C2 with C60 air cond vacuum question

[Randy Swartout]

On my 66 with factory air the heater is controlled by the vacuum actuated water shut off valve. The vacuum source is from the engine manifold tee. When the heater is off (temp dash plunger is pushed in)should there be a small vacuum leak in the line that feeds the vacuum switch assy? Disconnecting the hose from the manifold tee and sucking on it I can get a vacuum but it bleeds off within a few seconds. For those with AIM manual hose #22 C60 E5

In normal driving with ac off and heater off there would be this small vacuum leak.

Doesn't sound right to me but my friend with a 67 w/air says yes there is a small bleed hole in the vacuum switch assy.

[G B.]

Re: C2 with C60 air cond vacuum question

Yes, the leak is in the brass vacuum control switch on top of the heater box inside the firewall.

[Randy Swartout]

Re: C2 with C60 air cond vacuum question

Really!!

What is the function of this bleed hole? As I said before with dash heater plunger in (or out I just tested it in out position too) this bleed is directly connected to engine vacuum. I cannot blow thru the hose, but it won't hold vacuum.

If that's the way it is supposed to be great, I don't need more projects.
Thanks for the input.