Hey everyone, new to this forum. Bought a 92 F150 XLT few weeks ago. 143k miles, not bad for what I got it for. Has some frame rust, going to be cleaning that up and painting the frame with por-15 soon. anyways, the **** inside that changes the air flow from defrost, vents, etc does not work. It is stuck on the defrost vents. Also, the one that controls inside/outside air doesn't work either. Both of the vacuum lines are broken, I think. Anyways, where can I get these parts, and is it possible to do it myself? I don't have many tools but I'm pretty handy. Any recommendations help, I think this is pretty common. The line on the passenger side, very top corner (closest to windshield) there's a little vacuum powered servo with the white line broken and it looks like the line goes in behind the firewall, then there is another line right on top of the manifold. I'll take some pictures tomorrow. Thanks!

 

I would just run new lines. Are they the colored vinyl lines? Those love to get brittle and break. I wouldn't be afraid to just replace with generic rubber hose, but you want to be sure that it won't collapse under vacuum.

I thought this thread was going to be about the Secondary Air Diverter (thermactor/smog pump system)...

 

The HVAC system defaults to the defrost position with no vacuum applied:


The infamous brittle white vacuum line for the recirculation door is another problem area, as you have found out.


Some photos and info in this thread: https://www.ford-trucks.com/forums/1...rost-only.html