Looking for some help with venting.

[HO455]

I picked up one of the later year Suburban fuel tank vent tubes for my 67. I want to get away from the non-vented fuel caps that always seem to leak on hard left hand turns with more than 1/2 a tank of fuel.

One of the things I need is measurements as to where the factory installed them. I'd hate to drill a hole and find something in the way inside the rear quarter panel. The measurement can be inside the cab or underneath where the lines exit or in a perfect world both.

My other dilemma is identifying the 3 lines. At some point in the past I found a thread identifying the 3 lines in the bottom of the tube but dang me if I can find it now.

If memory serves me one line ends to near the top of the tube. One line ends midway up the tube and the last one ends at the very bottom of the tube.
I'm sure the one at the top of the tube would go to the vent canister
The other two I think go back to the fuel tank?

I really only need the one at the top the canister and one on the bottom of the tube. I could fill the tube with water to identify the heights of the lines inside the tube but, I'm hoping someone here will have the information I need and save me some steps.

The factory chassis manual shows the bottom line ( Line to the farthest right in photo) going to the canister but no information about if that is the highest line in the tube.

Thanks in advance.

[richard2717]

If no one else pipes in before then, I can get some pics and measurements off of the 72 I have sitting here in the morning

[pontiacvince]

I changed over to a 40gal. tank and had the 2 vent lines added to the tank to use this same system. I used that same diagram to hook my lines back up.
Putting a tape measure in mine, there is a small upward bend at the rear I measured from. It's 9 1/8" to the first hole from the rear, and 2 1/8" from the outside to the center of the first hole.

[richard2717]

Here is what I have from this morning. I would need to pull the covers off if you need the size of the holes in the quarter panel.

[HO455]

Thank you very much gentlemen! Just what I needed.
Richard no need to pull things apart. The plate I have has the hole outline etched in rust on the back side.
Not all rust is bad.

[pontiacvince]

HO455, Now is the time to sound deaden and insulate if you are going to...I used 3" house insulation between my side panels and the sound deadener...

[richard2717]

Originally Posted by pontiacvince

HO455, Now is the time to sound deaden and insulate if you are going to...I used 3" house insulation between my side panels and the sound deadener...

Be careful with house insulation. One of the suburbans I parted out was loaded with it and it had a leak in one of the windows. The insulation was totally soaked and had started rotting stuff from the inside out.

[HO455]

Originally Posted by pontiacvince

HO455, Now is the time to sound deaden and insulate if you are going to...I used 3" house insulation between my side panels and the sound deadener...

Rodger that on the sound deadening. Forum member Beach-Burban is sending me a sample of some he used in his Burban. Hopefully it will be just what I'm looking for. When I first removed the side panels on mine I found the PO had filled the voids with pink fiberglass insulation. The bottoms of the void spaces were covered in the fiberglass dust, in some places it was 1/4" deep. Uggg what a mess it was. The whole cab ended up dusted in fiberglass by the time I had removed it all.

Whatever product I use needs to stay intact and not absorb moisture. Originally I was thinking of using some carpet insulation but the product Beach-Burban used has piqued my interest.

[HO455]

I did some water testing and figured out which tube is which. See photo.