Where does preload oil go?

I filled my rear shock preload with oil last year (it was low), but there were no signs of leaking at the preload, the banjo or anywhere I could see. I did not take apart the shock because there was no need to get in there, and that part of the bike is hidden. While other people have discussed refilling their preload, I've not seen anyone say their banjo bolt was leaking, or the hose had a pinhole, etc. Dave D (I PM'ed him about this) is also stumped.

So, where does this oil go? Mineral oil/hydraulic jack oil is not volatile - it is not evaporating.

I just refilled and bled mine last week. Got almost an 1/8 inch more preload. What I noticed on mine was that the threads on the handle shaft were covered in oil, so I suspect it is leaking past the seal inside the adjuster barrel. If anyone has experience taking the adjuster apart and if they had any success repairing it would be great if they could chime in.

Thanks Geoff.

What you saw was likely the area where it escapes for all of us. Since I put in about half the volume of the adjuster, I expected to see oil streaks covered with dust. And if it leaks slowly out along the threads, I might not have seen it when I took my pla off.

SMSW said:

And if it leaks slowly out along the threads, I might not have seen it when I took my pla off.

Click to expand...

Bingo - I think the leak is so slow that the telltale gets washed off before it can build up. I don't think there is a whole lot of fluid in there to start with... I 've only had to do mine about every 2 years so no big deal to me.