Diesel Bombers - Fuel Filter/Separator Drain Valve Repair

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Fuel Filter/Separator Drain Valve Repair

Thanks To: sabre2th - https://www.dieselbombers.com/members/sabre2th.html

If you're smelling fuel, seeing fuel drip from the back or from the separator drain tube on the passenger side of your Powerstroke, or have a puddle growing in the valley on top, there's a good chance that this is the problem. Seems that the newly mandated ULSD (ultra-low-sulpher-diesel) likes to shrink these o rings...
Well, here's how I did it. Took about 25 minutes and only one beer. My rig is a 99.5 F250, so if yours is a 7.3 PSD with 4 screws on the valve, these pics will apply.. I'm told that the procedure for the older models is similar. Click on the pics for a larger view. If anyone has info to add, let me know.

Fig.1
Get yourself some good #202 O-rings (1/4" I.D.- 1/8" cross-section), preferably Viton as it holds up to diesel and temp changes very well. The ones pictured here are brown colored, but they can be black- same material. I ended up buying a lot of extras just to get a good price.

http://home.centurytel.net/sabre/fig1.JPG

Fig.2
Begin by removing the plastic cover over the filter/separator (13mm socket). This would also probably be a good time to remove your battery cables to keep your friends from nicknaming you "Sparky" or "Torch". There are some hot solenoid connections close to where you will be wrenching.

http://home.centurytel.net/sabre/fig2.JPG

Fig.3
Place a suitable container under the passenger side of your engine below the drain tube to catch fuel. (Note: this pan was not pushed back far enough, had a pretty good mess to clean up...a short hose attached to the end of the drain tube will help.)

http://home.centurytel.net/sabre/fig3.JPG

Fig.4
Rotate the drain valve clockwise to drain your filter/separator. Be sure to check the position of your drain pan at this time... (This would also be a good time to disconnect any electrical plugs that may be in the way.)

http://home.centurytel.net/sabre/fig4.JPG

Fig.5
Push the rubber connector to the drain tube off of the lower part of the drain valve. A big fat screwdriver worked good for me.
http://home.centurytel.net/sabre/fig5.JPG

Fig.6
Remove the 4 T20 (Torx) screws with a small T20 socket and ratchet. You might want to place a towel or such below the valve so you don't have to fish a screw out of the valley like I did..

http://home.centurytel.net/sabre/fig6.JPG

Fig.7
Note that the valve assembly is in 2 parts. It's real easy to drop the lever part into the valley. (Don't ask)
http://home.centurytel.net/sabre/fig7.JPG

Fig.8
Carefully pop the old o rings out of the valve body, taking care not scratch up the o ring seat or valve.

http://home.centurytel.net/sabre/fig8.JPG

Fig.9
Wipe any existing crud from valve pockets and push in the new o rings. On some models, there is a third o-ring on the top of the stem (pull the stem out from the top to replace), these ARE included in my kits just in case. Wipe any crud off the o ring surfaces on the filter/separator and reverse procedure to re-install.
http://home.centurytel.net/sabre/fig9.JPG
You're done! Kick back and admire your work, no more liquid gold leaking out onto the ground...

Thanks, DieselMinded for posting this for me. Hope it proves useful!
Tom

Very cool and useful for those with this problem! Good writeup and pics!

where did ya get them O rings?

Your post was terrific. No problems for me though I spent a little over an hour. Took the o-rings (pure diesel power) to O'Reilley's and found two more in a $7.95 assortment. They were designed for fuel lines so now I have a couple of spares. Thanks
cowbum

Nice write up. The only thing you need to watch with the assortments at the parts stores is the quality. You really want to use the Nitrile o-rings. I think I got a pack of 25 for $5 from McMaster Carr. The regular o-rings will work, but won't last as long with the diesel fuel.

I had to have that done to my 1999 7.3 PSD, so I bought the valve body for $44 then I went over to my friends house{he's a aircraft tech & ground equipment tech} Had it done in no time, If i were to do it, it would have taken me all day, And I would have busted a knuckle ???

Quote:

Originally Posted by DieselHardware (Post 281078)

Buna-N (Nitrile) will work fine as that is what comes in the factory valve but if you want some that will be the last ones you have to install with the new ULSD, use Viton. Independent studies have shown that Viton holds up against ULSD and BioDiesel better than any of the more common elasotmers available.

Ford sells a kit for like $17 that includes just the O-rings. OR you could pay $44 like^. I believe there are also a couple O-rings around the valve itself that sometimes leak as well.

Quote:

Originally Posted by kazairl (Post 281524)

Ford sells a kit for like $17 that includes just the O-rings. OR you could pay $44 like^. I believe there are also a couple O-rings around the valve itself that sometimes leak as well.

But the Ford kits are Buna-N. For less than what Ford wants for the o-rings, you can get a complete kit of every o-ring found on the fuel bowl plus the Parker fuel line sleeves, all made of Viton.

^true. When My buddies 99 did this I bought some Vitons from McMaster-Carr and had then next dayed for cheaper than what Ford wanted for them.

Thanks for the post, very helpful. Nice to know just what I'm doing BEFORE I get started.
I went ahead and replaced the whole thing, didn't want to find out later that the plastic was cracked.

I also replaced the fuel filter while I was in there, since the fuel was getting drained and making a mess anyway.

Mine started leaking last year when it got cold.... i bought the oring kit from Smallparts.com....then the leak quit and I never installed them....now it's cold again and a hint of a leak again... can't find the orings....

But...thanks to your post and in depth instructions i feel confident to tackle this finally!

Viton is what I meant.....:argh:

Quote:

Originally Posted by DieselHardware (Post 298345)

Viton is what I meant.....:argh:

We knew that :ok1:

BTW, you do know that there are 3 o-rings in the drain valve, right?

Quote:

Originally Posted by guzzle (Post 298382)

BTW, you do know that there are 3 o-rings in the drain valve, right?

where doe's the 3rd one go? I haven't had to do mine yet, but I thought there was only the 2 on the side

There is one at the top of the valve stem that keeps all the grit and grime away from the internal movement of the drain valve. Without cleaning the stem and changing the top o-ring when the fuel seal o-rings are changed, the grit that has made it's way into the valve will quickly wear on the new sealing o-rings and prematurely cause them to leak. This is true for all Ford 7.3s from 94 to 2003.

Ever wonder why some say that they just changed their o-rings and in a few of months it is leaking again?

Here is my writeup on the drain valve that replaces all 3 o-rings in the drain valve.