I couldn't even get the LocTite type correct back then, Robin. I used 242.

The whole episode can be found here:
https://www.ford-trucks.com/forums/6...ml#post4657975

Pop

 

Just discovered this terrific thread. My plug started leaking in late spring, I can see the o-ring has been partially forced out from behind the non-serviceable plug. I have the parts from Clay and have spoken to Bob about how to do this right (he recommended at least 72 hours cure time for the loctite).

I just haven't been able to devote time to remove/repair/reinstall, my back, wrist and knees are so bad. I'll probably try in the Spring. Everyone's info was very welcome and has motivated me to try to fix this.

 

That's 24 hours.

 

I posted this link above:
http://tds.loctite.com/tds5/docs/680-EN.pdf

It gives the % strength vs cure time vs temp graphs. I think the takeaways are as follows:

- on aluminum, 680 will cure slower than on steel
- on aluminum, 680 will reach only 75% of the strength of a steel seal no matter what
- on aluminum, 680 cured for 24 hours reaches roughly 73% the strength of a steel seal ( so 2% off its full strength )
- with a 0.05mm gap, cure essentially reaches 100% at 24 hours
- at elevated cure temps, 100% is reached after 1 hour.

So combine these - with a 0.05mm gap on aluminum at elevated temperatures, 24 hours should get you maximum performance out of the 680.

Cliffs notes: What bob said.

 

Over 5 years and the 242 is still holding up.

 

I think the huge variable with regard to the Loctite cure is going to be the gap. If you have only 0.05mm I think you'd be lucky. I'll bet in a typical pump with worn threads it is 3-5 times that.

Some enterprising individual could improve our plight by coming up with yet another new plug that had both the longer threads and slightly-oversized threads.

 

I think that's a pretty accurate evaluation. The gaps are certainly larger than .05mm. Here's to hoping the elevated temp cure helps mitigate the gap impact on cure time.

There's a ton of meat on this part of the pump. The real cure is to probably have a machine shop cut larger threads for the next size straight tube fitting thread profile + o-ring land with the correct surface finish for proper o-ring performance and seal it up once and right. Guess that'd probably involve gutting the pump though. There's always JBweld.

 

Any worthwhile machine shop could fabricate a complete new plug out of stainless steel bar stock, and it wouldn't take long at all. There are different classes of thread fit, class 3 being the tightest. You can get adjustable dies in order to create these different thread classes. You could probably even open the die up beyond what is normal for a class 3 fit, if you needed to compensate for worn or loose threads.

Of course, it would also probably be easy to further damage the threads by going too far, one would have to exercise caution. Just sayin', it's possible to create a part to accommodate worn threads.

LOL on the JB Weld, it certainly has crossed my mind...

 

If it ain't broke.........

Maybe someday, if the entire pump is off the truck or sumptin'..........

Pop

 

If I don't have to I will not mess with anything that has an o-ring and isn't leaking. If it's not leaking leave it alone.

The only thing on my fuel bowl that I have fixed is the leaking drain valve and the FPR rebuild because the poopet valve seal was shot and I was installing Guzzle's billet FPR housing at the time.