Fuel Filter/seperator drain o-ring replacement...my first write up

[jlrsn]

Stewart,
I also learn something new every day! I have a lot of old outdated publications archived but use the Internet to keep me up to date. One quick easy to understand source for up to date compatibility of O-Ring Seals to the fluids they are exposed to is:

O-Ring Fluid Compatibility

I have other URLs that I use but they get really technical.

I used to have thousands of O-Ring Seals in stock for my aircraft as a Certificated Commercial Air Carrier and I really liked the shelf life of the Viton as I had to provide the traceability of the materials used to the FAA and the 20 year shelf life made it easy as long as I maintained the Certs provided with the O-Rings.

I don't think the O-Rings that you used are going to have a catastrophic failure but I'd keep some AS568A-202 Vitons on hand for the next time you're changing out your Fuel Filter Element. The AS568A-202 O-Rings are the same as the McMaster-Carr P/N: 9464 K118 O-Rings.

Good luck,
Jim

[klhansen]

[ QUOTE ]
[ QUOTE ]
Viton is the best choice for the Fuel Drain Valve. Good luck,


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I'm only going by the info from the web, but according to the information at the McMaster-Carr website, the PTFE O-Rings are as good, if not better, than the Viton O-Rings.

Stewart

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I think you may have trouble with PTFE o-rings. They may be more resistant to just about anything, but they're rated at Shore D:55 for hardness (approximately Shore A:100) while both Buna N and Viton are at Shore A:70-75. The "extra hard" PTFE may not physically seal as well as the softer "hard" Viton o-rings. Besides that, they're more expensive (granted not much in the big picture at $0.80 each vs $0.22 each for Viton)

I think I'd stick with Viton.

[Stewart_H]

[ QUOTE ]
I think you may have trouble with PTFE o-rings. They may be more resistant to just about anything, but they're rated at Shore D:55 for hardness (approximately Shore A:100) while both Buna N and Viton are at Shore A:70-75. The "extra hard" PTFE may not physically seal as well as the softer "hard" Viton o-rings.

[/ QUOTE ]

Considering what I spend on my vehicle mods and maintenance, $10 bucks really isn't much.

Oh well, if the PTFE O-Rings don't seal well enough because they're too hard, I'll just pick up a pack of Viton rings.

I already gave away the extra PTFE O-Rings that were in the package I got, so it won't be a big deal to me if I have to order more O-Rings. I'll just have more to give away! [img]/ubbthreads/images/graemlins/smile.gif[/img]

Stewart

[myf350]

Add one more set of o-rings to the list. Mine started yesterday. I had already bought the parts, just haven't changed them yet, now I will have to.

[batmans4x4]

thanks for the info i saved the $100.00 laber cost from the dealer.one quick tip stuff a rag under the drain valve so you don"t lose the small screws when you drop them.like i did . LOL

[maxrules]

Found my drain valve leaking yesterday. I ordered 10 Vitons from smallparts.com, only $5.60 shipped to me. My biggest concern is what this new diesel fuel is doing to the rest of the system/engine. There is absolutely no doubt in my mind this leak was caused soley by the ULSD. With all the sue happy people in this world, I'm suprised the EPA isn't paying for all these repairs yet. A lawyer should jump all over this. I might slip in a puddle of leaked diesel and spill hot McDonald's coffee on myself.

[olddieseldude]

Has anyone put a part number or size to the (3rd) o-ring that fits around the drain valve stem? It's much smaller in cross section and larger in ID than the other two o-rings being discussed in this thread.

Also I temperarily patched my leak this past weekend (I didn't have the real o-rings yet) but on the subject of tools to use, I found that my 1/4" thumb ratchet worked very well with a torx bit to get the screws in and out. I did have to break them loose with a regular 1/4" ratchet but the thumb ratchet removed them and replaced them quickly.

I also found removing the drain tube hose from the valve (without breaking the drain valve) to be the toughest part of the job.

Also, it was a good time to tighten my turbo tube hose clamps. All but one needed tightening.

[olddieseldude]

I found it, #013 - .426 ID x 0.070 Thk.

Correct me if I'm wrong though. After thinking about it a little it would seem to me that that o-ring sees no fuel until the drain valve is opened, is that true?

[klhansen]

[ QUOTE ]
I found it, #013 - .426 ID x 0.070 Thk.

Correct me if I'm wrong though. After thinking about it a little it would seem to me that that o-ring sees no fuel until the drain valve is opened, is that true?

[/ QUOTE ]

I measured that o-ring and came up with the same size.

You are right, the stem o-ring doesn't see any pressure. Not sure why it's even there. The two -202's will fix up the valve.

[Wheel67]

Thanks for torque spec, Jim. That's around 2 ft/lbs so I think I'm good.
Airline Pilot, Huh? I flew Tomcats in the Navy.

[jlrsn]

I put in the Torque Specs as members requested it but facing reality 25" lbs is basically snug. I have the calibrated Torque Screwdrivers that cover 25" lbs but it is almost impossible to get the tool into the area to torque the screws without major disassembly.

That Tomcat was one really impressive flying machine! I initially flew round engines (R2000, R2800) in the propeller days but retired flying a G4 Internationally.

[kcastle]

Add another truck to the list of o-ring replacements. On the bright side, I found a minor coolant leak around my thermostat housing.

[444-4D]

You can add me to the list too.

[mushing_madness]

After 3 tanks of ULSD - add me to the list. Changed them out 2 days ago!

MM

[Raymondb]

I knew it was coming and thought I had the proper o-rings on hand.

Ended up ordering from McMaster's web-site.

Dang things won't be here 'til Tuesday.

prt