now works MUCH better.

I have my license so I can buy R12 for my 65 Cuda, assuming I ever put it back together. Problem is finding somewhere to buy it anymore.

Yep, I got my Part 609 card too, about 20 years ago

If you can find it, R-406a works even better and is a drop-in replacement for R-12. Still has 0.05 (compared to R-12) of the penguin-depleting potential, so it may have been phased out too.

Been about that long since I got mine as well. At the rate the Cuda is progressing those cans will rust thru and vent before I get the car back on the road, last time was 1998.

I know the feeling. I got the block for my Dart in 1997 and just fired up the engine for the first time this fall!

Let me know, I'll probably still have 'em.

All my vehicles are either 134a or have been (properly) converted to it, except my '65 F-350 to which I added Classic Air back in '00. I've only had to put one can of R-406a in it since then, and I have several of them in reserve!

I think in Orange County it's illegal for you to even take that picture

A Moparts member was kind enough to donate several cans of R12 to the Imperial when I got it running.

We still have a functioning R12 machine at work so I was able to recover it when I had to pull the condenser.