HVAC Vacuum Line 2000 F150 4.2
 

Hey all, hope everyone is doing well.

Just got done with and intake, steel heater hose nipples and IMRC repairs. Worked out great but man my back and legs are feeling it leaning over that thing so long.

Anyway, like I said everything worked great but the AC vents were stuck on Defrost so I figured I messed up a vacuum hose. I checked and it all looked fine but right where the hard plastic line goes through the grommet in the firewall there was a crack. I pulled on it to see if I could get the inner part to extend a bit and maybe repair it but the rest just came out. Maybe an inch or two.

So I felt around behind the glove box but could not feel where the line came through. I'm wondering if anyone else has had this problem and was happy with their solution. My next step is to pull out the air bag and see if I can do something behind it perhaps. I'm betting the rest of the line is hanging there near the inside part of the firewall.

Anyway, have a great holiday weekend folks!

I would think it goes to your control panel..Just run a new line.

did you ever figure this out? What does that small black vac hose connecting to the firewall connect to under the hood by the battery?

The hard line coming from the firewall (originally from the heat/air controls in the dash, goes to the T type blue and cream vacuum check valve between the battery and the firewall. See pictures above. it is the check valve on the right of the picture, the one closest to the engine. That T should go into the bank of vacuum splits below, then back to the vacuum storage canister behind the battery, a very common leak point.