All,

My Heater Hose Shutoff valve started leaking, so I replaced it. The vacuum hose connected to it does not have any vacuum to it, so it does not close valve, preventing coolant to the heater core. This of course, makes it blazing hot in cabin.

The vacuum line goes to a 3 line "plug" attached to the firewall in center of engine bay. Why does this not have vacuum? I tried changing the selector in the cab, trying to get vacuum to this line, but no luck.

Thanks for your help!

 

That line only has vacuum if your dash dial is on Max A/C and the temperature dial is turned all the way to the cold side.

 

that seems a little odd. hot coolant is sent to heater core the rest of the time?!

 

Yes it is.