Funny thing ..... the front brake (single disc Brembo) began acting strange 20k miles after it was rebuilt, along with master cylinder. Keep in mind, the GS doesn't have a bunch of brake, since the rear is a drum/shoe affair that has never had much stopping power.
I was riding a couple of days ago, and noticed that the front brake took an excessive amount of pressure to get any stopping power at all, to the point where it wasn't safe.
I brought the bike home, not knowing exactly where to start ..... I was thinking 'brake bleed.' But before I started on that, I pulled the caliper and popped the brake pads of 20,000 miles and noticed something I'd never noticed before.
- the brake pads are square
- the edges of the pads 'hang out' over the edge of the brake rotor
- this caused the pads to have a curved 'unworn' portion across their tops.and the worn part with at least a 1/16" more wear.
It almost liked like the brake rotor was too small in diameter for the pads.
Anyway, I had a spare pair of EBC FA18 from a hundred years ago that were the correct p/n for the bike. So I installed them, and the front brake's power was instantly restored. The FA 18s were identical to the pads I removed.
But why would a brake pad be manufactured that didn't make total contact with the rotor?
Any of you Beemer owners ever noticed this?