C2 Factory Air Problem Solved

[Bruce Boatner]

At the risk of looking foolish, I am passing on the solution to problem I had with my 1964 coupe blowing warm vs. cold air through the a/c system. Hopefully, this may help someone else out there save some time and aggravation. Turned out that the source of the problem was the heater valve leaking into the heater core thus warming the cold air before it exited the vents. It's amazing how much of a difference it made when I clamped off the heater hose. (The temperature regulating method on the factory a/c system is not very efficient in that the only way to reduce the coolness of the air is to switch off the system completely or introduce warm air through the heater.)

Hopefully, installing a new heater valve will properly fix the problem. For now, I have a bright orange hose crimping tool on the heater hose. Would I lose judging points for this?

[Tracy C.]

Re: C2 Factory Air Problem Solved

Well Bruce,

Great to hear your problem is solved...As for lost of judging points for the crimping tool, I'd say you will recieve full judging points because it is chevy orange.

The judges really deduct down on the blue ones...
tc

[Randy S.]

Re: C2 Factory Air Problem Solved

Interesting. By leaking I assume you mean the water (heater) shut off valve was allowing hot water to pass to the heater core when heater was in off position. By applying a vacuum to the shut off valve I can hear the diaphram move so I assume it is OK. Doesn't necessarily mean it is closing totally.

On a recent 65 deg day I took my 66 roadster out for some spring exercise and noticed that with both AC and heater off I was getting 85-90 deg temp in the ac outlet. Is this engine heat soaking in? How would you check to determine that the heater shut valve is closing totally? I know it opens on demand because I have good heat and defroster temps. With AC only I am getting in the high 40's F (R134 system)

Randy

[Bruce Boatner]

Re: C2 Factory Air Problem Solved

Randy,

Sounds like you the same issue I have. My heater control also produced MORE heat on demand. I was also getting heat WITHOUT demand presumably due to water leaking past the shut valve while in the "closed" position as you described.

My suggestion would be to get a pair of crimping pliers ($7 from the local Auto Zone). Crimp off the small section of hose between the shut off valve and the firewall/heater core and see what happens. If you notice a difference I cannot think of anything other than a leaky valve as the culprit. Having said this, I did notice some warm air in the vents after the car hit the 180+ range on a recent 80+ day here in Houston; however, I am attributing this to a litte water leaking past the crimpers while under higher pressure from the heat. I'm going to replace the shut off valve and hope for the best.

Hope this helps your lower your a/c temperature. FYI, In my case the air temperature with the a/c on was closer to 70's than 40's.

Good luck!

Bruce

[Jim T.]

Re: C2 Factory Air Problem Solved

Randy don't know the specifics of your 66's air conditioning heating system, however with my 70 the only time vacuum is applied to the water shut off valve is when I select MAX-cooling. During the other positions, even off, the hot engine coolant water circulates through the heater core.