heater control valve 64

[George D. #31849]

Can anyone tell me the purpose of the small tube that sits on top of a heater control valve for a 64/ac?

[Jimmy G.]

Re: heater control valve 64

Vacuum controled device. the small line controls if it is open or closed. Vac. to open, none and it will remain closed and no heat.

[Jack H.]

Re: heater control valve 64

Hum, the truth table is opposite that used in Shark era cars; are you sure.... With Shark valves, it's vac to CLOSE the cut-off valve and no vac to OPEN making the valve a normally open device. Suggests the design rationale was; in the event of failure how do we want to err? Let 'em freeze to death in the winter or sweat a little in the summer....

[Joe Pennington]

Re: heater control valve 64

According to the ST 34, page 13-44. " A significant difference is that in the Corvette Air Conditioning System there is no flow through the heater core until the COOL IN-HOT PULL knob is pulled out. This movement opens the vacuum switch on the air distributor assembly and allows vacuum to be applied to the water valve mounted in the engine compartment,opening the valve."

[Jack H.]

Thanks, Joe! *NM*