K1100RS Rear Master Cylinder

[MCrenshaw]

Headed out on the '94 K1100RS to run some errands the other day and didn't get to the end of the drive before I realized the rear brake didn't brake.  Pedal would go all the way down but no friction at all.  What seemed odd was there was no leaking brake fluid to be seen.  Brake hoses look good.  Master cylinder had clean fluid.

Suggestions on how to trouble shoot?  Bike has ABS, and I did a full ABS bleed and refill last Fall so it hasn't been six months yet.  Obviously there is air in the system and I'm wondering if this could be master cylinder related.

[johnny]

greetings mcrenshaw...

every now and then i can feel my pedal going down a little further than it should for that amount of pressure...

if i keep on riding eventually it will go down all the way with no pressure...

each time this has happened the pads were good the master had fluid and there were no leaks...

what i did was bleed the brakes... abs 1st caliper 2nd... and that fixt it each time it has happened... on two rs eleven hundert motobricks with stainless lines...

the most infamous time was at the top of ca190... on a fieldmeet no doubt... 24 miles of nertly downhill switchbacks ponderosa to springville... pedal had been soft for a few hours... so there was enough notice... gottsa 11mm boxer in my bung for this very reason...




j o