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Air Conditioning



I have a early 1976 vette and i'am getting ready to pull out the motor I'am wondering if a should replace my air conditioning parts why i have the motor out . Should i replace the evaporator and the poa/vir valve the air conditioning hasn't been used for about five years.
Going thru the same

The 1st question
Is the system still sealed?

2) Why did you stop using it?

3) You shouldn't have to replace the VIR assy just change the dryer bag & screen ( available aftermarket from 4 seasons ).

4) If the engines out ( meaning hood off) it would be a good time to replace the hose set that comes off the compressor. the fwd line ( high pressure ) can only be done with the hood off.

5) Pull a vacuume on the system and see where the leaks are ( I'm betting compressor shaft seal )

6) You mentioned changing the evaporator.... do you have a dent in yours?

the system leaked out freon because i had a hole in the hose as for the evaparator i have not taking it out yet
One of the classic "may as well as I am in there" situations. No easier time to do it then now. If the cost is not a major problem, go ahead and do it now.

I think you need to integrate this with the 1999 Vortex engine swap and try to update as much of it as possible. The POA system works great, but is bulky and takes up a ton of space. Same can be accomplished by custom lines with an orphis tube and updated to 134 Freon.
Holy Hose Freon Man!

Heres what you should do....unless you own all the proper tools SEND IT OUT & KEEP IT STOCK

The VIR MIGHT be salvagable but a full disassembly/ cleaning would be needed. All new hoses, the condenser & evaporator would need to be flushed and I would change out ALL o rings & schrader valves. I would exchange the compressor as well. Is the compressor one of the long style or the short fat one. There is a special long style compressor for corvettes ONLY.

Also now would be a good time to remove the blower motor and fish all the leaves, dead cat's etc. from the front of the evaporator.

The AC system is a big pain in the A** when the engine is in.. now is the perfect time to rework it. It will be about $800.00 in just parts to do it correctly and you MAY have to run it for a bit and change the dryer bag & screen twice just to get all the YUCK out of the system. AC systems (to work properly) have to be hospital surgical room clean internally.

If you send it in I'm guessing about 1150-1300. R-12 will also be a killer at about 45.00 a pound
( about 3 lbs per charge) Might want to consider

Get a warranty in writing, bringing this back from the dead will be costly, but worth it.

I'm not exactly sure, but isn't there something colder than R134A? I know that the 134 is good, but on some GM systems, it seems to be lacking in even the newer cars. Anyone know of anything else? --Bullitt

I use this in ALL my cars and ot works GREAT.

It's about a 2 deg warmer discharge then R-12

So the difference between 34 and 36 degree air


It will take a minute longer to cool the cabin. For
a 30.00 + dollar a pound... I'll sweat a few more seconds.


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