scfd471

Good Day
I have an '80 L82, the car is very original with 30k miles on it.
Ive owned it for about 6 months now (first Corvette), when I bought it the AC had been converted to 134-A, the AC didn't blow cold, but "cool", I checked pressures and added a little 134...no help.

A was able to score about 20 lbs of R-12 (which I'm told is a way better refrigerant) So I got a new accumulator, and orifice tube; mineral oil added, the system was vacuumed down, and recharged with 3.75 Lbs of R-12.
All pressures are good, the high side line from the compressor is warm, when it hits the orifice tube, turns cold. lines coning in and out of the evaporator are cold...the accumulator is nice and "sweaty".
So all things look like the system is working as it should, but the air is still just "cool" its a little better when your moving, but not much.

I noticed there is no heat shield on the evaporator box, and its very close to the exhaust manifold.
Is this "just how these cars are"?
I don't want to just start throwing money and parts at it (condenser, lines compressor, etc.)
Has anyone visited this issue, or have any suggestions?

Thank you
Dana

speedreed8

You need to make sure the vacuum controlled water valve for the heater core is closed. I installed a manual shutoff valve in line with the factory valve. Your heater may be slightly on because of this valve leaking. It should be in the heater hose line below the evaporator box.

DUB

It depends on what setting you are putting the A/C control at when testing and if you are driving it or it is sitting still.

There was no type of radiant thermal barrier material applied on the evaporator case from the factory.

I have seen leaves and stuff block the front face of the evaporator core many times and effect how it cools the cabin.

DUB

terry82

I put a heat shield on mine

Greg

I agree with DUB. I've pulled the core cover on every single A/C car I've had and every single one of them has a build up of leaves, twigs, hair and crud, ESPECIALLY the Corvettes. They tend to be finicky so they need every bit of help you can give them. The cover is off in less than 15 minutes, compressed air, rinse with a garden hose then reseal it with the flat putty type sealant that comes on a roll. Every hardware store has it in their weatherstrip/window seal section. It forms easily to the box and gives you a new good seal, replacing the old hard stuff. Just one more thing that helps. Again, I've done this to all my Corvettes, I use 134, I live in the California desert where we hit triple digits pretty regularly and my cars are cool inside.

Rotonda

Dana,

When I removed the system from my 77 to replace it with a Vintage Air system, the portion of the evaporator box nearest the exhaust manifolds was VERY fragile and brittle. I easily put my finger through it. This is an indication of the amount of heat it was exposed to, so insulating it can't hurt.

All of the other comments have merit, but the biggest improvement you can make is to increase the volume of cool air by replacing the pathetic O.E. squirrel cage fan with one from a C4. You can use your original fan motor. The C4 fan is plastic, slightly longer and has MANY more blades. It moves much more air, and was the best mod I made before replacing the entire O.E. system. Search the Forum for more info.

~Stingray

Just out of curiosity, what are you doing driving around with the AC on anyway. Take those tops off and enjoy the sun!!

Street Rat

So did I...

scfd471

Thanks for all the suggestions & feedback...will try all of it!

kanvasman

Ditto the changeout of the fan cage with one from a c4. You will have to make an adapter but do s search here and you can see how it works. I would also make sure you have aa good
ground for the fan. One last suggestion would be to throw a thermometer into the vents with the ac blowing. That will give you an idea of how cold things really are. Goodluck

Dennis Tapp

what should the thermometer read if working right?

kanvasman

My rule of thumb is if I can get it down about 20 degrees less than the outside air, that is about as good as you can go. Sometimes more, but that is my benchmark. Good Luck