The Stovebolt Site Forums The Shop Area Interiors 51 GMC heater controls

Hey guys,

I'm helping a friend restore his 51 GMC. We found new heater controls and are having a difficult time installing them. My question is, can anyone tell me where to mount the capillary tube? Does it drop into a heater duct?

Ok, I'll admit here that I was born in '73. What does this capillary tube do? How does it work? I have the factory manuals for this truck and they aare not telling me anything about these kinds of controls.

Any help here would be appreciated. Thanks

Dan

The capillary tube controls the heater valve.

It mounts in the open under the dash but I'm not sure how on an original truck. Mine is just propped up on a cable.

Dan,

The the tube usually has a little tab (with a hole in it) near the end. As cletis describes, instruction 8 and figure 99 in the 1951 Che Accessory Installation Manual indicate that a screw through that tab is attached to the "dash mat" (the interior firewall cover - near the middle-on-passenger-side, lower down on the mat/cover). You'll see from the diagram/picture that the excess length of the tube is coiled.

Here is a photo of the original location on a very original truck (49 Chevrolet), I have sold four deluxe heater set-ups this year and they all looked like this.
49 Chevrolet (1)
50 Chevrolet (1)
54 Chevrolet (1)
49 GMC (1)

https://www.flickr.com/photos/advance-design_parts_co/8129370372/in/album-72157631868452754/

Wow

Thanks guys for your fast response. The diagrams and pics are just what I needed

thanks again

Tim, thank you for posting that page. I went there to learn about the heater and found out how to mount my new to the truck defrost inlets. These projects would sure be more difficult without all the help we get from this forum.

Chuck

Realize this post is quite old, but does anyone have the pics or access to those from Brad Allen above? I see the instructions and diagrams from the Accessories Installation Manual, was just interested in the pic of an original install. Webshots link doesn't work and his album, while awesome, is like 168 pages

Thx,
Derek

Here you go, I also updated the webshots 🤬 link above in case this ever gets resurrected again.
https://www.flickr.com/photos/advance-design_parts_co/8129370372/in/album-72157631868452754/

Awesome Brad, thx much sir!

Derek

And thanks Brad Allen - I happened on this thread while searching for where that pesky tube was supposed to be mounted after it was left dangling in the air by the restorer before me on my old (but almost like new) 48 one ton. Your preservation of this old stuff, and keeping it available for sticklers like me, and apparently like Derek, is, well, it’s like priceless.

Dale

Ditto to what Dale said above.
Thanks Brad Allen.

Phillip

You are all welcome, I love these old trucks, now mine is complete I love researching the literature and information side of things, it is a fun hobby.