Gas pours out unused right tank 81 K30

[farmall]

I have been using my left/drivers side tank since I bought this rig a few years ago because when I switched the tank selector switch the gauge did not change.

Recently I have noticed that if I let the truck idle or after a drive or even first thing in the morning there will be up to a quart of gas that comes out the right/pass fuel fill opening/cap.

This 81 K3500 has a 454 with a two line fuel pump with no return line and no sign of a hard return line on the frame rail.

A real head scratcher.

My NAPA is having a friends and family sale next week so I am thinking of getting a new switch and selector valve.

I also have an 87 parts truck with dual tanks but I have not been under either truck with fuel selector on the brain to see if they are the same.

I found this thread to be of great help.
http://67-72chevytrucks.com/vboard/s...d.php?t=567277

I do not know if my selector valve has return ports or if they are capped or open and I cant think of why my right/pass side tank would be filling up.

I would like to get this fixed and don't mind buying the new parts but if my new valve has return ports do I just cap them?

Ideas?

My build thread.http://67-72chevytrucks.com/vboard/s...d.php?t=643974

[464elky]

I would think you definitely need a new selector valve. It sounds like it is transferring/leaking fuel over to the right tank some how. Capping off the returns is no problem if the valve has them.

[Gmc.guy]

If I remember right I think the selector defaults to the right tank every time the ignition is off, then to left once on again. And if it fails it will go back to the right too. Maybe it dumps a little every time to the right It has been awhile since I've messed with one