R1100S brake trouble

[gypsytech]

I'm working on a 2001 R1100S, and the front brake is acting
strangely. The ABS warning light is out, and that's the only fault
registered on my GS911. But the lever action is unusual; the first
pull has excessive lever travel, the second less, as if the brakes
need to be "pumped up". The master cylinder does hold lever pressure,
even on the first pull, and the brake works OK at stopping the bike.
Could these 2 problems be inter-related?

[Tom Cutter]

<< I'm working on a 2001 R1100S, and the front brake is

actingstrangely. The ABS warning light is out, and that's the only
faultregistered on my GS911. But the lever action is unusual; the
firstpull has excessive lever travel, the second less, as if the
brakesneed to be "pumped up". The master cylinder does hold lever
pressure,even on the first pull, and the brake works OK at stopping the
bike.Could these 2 problems be inter-related?>>

Doesn't sound like a GS-911 or ABS Module related issue. I suspect that
the issue should be take n to a more general BMW-tech list for help,
but it sounds like there is air in the lines. You don't mention whether
your have Servo-Assisted (called "whizzy" by some) brakes. If so, pad
wear can cause a low fluid condition in the servo.

-- 
Tom Cutter
Yardley, PA 
www.RubberChickenRacingGarage.com
"If the moral codes of a society are to survive, the actions of an
adult life cannot be forgiven or excused by the difficulties of
childhood." Randy Wayne Wright, (writing as Randy Striker.)

[doherty wayne]

bleed them

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[Brendan Kelly]

Hi by any chance have you split the calipers open.

Brendan Kelly.

[Martin]

I had a similar problem on my non abs r1150rs. There should be a bleed nipple up on the brake master cylinder where the banjo connector fits ( due to the angle of the drop bars on the s and rs range it forms a high point for an air pocket ) plus there is another bleed down on the head stock ( I was not aware of this one and it was part of the problem) as well as point one BMW recommend vacuum bleeding but I found the good old method worked best. So go check you haven't missed a bleed point

Martin

[Pancerz, David W]

I'm going to echo what the previous guys have said. The moment I read
the original email I thought it was an issue with air in the brake line.
While not as bad on BMW's, you haven't chased down bleeding problems
until you've owned a Ducati! A couple of caveats from this experienced
old soul:

1. I prefer the old fashion gravity way of bleeding the brakes (and
clutch) versus all the fancy power bleeders, MityVacs, suction this and
flux capacitor that. And believe me, I've bought them all.

2. Bleed the line more than once. Even if you think you've done it
enough, once more won't hurt.

3. Lightly tap on the caliper and other areas that potentially could
trap a bubble. Start at the bottom and work up. I'll use either a
rubber mallet or a combination wrench. I did say tap "lightly" !!!

4. Finally, as Martin suggests look for those smaller bleed nipples
hidden up around the bars, reservoir, and master cylinder. The slight
tapping usually breaks those bubbles loose and they rise to these areas.

Best of luck. If it's not air in the line I owe you an adult
beverage...

David

[Tom Cutter]

<<I had a similar problem on my non abs r1150rs. There should be a
bleed nipple up on the brake master cylinder where the banjo connector
fits ( due to the angle of the drop bars on the s and rs range it forms
a high point for an air pocket ) plus there is another bleed down on
the head stock ( I was not aware of this one and it was part of the
problem) as well as point one BMW recommend vacuum bleeding but I found
the good old method worked best. So go check you haven't missed a
bleed pointMartin>>

Place the motorcycle on the SIDE stand, with the handlebar turned to
the left just enough to make the master cylinder reservoir parallel to
the ground. In that position, the relief hole in the master cylinder
will be the high point of the system. remove the cover and rubber
bellows, GENTLY tickle the brake lever to make the bubbles move up and
out the fluid in the MC.