first thing i did was take advice of a few forum
members when they said swap out your control valve
its probably bad.
i hooked up the mighty vac to the original valve and found that
it would hold no vacuum so there was an obvious hole in the
diaphragm.
picked up the replacement valve and swapped it out for the
new one.

second thing i did was to pull the glove box liner out so i
could access the water shut off valve switch to adjust the cable.
i found it easier to remove the liner and adjust it at the switch itself rather than remove the console side plates to get to the temp control cable.
i found that with the temp control selector to the cold position it was not shutting this valve all the way off as its supposed to according to the assembly manual.
on mine i had enough adjustment behind the glove box to get this
valve to shut all the way when its in the coldest position.

after replacing the valve and adjusting the cable i started the car and let it warm up to operating temperature.
i stuck my hand down to the floor to find no more hot air coming out of the ducts.
the real test will come with a drive but i can tell you that at idle i always had hot air blowing and now its gone.

 

Congradulations!
Bernie

 

 

 

I did the ball valve in the heater hose trick last weekend and it didn't really make much difference, if any. I still get warm-hot air coming through the ducts, even when the system is off. The air must be blowing into the system from the right side cowl area under the blower motor. Thats my only guess but at full operating temp going down the road, the air coming out of the ducts is about 90-95*.

AC would be pointless at this time. Ironically I don't feel much heat coming through the firewall but the plastic air ducts are almost too hot to touch. I called a local vette shop and they said between $2-3k to get the AC fully restored and working properly.


I'll just keep sweating my ***** off, Thank you very much.

 

I disconnected the hoses altogether and ran the hose from the pump to the intake manifold. If you have only one ball valve the water is still going to heat up so what.. In florida I don't need the heat so bypassing it was the answer

 

The Temp Control Cable controls the "Blend Door", which allows for all Heat, or no Heat/Cold if AC'd, or any combination etc. If this doesn't shut off the Heat you'll bake, so check it's adjustment.

Another thing to look at are the Firewall Seals for the Heater/Evap Box, plus the Heater Box Seals where the Heater Hoses connect to the Heater Core.

Doug

 

Just a quick question: I should have replaced the metal vacuum piece that op/cl the doors behind each front fender (for venting outside air into the cockpit) while I had the entire front-end replaced.
Now it seems these doors aren't operating, can I access them from inside?
Thanks for any help,
Mark

 

I think so, you get to them from behind the kick panels

 

Re-doing the factory a/c is project well within the abilities of most people on this forum. I just did it as an after thought of changing the radiator core even though the a/c was working great. I thought, "There'll never be an easier time"--with the radiator and core out. Individually, the parts are pretty easy to replace--just think of it as one project at a time instead of the whole business at once.

Here's a price list of what NEW GM parts can be had for; I'm sure you can find cheaper prices on Ebay, etc. And, the compressor can be bought rebuilt instead of new.

Parts:
Condenser Coil 200
Compressor 250
Refrigerant Rubber line set 075
Evaporator Coil 175
Heater Core (might as well) 060
Heater Hoses 050
Water Valve 020
Case/Vent Seals 035
VIR or POA Unit 150
Line seals/orings 035
Misc Paint/Materials 050
Refrigerant 050

Existing refrigerant hard lines can be polished with scotchbrite and painted with clear engine paint--they'll function and lok like new.

Tools: (cheaper to buy these items then get a shop to vac & charge it)
Vacuum Pump 175
Gauge Set 100

So, $1425 for an all new system plus the equipment to work on it more later.

I could do this job on a long day. So, if you give yourself a week--it'll be a straight forward job.

 

even with side pipes it was hot? Chaning from manifolds to headers seemed to cool down my floorboards. Even with 2.5" chambered rear-exit exhaust.

Down here in FL we never need heat so I bypassed my heater core completely.

 

Should I have installed 2 ball valves? I thought we only installed one on the hose coming from the intake manifold.?

Photovette, its too bad you're not in houston, I would let you do it in a day... Thanks for the advice though.


I did check the cable on the Hot/cold flapper valve on the main air duct and it seems to be closing off completely from what I can tell. Maybe not though, that would make sense for the hot air still coming out.

 

I bet you have air leaks in the passenger side intake. After all these years, the sealant dries out and flakes off. Check out the archives here and the wiki page at Corvette FAQ for tips to reduce cabin heat.

 

Excellent news. Congrats!

 

ajrothm,

I had and have some of these problems. However the car is getting better with each year. One thing i did that make a difference was the fresh air duct or heat duct at the passengers foot. Remove the kick plate and take it out. I them used some sealant and attempted to seal the seams behind it. Its hard to get your arm in there! I then got the rebuild seal kit from Doc Rebuild and took the flapper apart and put on a new seal. It seems to work better. However as you noted there's heat coming out of my AC ducts too! I too got a $2,000 price to restore my AC system, which I tought was high as I can do it myself. But if the for the prices of the parts etc ... I wonder. That was at a classic car place that specializes in AC, Klassic Kool I think ... If and or when I remove the engine, I'll put a better condenser in and restore the system. One thing that is killing me is that I need to install that foam collar up under the transmission. I'll do that when I put the 5 speed it!

Good luck with your efforts.. Oh and the double dynomat job I did made a BIG difference!

Magadon ... wants to do a drive down to Galveston some time. We need to get some vette heads from the forum for a run at least to Kemah ... Hooters maybe?

carbster

 

Thanks Carbster..

BTW, not to thread jack but tomorrow night we are getting some vettes together to cruise to the Niffteefiftees car cruise on 249/Spring cypress. THey have about 300+ cars every saturday night. If you wanna go or meet us up there, let me know. We will be taking the BW8 all the way around to 249. We are coming from League city its a good cruise night. 3 of us are going so far and anyone is welcome to roll with us.

 

OH and I am down for a cruise, whenever, where ever. KEmah, galv, and definetly hooters. Hit me up anytime. You ever come to the car cruise at the Home Depot/Chick Fila in League City/Kemah on sat nights??? Pretty good turnout every weekend. Lots of vettes.

 

Same problem here (we get your Houston weather up here in NY during the summer)..what I did, I put a hot water PVC turn off valve in on the inward flow hose, stopping any hot water from entering the heater core, then went to Radio Shack, got a couple of rolls of coax seal, sealed around the passenger vent door and plugged and removed the vacuum line to the vent door canister, then, cut a piece of 2 inch styrofoam to fit the vent door hole and snuggly pushed the piece in (had to remove the canister and the connecting arm, then put the canister back in, not connecting the arm after sealing), then sealed that around the edges of the styrofoam...
It's been in the 90's last couple weeks and it's a pleasure to drive again...even with the A/C not working and both windows down...last summer, it was UNBEARABLE in the 70's...
That's my story...

 

I was in your neck of the woods today sailing. We came back early as the wind died on us. I'll try to find you guys at the show tonight. My cell is 281-384-8854.

249/Spring Cypress? I'll just look for all of the cars!

Carbster.....

I have not been to any car show as I really don't know what's on and where.