kstyer is right.My shop guy told me that unless you have to change major parts it's not worth doing it.The r134a just don't cool as well are the old stuff.

Just to add  to the thread - I did mine. Got an interdynamics kit, with all the info, etc to change it over.  Also had a good guage set for 134a.  On mine, it was a matter of drawing it down, charging it with the new oil (which is compatible with the old R-12 oil) and charging with 134a. Took 3 cans and I was good to go.

According to a licensed AC guy the only issue with the 134a swap is that the original oil for 134a was not compatible with the R12 oils and would attack the seals.  This is not supposed to be a problem with the new kits.  Napa, Pep boys, and just about any auto parts place sells the interdynamics kit for about 30-35 bucks.  So it isn't expensive.  Have used this same kit on 3 other cars with great results and have not had any problems after several AC seasons in NC.

Good Luck!

I still have not had time to work on the air yet, I'm still doing other things when I have time. I did make sure to seal all the air ducts and the HVAC case, did find the vent on the right side kick panel froze open and the seal bad. That would let hot air in when using the A/C, or cold air in when using the heater. Sure is a money pit, Like a boat! A boat is a hole in the water to dump money into! LOL!

You guys have a great day,

Xfire

My system is m-t, so I guess it's as good a time as any to go 134a. It gets hot and humid in STL area in the summer. I figure I'll need it.

When I bought my 82 last April, the AC didn't work and had not worked for at least eight years. I took it to a local garage where they check for leaks. Checked out OK so they replaced some hoses and valves, charged it up and I was cool all summer. Cost me about a buck fifty. We'll see how long it lasts. Hope to get it out of storage by April 1.

Ken couldn't have said it better. I've converted cars from r12 to 134a and when done properly there are no problems. The high side is up to 20% higher so a new compressor is needed. The less efficient cooling in a corvette would not be noticed. I converted my 91 Chevy 2500 Suburban with dual air a few years ago and it cools OK but not great like the new cars.  On each switch I replaced all the seals & flushed the complete system first and there was a lot of junk that came out.  So I would advise flushing the system. The sell a flush kit & it's not to much.

Alan

I am about ready to start doing the same thing in my '78 with the "pancake" compressor. I got the compressor from Advance Auto Parts for $139.00 plus a new receiver/ dryer with orfice tube for $44.00. I haven't gotten deep into the job yet, but on the surface, I do not see the original rec./ dryer. Once I get deeper into the job, the location may become obvious, but in case it's not.... Where does the receiver/ dryer mount?

Also... what is involved in flushing the system and how does one go about it. I have converted a '67 T-Bird over several years ago with cavernous underhood space and do not recall any problems other than significantly reduced efficiency. I had all new hoses made up for that job and have aded only 1 pound of R-134 in 6 years. I am going to try this one using the existing factory hoses, then replace as necessary if they fail a leak-down test..

Dave

Look in the right wheel well behind the front wheel.

Flushing requires a pressure source and a special flush fluid.  It is just forced/sprayed through the system components.  Don't flush the compresser or dryer.  You also don't want to flush the expansion valve or orifice, depending on which on you have.  Replace an orifice valve, only a couple of bucks.  Flush the expansion valve BACKWARDS, and out of the system.  Otherwise the crud in the inlet screen will clog the system.

kstyer38434.615775463

Ken,

I guess this special fluid is available at a parts house. How much is used in the process? Is it a one-pass deal?

I might be able to use an air/oil tank or a pump-up garden spray bottle as a pressure source.

Dave

Ken,

PS: Thanks... Ida never thunk to look inside the wheel well until a hose led me there!

Dave