ffas23

I have owned my '73 Coupe 33 years now. Over the years I needed to add a can of R-12 Freon on occasion. Right now it is a little low but is holding a charge. Went to add a can today and lost my special R-12 (90 degree) Adapter Fitting I had for years to fit the low side of the system under the Passenger Fender where the factory fitting is located so close to the Evaporator housing. Does anyone know if any of the Corvette Vendors carry this adapter either brass or even possibly in a flexible hose to connect to my standard set of R-12 Gauges? Just curious as I have been doing a few searches on my own and so far have come up blank except for a few assortments I see for sale online. I am sure others here had to deal with the same problem over the years and needed to locate that special adapter.

GRipp 73

Surprised no one has chimed in on this one for you yet. I have not done any of this work yet, but the A/C components on my '73 are something I want to look into this winter as part of my projects. I have everything in my engine bay for AC, but can't seem to get it to turn on yet. I will figure it out, but there are other projects higher on my list right now.

So are you talking about something like this from Amazon?

ffas23

I am surprised also. I found an assortment on Ebay and ordered it Monday. Was hoping a Corvette Part Vendor on the forum would of offered the exact one needed to fit the Low Side on a C3. I believe I loaned mine out to someone now that I think of it and they never gave it back. Got it through my auto parts store many years ago but I am retired now and lost my source. The kit on Amazon that you show is exactly like the one I purchased on Ebay. Hopefully one of the 90 degree fittings will be the one I am looking for. It's a real pain to get in there under the fender to service it.

ffas23

If all your components are there and in good shape and connected you will next need to get yourself a set of R-12 Gauges and hook up a A/C Vacuum Pump to the low side fitting. You will then need to draw down the system. Once it is drawn all the way down you can then add freon if you can even find R-12 Freon somewhere or will need to do a conversion to R134 which will probably really be a pain being you will have to put Adapters over the stock fittings and as I said above there is not much room to get to the low side fitting to begin with. R134 Gauges have Snap on Fittings installed on the end of their hoses on the High and Low side. You might not be able to even get the Low Side Hose on the Low Side line do to no room because of the Evaporator housing. Best bet when doing this if the system was ever opened and is completely absent of freon is to replace the dryer before doing anything and then immediately vacuum the system. You can still get away with using R12 Gauges if you can locate some Freeze 12 Product. They discontinued making it recently but I believe you can still find some Available out there although it is not a real R12 freon but it was made years ago as a replacement and it works fine. The 12oz can is even the same size can that the real R12 comes in.

ffas23

Didn't receive my assortment of 90 degree R-12 adapter fittings as of yet but Wednesday afternoon came across a extra Refrigerant hose to fit a set of R-12 A/C Gauges in my barn. Forgot I purchased it years ago. It had a bent 90 degree fitting on the fill end of the hose. Didn't fit in the location of where the low side A/C fill point is located on my '73 so I did a little persuading to make it work. I took a special brake line bender tool that I have and mounted the manual tool in a Vise. The line is brass and not as easily bendable like a steel brake line is so with the use of a ball pein hammer I slowing tapped the end to bend the position of the fitting to have room to easily screw the fitting on to the fill end above the A/C dryer. After putting it back in the Vise 3 times I finally made that extra hose into my new A/C fill adapter for my C3. Glad to report my '73 Coupe A/C system is Ice Cold once again. This should last me a good 6-7 years before I will need to add freon again based on past experience owning this car so long as it sits more then it is ever driven in my small Classic Car Collection along with my two other Vettes my C2 and my C5.

GRipp 73

Awesome. Thanks for the notes and the follow up. Most on here don't report the "good" news after a solution has been found. How about a picture or two of your setup now?

ffas23

Nothing special about it. Just bent a factory R-12 Hose for a set of Gauges. Funny I did the job on Wednesday and my R-12 assortment of 90 degree fittings came in the mail this afternoon. I am sure they won't go to waste. Not loaning out anymore of my tools from now on. You would think some of us would learn from mistakes in the past as it has happened before.

ffas23

GRipp 73 did you ever check to see if you have Freon in your system? If not take the Cap off of the low side of your A/C system and push down on the needle for a second. If you have Freon in the system and the A/C doesn't come on you will see mounted near the top of the Evaporator Housing a Electrical Connection with a Thermal Limiter fuse plugged into it. If it is defective your compressor will not turn on. It is sort of a safe guard to shut down the system if you run too low on Freon which is a good thing to protect your compressor from burning out.

GRipp 73

Thanks ffas23. Yea, I did that already and heard a quick hiss. So it seems to still be holding something of a charge. I haven't put any gauges on it yet to see how much (or little) of a charge there is. There seems to be some sort of "cap" or cover that I am missing on one of my electrical connections, but like I say, fixing the AC is going to be one of my next winter projects. If I get a chance, I will take a picture this weekend to show where I seem to be missing this cap.

But right now, the clutch is not engaging on the compressor. It spins freely and the belt is hooked up, just doesn't "click" and lock in. Maybe it is the Thermal Limiter fuse like you mention and it is trying to protect itself.

I just picked this beast up about a year ago, and have a lot of receipts for the car, and from what I can tell, the AC was last serviced in 1991!

ffas23

Being low on Freon most A/C Compressors today will not come on but with your system like I said above it has a Thermal Limiter Fuse. I use to sell them by the ton in my Auto Parts Business back in the day. I still have a bunch of them on the shelf outside in my barn brand new in boxes. I believe there is 2 or 3 prongs on each of them where they connect. Its been so long I will have to take a look at one tomorrow next time I am out there. They blow out pretty easily if the system is not right. Hopefully you still have some Freon in the system. If so you may just get away with giving it a charge. Systems that have been open or without Freon for too long will kill the dryer and if using a bad dryer even filled with new Freon your A/C system will not work right. I have no idea who even would carry a replacement today for the '73 since I have been out of the business and retired. If I were you I wouldn't wait to Winter to deal with the A/C system. If it needs Freon I would deal with it before time. Don't know where you are located but you need to have nice weather to do a A/C charge unless you have a heated garage.