View Full Version : rear tank over flowing????

04-07-2009, 12:54 AM
walking out to my truck(90 f-250 5.0L) after l got off work l saw a new gas stain on the road and the mud under my rear fuel door was wet so l took off the cap and gas came pouring out.

l syfened out a bunch into my jerry can and left for home, after scratching my head for a bit.

when l got home l opened the door again and it blead off vapour.

l was running on my front tank and what l am thinking is insted of the gas returing to the front tank it is getting pumped into the rear????

has anyone ever heared of this? or have a fuel system diagram?

dirka dave
04-07-2009, 02:21 AM
Sounds like a one way check valve is stuck open.

FU Toolbag
04-07-2009, 06:24 AM
I'ld say that your tank selector isn't switching the return line.

04-07-2009, 08:59 AM
try running on yur rear and see if it still overflows

04-07-2009, 09:32 AM
will let you know how it works out

04-07-2009, 09:41 AM
check the vent maybe there was a pressure build up . was it sitting in the sun?

04-07-2009, 11:49 AM
not realy l filled it up befor work at around 1:00pm and saw it over flowing at 11:00pm.

just got back from driving around on the rear tank and it sure as hell is over flowing again.bat1bat1

l am about ready to throw a match at it.

also have another drivability isue that l am trying to work out. unrelated. ball joints or wheel bearings or somthing.

04-08-2009, 12:02 AM
ok l am beginning to think that the evap system isn't working causing a preassure build up and the only vent would be through the filler cap.

because l after l shut the truck off and syphoned about 30L out of the tank. l came back a few houres later and opened the cap again and sure enough there was a hissing comming from it.

04-08-2009, 10:22 PM
could be the breather clogged up?

or is that too simple

hows the front bumper?

04-09-2009, 07:22 AM
had a same problem with a customers truck last month
it was the switching vavle filling the rear tank
put a new valve in and it was problem solved

dirka dave
04-09-2009, 09:24 AM
Have a look down the filler pipe with a match...

04-09-2009, 08:24 PM
been working all through the day the past few so l havent had a chance to cheeck it out. hope to have it figgured out this weekend.

front bumper is pulled away from the fraim alittle where l put the strap though 2 weeks ago. any one know where there is a tree l can use to push it back in with?

04-10-2009, 09:40 PM
well drove around all day today on the front tank with no problems and havent ran out of gas yet so l am guessing that the return lines are in proper working order and just the rear tank isn't venting.