dual tank fuel problem

[93bulldog]

was running out of fuel on front tank, back tank worked fine. today front tank was working fine until I arrived home to find diesel all over the side of my truck and covering the undercarriage. Opened fuel cap and diesel poured out of fill. Tank showing over full but should be low after running apprx. 100 mi. on it today. Checked the back tank and it's showing M/T, (was 3/4 full).
Looks as if rear tank pumped into front tank overfilling it until diesel came out of fill cap and vent hose I found on top of front tank. now front tank acting up again. any help greatly appreciated.

[DustDevil]

Wow I've never actually heard of that happening before, bizarre. Only thing I can think of is maybe the switch is not fully changing over from one tank to the other. Anyone else got any ideas?

[phantom_smack]

They used to have a recall for inline check valves to prevent fuel from being pumped from one tank to the other.I cant for the life of me remember the recall number though.

[93bulldog]

Thanks, Looks like the control switch is bad. changing it out today. The inline check valve recall only applied to the gas engine models with fuel pumps in each tank. I appreciate the replies

[dtek]

similar problem once floats were stuck an truck would run but not well being flooded out fuel wass not comoing out cap but the fuel over flow was pusing fuel back to tank problem came when tanks were changed out an return lines were tto wrong tanks thus overflow fuel was being pumped from front to rear tank i no thius is not a deisl mine i mean but you overflow line could be on wrong an you pump could be faulty an not shutting off when it gets up to pressure thus forcing fuel to be pumped back to tank unsure off how your truuck is set up if front is primary an rear is a reserve then it just may be the return line only runs to the front tank an a stuck on pump is a possibly scenerio let me know how it goes

[shynetyme]

i have a almost the same problem with the rear tank overflowing into the front take, a mechanic told me to check the filter in the switching unit underneath. Anyone ever heard of that?