Brake Problem 1150GSA

[johnyboy]

Not sure if this condition has been covered before, but here we go.
sequence of events...
1.servo whine came on, and stayed on for 20 minutes.
2.red triangle comes on and stays on, flashing ABS.
3.transmission seems knotchy when braking.
4.servo stops working, but brakes seem sharp and firm at lever.
5.brakes start to fade
6.servo whine stops
7.warning lights still flashing and triangle continuous
8.brake lever coming nearly back to bars, but she dont want to stop.

where do i start looking?????? any advice, greatly accepted

 

[Voyager]

where do i start looking??????

I'd start with the Oilhead Section



Bob.

 

[johnyboy]

I'd start with the Oilhead Section



Bob.

sorted cheers.should have put my glasses on...

 

[Hubs]

All very familiar, after two years of messing around with batteries and different stop lights and brake fluid changes, I threw away the servo ( not far, it's very heavy).

No warning lights, start up problems or anything anymore, just a brake system that works like I expect it to.. cost was one new hose and a few hours.

No ABS admittedly, but didn't have it on previous 15 bikes either! (except for a K1200S with servo brakes which, guess what, failed...)

Mine was a 2002.

YMMV

 

[johnyboy]

All very familiar, after two years of messing around with batteries and different stop lights and brake fluid changes, I threw away the servo ( not far, it's very heavy).

No warning lights, start up problems or anything anymore, just a brake system that works like I expect it to.. cost was one new hose and a few hours.

No ABS admittedly, but didn't have it on previous 15 bikes either! (except for a K1200S with servo brakes which, guess what, failed...)

Mine was a 2002.

YMMV

If you get rid of the abs, does the servo become redundant?

 

[Fanum]

Sounds like a switch has got stuck on.......check both microswitches to make sure they operate properly.

I don't know what the result of a server being kept on for that long would be, but piston seals blowing under pressure or possibly brake fluid boiling if one set of calipers are kept applied (which could explain the lever to the bars and knotchiness maybe? )

I'd start by checking operation of both microswitches (they are quite distinct when you operate).......I had one seize ON with mud clogged up on the foot switch once and it caused similar problems until I cleared it.

 

[Hubs]

If you get rid of the abs, does the servo become redundant?

I think that is right - the servo is there to make the ABS work, I believe, so no ABS, no need for servo. The master cylinders, callipers and hoses are all retained in the un servo'd setup, and are the same parts as are used in the non servo version of the bike.

The relay on the back brake was running permanently for some time on mine - only realised how noisy it had all been once I'd got rid of it all.

For me, removing the servo transformed the braking system from constantly unreliable, noisy and pretty poor ( except on the odd occasion it all worked) into a great set of brakes, although without ABS. And at 10 years old, probably the best way forward ( again, in my circumstances).

 

[johnyboy]

I think that is right - the servo is there to make the ABS work, I believe, so no ABS, no need for servo. The master cylinders, callipers and hoses are all retained in the un servo'd setup, and are the same parts as are used in the non servo version of the bike.

The relay on the back brake was running permanently for some time on mine - only realised how noisy it had all been once I'd got rid of it all.

For me, removing the servo transformed the braking system from constantly unreliable, noisy and pretty poor ( except on the odd occasion it all worked) into a great set of brakes, although without ABS. And at 10 years old, probably the best way forward ( again, in my circumstances).

cheers for the replies. i will have a look at the switches, then if no better, sounds like the most practicle solution is to remove the servo system

 

[Fanum]

The rear one tens to be the culprit......the mechanism can easily be gummed up with road crap and stuff.

The rod that connects the cyclinder with the pedal in particular gets mucky, and can lead to the brake not turning off after being applied.

There's a threaded adjuster on it......try cleaning all around that and make sure the microswitch turns on AND OFF when the pedal is used......it's only a tiny adjustment needed, and i seem to remember having to tweak mine up a little so it didn't activate the servo on every bump at some point