USD forks stanchions threaded into the lower legs, sealing.

Riejufixing · World Chat Champion Joined: 24 Jun 2018 Karma :

The Rieju RS3 125cc fork stanchions are threaded into alloy legs (see: https://www.bikechatforums.com/viewtopic.php?t=324969 ).

The threads need to be sealed I assume, to stop fork oil from passing the threads.

If that's true, what to seal them with? Ordinary thread seal e.g. Loctite 565? PTFE tape? Something else?

almostthere · Traffic Copper Joined: 28 Oct 2013 Karma :

wut?
____________________
Beer, It's the reason I get up every afternoon
www.mfairco.uk

Riejufixing · World Chat Champion Joined: 24 Jun 2018 Karma :

It's OK, it seems I'm doing something that is rarely done. Looking at the picture, number 15 screws into number 14. Number 15 itself is full of oil, and the threads on the number 14 end of number 15 (I have now skilfully edited the picture) need to be sealed, else oil will creep through between the screwed-in number 15 and the number 14, which is undesirable.

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

Again, the answer will probably be, "look at the old one, what did they do there?".

Check for an o-ring or fibre washer in the bottom of the end casting that's not shown on the parts diagram. Have a close look at the thread. Might it be a taper?

In any case, I can't think of any way in which it would be wrong to use PTFE tape on those threads.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

Ste · Not Work Safe Joined: 01 Sep 2002 Karma :

Riejufixing · World Chat Champion Joined: 24 Jun 2018 Karma :

Riejufixing · World Chat Champion Joined: 24 Jun 2018 Karma :

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

I would clean it up with brake cleaner and assemble using loctite 243.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

Riejufixing · World Chat Champion Joined: 24 Jun 2018 Karma :

No sealant seems to be in use. There was a light-alloy component pushed into the bottom of the fork stanchion (easy sliding fit) holding two "O" rings sealing to the insides of the stanchion. This component also held another O ring sealing to the machined flat inner bottom face of the lower leg.

See "Removing stanchions from USD fork alloy lower legs." write-up:

https://www.bikechatforums.com/viewtopic.php?t=325193

The pictures attached showthe component with O rings, and the stanchion threads filled with corrosion from the inside of the lower leg from when it was withdrawn.