Fuel tank valve o-rings

[Arborigine]

85 F-250, 6.9. My fuel switchover valve shows signs of seepage so i want to replace the o-rings.
My Ford dealer said i have to buy the plastic hoses to get the o-rings, no kit available. Not gonna happen. I think I need 12 rings, plus more on top of the tanks.
I have a kit selection of Buna-N o-rings, but not sure thats a good idea with the ethanol added to diesel around here.
Got a source, dimensions, or a part number?
Thanks

 

[Arborigine]

BTT, no one has ever replaced these o-rings? I guess i will have to do it the hard way.

 

[Truck#3]

They put ethonal in diesel?

 

[GreenDiesel]

If you know the size of the o-rings you need(use some calipers), you can order them in viton from McMaster Carr

your rubber ones will prob be fine too, as long as your not running high bio concentration, i would think

 

[Arborigine]

Its California, they put something in to "oxygenate" it. Had a class action suit with a payout for a new pump 15 years ago.
I figured if someone had the size i could just order new rings and not be down for a day. I guess not. They aren't sucking air, but seep enough for dust to collect on the valve.

 

[RLDSL]

Go to the *Help* section of any parts store, and they sell those viton orings and caps, Harbor Freight sells a nice assortment of small Viton orings that has those sizes too, but be forewarned, if you try to change those little buggers, you are going to need a couple of small pick tools, some oring lube, lots of light, one of those magnifier glasses thingys comes in handy and a great deal of creative language with an emphisis on things best not mentioned in front of small children
After fighting one of the blamed things, you may get a real strong urge to rig a chunk of rubber hose and clamps on the things and be done with them, or just get the repair kits ( also available in the help section but a lot more expensive where it has the cap the the orings already in it with a length of that hard plastic hose and a metal splice barb)

 

[snicklas]

If I remember correctly from a previous thread..... the industry size ID for the Return O-Rings is

111 (one-one-one)

Hope this helps...

 

[franklin2]

If I remember correctly from a previous thread..... the industry size ID for the Return O-Rings is

111 (one-one-one)

Hope this helps...

He is not replacing those. He is trying to replace the ones on the fuel lines at the switching valve. I believe they are the same fittings they use on the fuel injected cars and trucks. Those clipped quick-disconnect things.

 

[Arborigine]

Update, the fuel o-ring size is 5/16 and they are the brown rings. I must be spoiled by spending my life working on euro cars, it looks like Larry the Cable Guy decided where to put the valve. Looks like I'm going to have to drop the front tank to change the o-rings. Putting it 6 inches further forward would have prevented that.

 

[Arborigine]

More update. I dropped the front tank at work today and discovered that the return lines are 5/16 and the supply lines are 3/8 inch. I get to do it again! To do the whole system 10 of each size are required.