ESA II leak

Can anyone confirm that there are two places that the oil could leak from in a front ESA II shock on a K1300GT ?

A) Oil from the ESA II adjustment system;
B) Oil in the actual shock absorber.

I assume the two oils are not from the same source/reservoir and that an ESA II control system leak would not be a leak from the actual shock absorber.

I believe there is only a damping adjustment on the K1300 ESA front shock. ESA can only adjust preload on the rear shock. So, if you see oil, its from the shock itself.

Now, I've been known to be wrong, so I'm sure someone will correct me if that is the case.

In general, any shock might have preload and/or compression or rebound adjustment.
Preload is usually accomplished by external spring adjustment or air pressure within the shock itself.
Damping is usually accomplished via internal valving, which may be separately adjustable for both compression and rebound.

My GS esa shock uses a motor to adjust preload, but many other bikes are manually adjustable.
My GS esa shock uses a motorized 3 position valve to adjust damping, but many other bikes are manually adjustable in finer increments.

If your shock is leaking oil, a seal has failed.

My GS esa front shock started leaking at 16,000 miles, and the only option offered by BMW was a new assembly for $2,300 for the part alone. I removed the shock and sent it to a specialty shop to have it rebuilt for $300.

Good luck with the repair. I hope it goes easy for you.

My Gs esa front shock has a large plastic box near where a preload collar would be on a normal shock. I’ve never had the box apart but Ted Porter’s video calls it a preload motor. (?)

Here’s what it looks like:



Never worked on a K1300 so don’t know if the front shock has any preload adjustment.

No problem, BC1100s. Leaking esa shocks on a BMW can be an expensive and depressing issue, especially on older bikes out of warranty. I just hope the information provided might be of some help to the OP and possibly others facing this repair.

Don’t know what year the OP K13GT is
But my 09 13GT has no esa adjustment on the front shock
Only on the rear

Thanks

Thanks to all that replied.