What is this vacuum line?

[ncc]

Hi all,

I was working on the truck recently when I noticed a vacuum connector with about six inches of tube laying on my crossmember. I need to know where the connector attaches to.

The tube is a gray vacuum line about 1/8" in diameter and runs along side a similar black line under the washer fluid reservoir and back under the blower motor. It melted apart probably after lying against the exhaust manifold. The black line connects to another line behind the passenger-side headlight, but I can't find anything for the grey line.

So...anyone know where it connects to?

Thanks!

Jeremy

 

[Turdle]

That line goes to the heater bypass valve, I think.
There is a black plastic part on the heater core hose, next to firewall on passennger side--does it have a grey vacuum line to it?

 

[ncc]

I'll check. It's getting dark here now and pretty cold to boot so it'll have to wait until tomorrow.

What does the heater bypass valve do?

Thank you for the reply!

Jeremy

 

[410Fortune]

it bypasses the heater core with hot coolant, heater on = flows through heater core, heater not on, does not flow through heater core.

Your vacuum line either goes tot eh heater bypass valve OR to the firewall and into the cab, is your heater working? Does it work on hot and cold?

 

[ncc]

is your heater working? Does it work on hot and cold?

Yup. Heater works. Although I'm in the middle of solving the typical high and off speeds only on the blower motor. But I doubt that's related.

Thanks again!

Jeremy