82 K10 Heater Doors and Vacuum Lines

[9999]

82 K10 - 454 swapped block, ac not hooked up. Edlebrock intake

Heater core was leaking so was swapping in a new summit copper core.

Went to check door operation before putting the heater box up. Looks like there is no vaccum feed into the engine bay.

Defrost or the other vaccum door don’t operate. Cold/Heat works but that’s cable driven.

Also I have an extra vaccum line on the vaccum pod in the middle not the end. Some videos that pod shows a line in the center and one in the side. I don’t have a side one but do have a loose line.

Heater box has been pulled before, I can tell by the fasteners.

1. Can I just hook up the vaccum line under the hood to one on the intake?

2. Will leaving the extra vaccum line next to the pod up cause any issues? Anyone know what it goes to?

 

[75gmck25]

The vacuum ball under the hood has one side connected to engine vacuum, and the other side has a hose running to the heater controls. This provides vacuum to run the HVAC.
It will work without the ball, but the vacuum will then vary with engine speed and the controls will not work properly.

From the back of the heater controls there are about five thin vacuum lines running to the vacuum motors. The original lines have a color stripe on each one, and at the vacuum motor end they have a rubber/silicone piece to plug into the vacuum motor. As you move the heater control slider it will close or open connections to each vacuum line, and that changes air flow.

I would have to get out the schematic to get an accurate list of the vacuum motors, and it may be a little different for some years.
- The motor in your picture looks like the cowl vent motor that you access under the hood. The line to this motor has a vacuum T and it runs this motor and the one in the passenger kick panel. When you put the truck in max A/C it opens the kick panel vent to recirculate cab air, and closes rhe cowl vent to shut off outside air.
- the motor on the back of the plenum near the firewall is the one with two vacuum connections. I believe that gives it the ability to be completely closed, completely open, or at the half- way position.

 

[Juggernaut]

The hose you're holding goes to a port on the inside of that vacuum solenoid just below your hand. You can see the other end of that hose is sticking out of the heater box just to the left of the solenoid.

 

[9999]

We pulled the vacuum ball from under the hood awhile back. It didn’t have any lines hooked to it at the time. I’ll dig it out of the garage and get it hooked up.

Thanks for the help everyone.

 

[9999]

75GM - Found the vaccum ball and going to run some new lines and patches to hook it back up.

Juggernaut - That’s exactly the line and where it goes. I was expecting it to plug into somewhere and don’t know how I missed that part of the line when looking it over before.

 

[9999]

Does anyone know if I need a check valve between the vaccum ball and the line I tie into the intake manifold?

 

[gmbellew]

Does anyone know if I need a check valve between the vaccum ball and the line I tie into the intake manifold?

yes. check valve after the manifold before the T where the line splits.

 

[9999]

I got everything hooked back up and tested all the doors before I put the heater box back in.

Got a check valve coming from Amazon, so should be good after that.