Good afternoon all, I was looking for some advice for getting A/C up and going in my 1976 Corvette. It currently has all of the factory components installed and air blows when I turn the controls on, but it is very weak and it is warm. When I had my center gauge cluster out to replace some bulbs, I noticed that the center distribution ducting has separated at the seams at many points and some of the under dash ducting has cracked and crumbled as well. The more research I did, the consensus seemed to be that unless I was really wanting to keep the car 100% original it would probably be more cost effective and less frustrating to just put in an aftermarket system and be done with it. Looking at prices for some of these original parts I can see why, haha! While searching I came across two Vintage Air kits, one that is just the evaporator kit (looks like it takes care of everything inside the car) and the other is the full kit with compressor, condenser, and everything in the engine bay. My question is this; since I still have all of my original components in the engine bay and they look to be in decent condition, would it be ok to get the evaporator kit and attach up my factory parts? Naturally I would take the condenser out and have it pressure tested and get the compressor checked out as well, but if those come back with a clean bill of health would I be ok to go that route? Maybe with a VIR eliminator kit thrown in as well? Or would it be best to get the complete kit and be done with it?

 

Unless you have the proper ac diagnostic equipment, I would first go to an ac repair shop to determine what is wrong with the system and then decide from there based on their repair cost.

 

Sound advice. MANY times, the only fault with old A/C systems is that they are low on refrigerant. And, there are several other faults that are easily repaired....for much less money that replacing it with a new system.

 

My early 77 had an HVAC system very similar to your 76. I tried to install a VIR eliminator while the engine was out. I gave it up as a bad job and went with a Vintage Air system (lots of adaption, their kits only go up to 76 - search for my write -up). If you're going to replace your system, I would, first go with VA, and second replace the 40+ year old crap you have under the hood. Modern systems are going to go with R134a. Your original hoses were designed for R12 and are permeable to R134a. Your condenser was designed for R12. To properly extract heat from R134a, you need a multipath condenser for the system to cool properly. Your existing compressor is either an A6 or an R4. In my experience R4's lack durability with R134a and the necessary lubricant change. I went with the lighter and more efficient Sanden 508.

To summarize, much of the Vintage Air's cooling power comes from those "parts under the hood". If you want an HVAC system that will perform properly under the worst conditions, spend the money and replace the parts under the hood. You'll be happier in the long run.

 

No, I do not have any diagnostic equipment for A/C. I have a shop that would do it, but when we started going over the myriad of small issues they thought it might just be easier to start fresh with a new system. They said it's really easy to start nickel and diming me to death with all the small things.

That's pretty much what I figured. I'm going to try and fix some of the small things with my factory system on my own and take it to my A/C shop to see if it will work when refilled. If not, I'll bit the bullet and snag the Vintage Air setup. All I know is that it's waaaaay too dang hot in Texas for no A/C, haha!

 

Have you actually had someone pull a vacuum on it? My 72 went years w/o Ac, one day I pulled a vacuum just for fun, ended up it was just a cheap Schrader valve leaking. A vacuum will tell you how serious of a leak you will have.