GS 1200 brakes – problems & possible solutions

[virco]

I have had last year, in the short time I had to ride my GS1200 until the bad weather came down, a nagging experience with the brakes.
At one fuel stop I put the gas pump nozzle in an awkward position and some fuel spilled out on the tank and under it (as I have seen some dripping down). I didn’t worry a bit about this and just wiped the tank with a bit of paper tissue in order not to stain. 5 minutes later when leaving the gas station I almost ended up in the middle of side traffic because the brakes were working much less efficient than before I pulled in for gas. Initially I thought that some gas had spilled on the front brake discs and pads and made them slippery but I checked and it wasn’t so. After that I noticed the ABS sign on board blinking. I did not pay attention to this when I first left the gas station because, as you know, the ABS light blinks for a few meters after putting the bike in motion after having the engine turned off.
To my surprise I realized that what it happened was that I had no more power assistance in the brakes: little stopping effect on normal lever pull, no “buzz” from the power brake pump when pulling the lever and no ABS. The cause of this I thought at the time to be probably an electric contact disturbed by the spilled gas. I was pretty much annoyed because such an occurrence is not unheard to happen and a serious manufacturer should foresee and protect any parts subjects to be affected by it, especially on a machine that is supposed to be as sturdy and fool-proof as the GS1200. So, a bit put off by all this I waited for the gas to evaporate and the supposedly affected contact to resume normal operation. To my even worse surprise that didn’t happen that day, nor the next one, so after another day of very slow riding and pulling very strong on the hand brake lever only to get very mediocre stopping results (as otherwise warned in the operation instructions to happen when power assistance fails) I called the dealer to set up a service appointment.
Unexpectedly, after 2 more days of keeping the bike in the garage waiting for the service appointment, when I took the bike out to leave for the dealer, brakes resumed normal operation from the moment I started the engine: the soft buzzing of the power assistance pump was there and braking was strong and efficient once again. So after riding a few miles to make sure everything was ok I called the dealer and canceled the service appointment. To this day, that amounts to cca. 200 miles after the incident, I had no more similar problems with it but a feeling of unreliability persisted.
Meanwhile I have learned that there is the option to buy the GS1200 without the ABS and I wonder if anyone here has one of these and what experience it had with it. Does the braking is still power assisted and dual linked?
I know that the ABS can be turned off even on the models that have it installed, but as I somehow lost confidence in the power assisted mechanism, not in the ABS itself, I was thinking what if I just got rid of all the electronics and gizmos (the power assistance pump, linked brakes and ABS altogether) and replace them with a more powerful pump at the lever linked directly to the front calipers (the same mechanical pump-caliper system for the back wheel) as so many other motorcycles have.
Any opinions on this? Has anyone here done such a modification, and if so with what results? Thank you.

Cheers,
Virgil

[DeFens]

Don't confuse ABS with the servo-assisted braking. They are separate features. Disabling one won't necessarily disable the other - in fact, you can disable the ABS on purpose to travel loose surfaces, etc.

Did you by any chance knock the right handguard askew when you were gassing up your bike? If you start the bike with one of the brakes actuated - even slightly - it will disable the servo-assist. I confirmed this when I had a slow tipover while riding on a dirt road. The bike itself wasn't damaged much (a couple of scratches in the handguard). However, in the tipover the guard rotated just enough to engage the end of the brake lever. When I started the bike, the ABS light blinked rapidly and the servos didn't work, just as you describe. I figured I'd really messed something up. After riding a couple of miles I saw what had happened, adjusted the handguard, and the system was fine.

I seriously doubt that the gas overfill had anything to do with your problem - I'm not even sure that there's any brake-related wiring that gas could get to in the way you describe.

[virco]

Originally Posted by DeFens

Don't confuse ABS with the servo-assisted braking. They are separate features. Disabling one won't necessarily disable the other - in fact, you can disable the ABS on purpose to travel loose surfaces, etc.
....
I seriously doubt that the gas overfill had anything to do with your problem - I'm not even sure that there's any brake-related wiring that gas could get to in the way you describe.

Thanks for the input. I certainly don't confuse ABS with servo, I just said that when the incident happened to me, none of them worked. I don't remember starting the engine with the brake lever pulled (in order to cancel servo as you say it happens) but I might have. What I am positive about is not having the brake lever accidentally knocked off. I will pay attention on this feature.
Cheers!

[malloy]

In addition to the handguard contacting the front brake lever as DeFens mentioned, sometimes the rear brake lever doesn't return fully to the closed position. There is a 10mm adjusting bolt on the lever itself that actuates the brake light and servo switch when the lever is depressed. It has a domed shaped top that sometimes allows the tang on the switch to slide off which activates the switch acting as if the brakes are on so you get the ABS fault flashing light and the brake light is always on. You can adjust the the bolt upwards. I ended up replacing the stock domed bolt with a stainless steel bolt that has a flat top. This seemed to fix it for me as the tang no longer slips off the head. Also the switch itself can be moved about a little in its mount that also helps.

Turn the ignition on but don't start the motor. Get your head down by the rear brake pedal and depress it. You should hear a faint click as the switch is opened and closed. Also the brake light should go on and off. If the brake light is continually on and you don't hear the clicking, the problem is probably with the adjustment of the switch, adjusting bolt and/or the bolt head allowing the switch tang to slip.

Good luck!

[andyclift]

It happened on mine. It started as an occasional problem which was solved by stopping and restarting the engine. It then got worse and aften a restart did not help but it worked OK the next day.

The cause was a sticky front brake switch. If the brake was held on when getting on the bike the switch was not resetting before the bike was started. The result is the bike's systems assumes the brake is being held on so it won't complete the brake test and goes into residual mode.

Mine got a lot worse on a two up holiday as I was holding the front brake on hard while my wife got on the pillion. Eventually I noticed the rear light looked rather bright reflected in a shop window. Got the switch changed the next day and no problem since.

[Pancho]

Those problems with switchs and handguards were one of the things my dealer told me before leaving with my new bike. "always pay attention on brake levers to make sure everything is ok so the ABS doesn't fail on the pre ride check".