Boxerworks.com

84 R100S

So if I ride my bike and park it for a day there is no oil on the shop floor. But if it sits for a few days, some collects in two spots, an inch or two in front of the center stand. I'm pretty sure the leaks are from the push rod tube seals. It's not enough of a problem to make me want to re-seal the top end, as the bike runs very well. Are there any tricks to improve the sealing of these seals without a top end removal?

Tricks? Not really, on your bike.
Firstly tho, wash the area thoroughly and then ride, and look for the first signs of oil.
It could be push rod tube seal, or cylinder base? or sump?

I found a leak there on mine by washing the area well and, when dry, dusting it well with baby powder. After riding it, there was a track to where the oil was coming from. In my case it was both pushrod seals on the left side. I waited for winter and changed all 4 seals.

Several thoughts....

• If you use synthetic oils, then don't ! Not only are there very wide differences between brands and what actually constitutes a "synthetic oil", but these oils typically migrate to places where mineral oil can't get... like past perfectly good oil seals.

• I'm with Dougie... wash it first. The push rod tube seals do get hard with age and start to leak, but they also get too much bad press, and therefore undue attention. Other known culprits are the oil pressure switch and the plate covering the oil pump behind the clutch.

• At 35+ years old, you have to expect age hardening of ALL the neoprene oil seals, o-rings, and gaskets. When doing any repair task, you also have to ask yourself "what other sealing points are exposed while I have the XYZ apart ?" E.g. a clutch job is an excellent time to replace several oil seals and the oil pump o-ring. Therefore, ending leaks is a slow, progressive effort, not a focused task.

I think the Mobil 1 15w50 is a superior product. I also ran it for 7 years in my R60/2 without a problem. I'm just wondering if there is a way to externally manipulate the push rod seals to improve their sealing. Bike is running too good to disturb the top end. I haven't had to adjust tappets in the last 4 inspections. I don't want to mess with a good thing.

on the /6's the ring on the push rod tube is movable, I have a tool to tighten it against the seal, some times it will stop the leak until you get time to change the seal. If the rubber is rock hard you gonna have to change the seal.

richard t wrote: ↑Wed Sep 20, 2017 9:41 pm on the /6's the ring on the push rod tube is movable, I have a tool to tighten it against the seal, some times it will stop the leak until you get time to change the seal. If the rubber is rock hard you gonna have to change the seal.

Can you tell me anything about this tool? Is it a BMW OEM tool?

It looks something like this, I believe ...



... but this one will only work on a virtual BMW. It's a 3D model.