wierd fuel problem

[gudsgf]

hey guys, just bought me a 77 k10 and i have this wierd problem. its my first 4x4 and first truck with dual tanks. theres a bunch of hoses disconnected at this cyndrical thing under the bed. the fuel is pulling from the left tank. but as its running it fills up the right side tank and leaks out the filler neck tube. throwing my gas away, and then i run out of gas because it never pulls fuel out of the right side tank. i have know clue where to start with this. any help would be greatly apreciated thanks.sorry for the rant.

[ray_mcavoy]

Hi gudsgf,

Sounds like the return lines are crossed on the tank selector valve (that cylindrical thing). Or the valve has an internal leak allowing fuel to flow into the wrong line(s).

There should be a total of 6 lines connected to the selector valve. Three larger 3/8" feed lines and three smaller 1/4" return lines.

Of the 3 return lines, one leads back from the fuel pump and the other 2 go to the tanks (one line to each tank). It sounds like the two return lines leading from the selector valve to the tanks are crossed up, returning fuel back into the wrong tank.

Edit: I just noticed you said there were some lines disconnected from the selector valve. That sounds like someone bypassed it so it's only running off the left tank now. And in the process, they probably hooked the return line back from the fuel pump into the right side tank instead of the left. Find the 1/4" return line going into the left tank and hook that one into the 1/4" return line coming back from the fuel pump.

[gudsgf]

i apreciate the timely response wasnt sure if i was clear enough. what you said makes sense ill try it out in the morning and report back again thanks for the help.