fuel leak at rear tank - Diesel Forum

duneburner · 08-14-2007, 12:03 AM

a little history first....both my tanks had the original fuel strainer/pick up in the tank. they both finally deteriorated and started sucking air before the tank was empty. i fixed that problem but i think i created another one. after replacing the strainer i now have a fuel leak at the rear tank. it only leaks when it is sitting in the sun and the tank becomes pressurized. when i remove the cap and release the pressure the leak eventually stops. I'm thinking that the leak is coming from either the return line connection or the suction side connection. when i had the tanks out and disconnected the fuel lines maybe i boogered up one of the o-rings in the quick connect fittings. can i replace just the o-rings. if so, where can i get them. are they a dealer only or will my local parts store have them?

does this make sense?

cdnsarguy · 08-14-2007, 08:35 AM

Replacement fuel line parts are at most AP stores....... the large sender seal is a good bet also.... was there a rollover valve on your tank too.... Remember topping off the tank is NOT recommended by ford.

duneburner · 08-15-2007, 01:49 AM

i took off the roll over valve when i harpooned the tank fill pipes and made an external vent hose. if it was the rollover valve or sender seal i dont think it would still leak when the tank wasnt completely full. [img]/ubbthreads/images/graemlins/shrug.gif[/img]

duneburner · 08-15-2007, 01:56 AM

i havnt had a chance to drop the tank yet but im thinking it will be obvious where the leak is when i do

duneburner · 08-26-2007, 06:02 PM

looks like i fixed the problem... i replaced the o rings in both the fuel supply and return lines at the tank. what a pain it was trying to find parts for the fuel sender/strainer for this truck. i finally just got an o-ring assortment and did the best i could. the leak may have actually been at the seal for the sender(witch i couldnt find either). i used some silicone with the old seal and no leaks yet.

**awardmont** · 07-02-2011, 03:12 PM

Hello
I was wondering if you had any pictures of what the tank inner parts look like. I have a 1994 f 350 IDI , I need to drop my tanks and clean or replace them, front tank makes motor run rough except at freeway speeds, i have 285,000 miles about 30,000 gallons between the 2 tanks. do you replace internal parts in tank when replacing or cleaning?
Thanks Mike