1150GS rear brake lets go....

[BikeLugger]

My bike has always done this and I'm not sure if it should. Hopefully you fine people will be able to help. It's an '02 1150GS with Servo + ABS brakes.

When I come to a stop and hold the bike on the rear brake only I have noticed the pitch of the servo whine drop, just before the rear brake lets go and I roll back a couple of inches. The bike then comes to a stop with a low servo grunt followed by silence (well as close as can be achieved with an oil head.)

This happens when I'm facing up an incline, I haven't ever noticed it pointing down an incline. (I haven't tried either)

The rear brake will pull the bike up ok on its own although it is no where near as sharp as the front. It feels like it needs quite a bit of pressure applied to slow it down in a hurry. I have managed to activate the rear ABS at slow speeds on a brick paved area.

All fluid levels are fine, warning lights go out as they should.

Is my servo dying?

Matt.

 

[GSmonkey]

My servoed '04 12GS used to do this from new.

Oh - and welcome to the site

 

[rudiemoto]

hi matt
when did

1 changed the brake fluid....in both servo and master
2 checked the level
3 brake pressure check
4 checked rear brake pistons
5 checked rear brake piston seals
6 checked brake pad thickness
7 had a bike tech thats bmw or bike trained to check all above

ring me on 07903090254
i will give you a hand for all above
and welcome to the madhouse

 

[Bryn]

I was under the impression that the servo on the back brake 'pulsed' so if the back brake held on only the servo would come on and off as needed to keep the pressure up...

The front on the other hand whines away continually

 

[roddy]

when using the rear brake only at a stand still the servo will cut out once up to pressure but you should still have brake pressure,
the front brake will run the servo constantly when it's used.

not much use but maybe helpful to know

 

[ahutcheon]

My '03 1150GS servo/ABS has done what's described for as long as I can remember, whether facing uphill or down. I doubt the movement is as much as a few inches, not enough to have to change footing but enough to know that the brake "relaxed" for an instant. If it's a sign of impending failure, it's been impending for almost 7 years now.

 

[BikeLugger]

Good news, thanks guys.

I'm quite happy to see it's another case of 'they all do that sir.' It's my first BMW so I'm still learning all the quirks. I've just done a fluid service with a valve check and throttle balance.

Still to do the clutch and brake bleed, never quite trusted myself with hydraulics on anything other than my mountain bikes so I might be in touch rudimoto. I'm only in Preston so not too far away if it all goes wrong!

Oh by the way, hi! I'd been lurking for a while and forgot I hadn't said hello. Thanks for the welcome.