Components
It seems to have
1. one line that runs inside the truck, within a wiring harness loom.
2. one nipple on what I think is a diaphram valve to switch from inside to outside air(maybe).
3. one nipple on what I think is the air conditioner evaporator box.
4. A tee with a diaphram in the center of it. This is just laying loose, not connected to anything any longer. Cannot see any thing that it has inside of it, can see straight through it. But it could have rotted out. Not sure what this does either.
5. Two open ports (nipples) on the supply branch tree, mounted on the firewall.
This is all under the hood. The pieces were laying under the hood, but all were disconnected. I found this when replacing the vacuum pump on my dads old truck. He told me he could not remember when the Heater and AC quit working, but it had been a long time.
Do you know the function of the tee with the diaphram in it. Dad wanted to hook everything to the main tee, but that is obviously not how it was originally, since only two ports were hooked up, and I am sure that the little valve for switching the air flow would not work that way.
The main thing that I do not know is whether the valve hooks to the line going into the wireloom, and into the truck, or to the air conditioning evaportator looking black box. One of these must control the valve and the other must send vacuum inside to the HVAC control panel.
Neither does the truck have a vacuum ball, nor does it have vacuum boosted brakes. The brakes are hydraulic, off of the power steering pump.
Sorry for not including more info in my first posting, now it does seem appropriate.
Thanks, Dan.