Contaminated fork oil.

Joined
Jan 24, 2014
Messages
2
Location
Folkestone
Bike
Honda ST1100
Hi all,
I stripped and rebuilt the forks on my 1995 ST last winter, fitted new bushes and seals and new Castrol fork oil (mixed 5W and 10W 50/50 to get 7.5W). I picked up a burr from a stone during a trip to Germany and ended up with a leak so when I got back I stripped the fork down. When I poured the oil out, it had only done 1600 miles, it looked like silver paint.
Is this normal after new bushes or have I got a serious problem?
I'm going to have to change both tubes, so new seals and probably new bushes too.
Any advice is appreciated.
 
Joined
Feb 17, 2007
Messages
3,105
Location
Millgrove, ON, Canada
Bike
2016 Versys 1000
STOC #
6627
What happens is you get a little aluminum, a little teflon in the oil from normal use..... don't sweat it at 1600 miles. It will be just fine until your next change interval. You shouldn't need new bushings yet, unless you feel you got significant grit past those seals and into the forks.... but if you're replacing tubes, just inspect the bushings for wear (should still have all the teflon), and providing you didn't damage them (the teflon) upon removal, re-use them.
 

Byron

Moderator
Joined
Mar 3, 2006
Messages
2,311
Location
KY
STOC #
6091
If the bushings were replaced you'll also pick up some moly is my guess as well. It's the gray coating that was on the bushings. Nothing to worry about.
 
Joined
May 30, 2013
Messages
46
Location
NW Wi
Bike
Tiger 800
Seems like every fork I've opened up had nasty looking oil regardless of themileage.
 
Joined
Mar 13, 2012
Messages
5,045
Location
soCal
Bike
'97 ST1100
STOC #
687
Hmmm, interesting. When my ST1100 was new I always noticed how gnarly the fork oil looked after 10k miles, much dirtier than other bikes I've owned, and it had that odd grayish tone to it IIRC. As the bike has aged, it seems like the oil stays cleaner between changes, and I know I'm overdue for bushings. I'm going to do them next time, so TIA for the heads up.
 

Byron

Moderator
Joined
Mar 3, 2006
Messages
2,311
Location
KY
STOC #
6091
Something to remember when looking at the bushing in the forks, my ST1300 service manual states to replace them "if there is excessive scoring or scratching, or if the teflon is worn so that the copper surface appears on more than 3/4 of the entire surface." But, you have to be looking at the correct surface.

DSC02620.jpg

In the above photo the tube bushing on the bottom of the leg looks fine. Now if you think the slider bushing on the right is bad you would be wrong.

DSC02622.jpg

With the slider bushing removed you can see the teflon coating is fine. What I'm trying to point out is you need to be sure you are looking at the sliding surface, which for the tube bushing is the outside and the slider bushing is the inside.
 
OP
OP
Joined
Jan 24, 2014
Messages
2
Location
Folkestone
Bike
Honda ST1100
Thanks for your replies, that's put my mind at rest. I'll get a move on now and get her rebuilt while there's still some summer left.
 
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