Help! What is this line?
 

Can someone ID this line and where it should be connected?
1985 C10
Has AC
Looks to be some sort of AC vacuum control line or something.
Comes out of firewall and routed towards driver side.

Re: Help! What is this line?
 

Goes to the vacuum ball, from the ball it goes to manifold vacuum with a check valve. That vacuum lines goes inside to the heater and AC controller for the hvac doors. Should be going not too far from where it is at the moment. The ball mounts to the evap box. I can see the feed line to the ball just below your thumb with the check valve

Re: Help! What is this line?
 

Thank you!!

So if I were to get a new 'T' or something, Could I connect it somewhere in the red circle?

Re: Help! What is this line?
 

Where's your vacuum reservoir? That's where it's supposed to go, but yeah you can, but as soon as you shut the engine off nothing inside will operate vacuum wise

Re: Help! What is this line?
 

I will look today. I sold this truck a few years ago and just recently bought it back so I'll take a look.

Re: Help! What is this line?
 

if you dont use a vacuum reservoir, it will be like my truck...., full throttle, a/c goes to floor :) one day I will put a reservoir in there

Re: Help! What is this line?
 

Yep, there is that also that slipped from my mind

Re: Help! What is this line?
 

Bottom of a vacuum pot where the line goes. 2nd larger line goes to a manifold vacuum source. This one is next to the AC housing on the firewall. Some are spherical.

Re: Help! What is this line?
 

Pics should help

Re: Help! What is this line?
 

Thanks for everyone's help. I started digging around and found the T-connection where this is supposed to be hooked up to. Comes from the vacuum reservoir right behind my jack on Driver's side fender.