Oil leak diagnosis challenge!

[riceburner]

So - got to work this morning to find an oily smoke coming off the rear of the catalyser box!

MONDAYS!!


I'm pretty damn sure it's coming from the rear shock absorber, evidence:

Very light oil (light coloured and thin) at the very base of the shock
Underside of swingarm show no oil APART from a small area around the shock lower mounting point (no trails from anywhere 'uphill' of that cutout.)
Similarly, top-side of swingarm shows no trails of oil from anywhere 'uphill' of the shock mount, and a small 'cloud' of oil (well - oily dirt) around the shock mount only.
The oil currently on the catalyser seems to be limited to a small amount that is obviously coming from the lower shock mounting point and nowhere else.

The shock itself seems dry - the shock body and the coil (that can be reached with the unit ON the bike - ie not much of it), seem to be dry of any oil, but it could be running down the inside/underside of the coil, or, I think the shock body has a cover over the lower part, which would hide a minor trail from view.

Bit hard to provide any further info as a) the unit is still on the bike, b) I'm at work without any tools, and c) it's raining out there.

Current plan is to tie a bit of cloth around the lower part of the shock to minimise dribble onto the catalyser and ride carefully home this afternoon, then drop the shock to confirm the leak before sourcing a replacement or a fix.

The next issue will be FINDING a replacement..... the Rockster shock (shared with the R850R Classic) is not exactly common.....

[dark_knight87]

Just a thought but also check the rear brake system in case there is a split pipe or it is weeping from the reservoir?

Regards,
Russ

[riceburner]

I did think that, and will check it again, but there was no visual sign of a leak on that side of the bike. I'd expect the master cylinder and foot lever mount to be wet if the reservoir or hose were leaking.

[riceburner]

The shock has a plastic shroud over the main chromed piston rod, so without diss-assembling the thing it's not a 100% confirmed diagnosis, but the fact that there's oil obviously weeping from that 'drain hole' on the underside of the unit makes me 99.9999% certain that the seal has gone.

So - in amongst working from home tomorrow, trying to get a webserver working, I'm going to have to track down either a replacement, or a rebuilder nearby.

(No other vehicle at the moment.... I hate being dependant on public transport )

[towerworker]

Riceburner.....I saw your post a couple days ago but this didn't hit me until just now as I was re-reading. In the summer of 2004 I was about 18 months into ownership of my '03 R. I started noticing a very slight burning toast smell each time I stopped. But could find no leak anywhere. After about 10 days of this I was visiting my daughter and as I got off the bike there was visible smoke as well as oil leaking down on the cat from the back of the transmission. It was the output shaft seal, oil was leaking down on the cat. Early on it was so slight that there was no visible evidence. That progressed quickly. Bike had 16K and I had just changed the tranny gear oil to synthetic. I guess the new synthetic seeped thru the seal. I hope you've found the problem but thought this may be worth looking closer at.

[riceburner]

Riceburner.....I saw your post a couple days ago but this didn't hit me until just now as I was re-reading. In the summer of 2004 I was about 18 months into ownership of my '03 R. I started noticing a very slight burning toast smell each time I stopped. But could find no leak anywhere. After about 10 days of this I was visiting my daughter and as I got off the bike there was visible smoke as well as oil leaking down on the cat from the back of the transmission. It was the output shaft seal, oil was leaking down on the cat. Early on it was so slight that there was no visible evidence. That progressed quickly. Bike had 16K and I had just changed the tranny gear oil to synthetic. I guess the new synthetic seeped thru the seal. I hope you've found the problem but thought this may be worth looking closer at.

It's a good thought. I'm pretty convinced that this time it's the shock - there's absolutely NO oil trail from anywhere to the shock mount point on the swingarm, and the bike is filthy enough that the oil that has collected is very blatantly the only oil there. The dirt over the outer cases holds oil quite well and will betray it's presence quite clearly. (one benefit of not cleaning the thing* )







* This is a facetious comment, obviously.

[sweatmark]

Any chance leak is from preload adjuster?
That's a "glass half-full" troubleshooting inquiry.

[riceburner]

Any chance leak is from preload adjuster?
That's a "glass half-full" troubleshooting inquiry.

I did wonder that, but i couldn't see any leaks near the joins.

[sweatmark]

Any chance leak is from preload adjuster?
That's a "glass half-full" troubleshooting inquiry.

I did wonder that, but i couldn't see any leaks near the joins.

My Ohlins rear shock leaked on Rockster 1. Leak was at transition from flex line to fitting. Result was similar to your discovery of oil/dirt in same locations.

[Tigcraft]

Im intrigued to what’s going on...

[swamper]

My new TFX shock blew out and oil all over the Cat. for two weeks and 5,000 miles. Left puddles under the bike at stops.

[riceburner]

Im intrigued to what’s going on...

Errr, the K just got a new tyre, the Rockster is sulking in the corner, and it's peeing it down.

[Tigcraft]

Im intrigued to what’s going on...

Errr, the K just got a new tyre, the Rockster is sulking in the corner, and it's peeing it down.

And I’m chilaxing with a beer!