: 1150RT ABS Modulator


Steve1150RT
Apr 16th, 2011, 3:46 am
I have a 2003 1150RT. A few weeks ago the brake failure warning light started flashing (4Hz) and warning light stays on solid. Shortly after that, when applying the front brake it intermittantly looses power - when braking hard the brake seems to 'jerk' from full to residual power. The back brake seems fine. I took it to my local bmw dealer who announced the ABS modulator had failed, repair cost 1700. After some research online it seems not to be an uncommon problem with this model and there are some horror stories of the brakes locking up completely and throwing riders off their bikes.

I am horrified that a manufacturer such as BMW can have such a serious fault with a model and not do a recall, am I right in thinking this?

I bought the bike a year ago from that dealer and they have given me 2 choices: they will repair the bike at cost price (1400) or I can sell it back to them for 2400. I bought it from them for 5500 !

I cannot afford the cost of this repair so I'm totally stuck, Any suggestions?

steveaikens
Apr 16th, 2011, 5:40 am
You're not stuck.

First, try resetting the ABS to clear the fault.

http://www.wikihow.com/Reset-the-ABS-on-a-BMW-R1100RT-Motorcycle

My 2000 R1100RT-P modulator crapped out on me. After several reset attempts, I simply put a piece of electrical tape over the light to keep it from being a bother when I rode it and went on about my business.

Keep in mind that the ABS isn't required to enjoy the bike safely. The only difference is now you don't have "anti-lock" brakes, just the same brakes we've been using on motorcycle since we first moved to disk brakes on bikes. Don't let anyone BS you about that and for sure, don't give that bike back to the dealer for that kind of loss.

ABS is a nice feature for some, but it's an added feature. FYI, GS models have a switch to turn ABS off. Think about that when you think about whether it's safe to ride without ABS.

No problem that you can't overcome.

dadicool59
Apr 16th, 2011, 5:40 am
I have a 2003 1150RT. A few weeks ago the brake failure warning light started flashing (4Hz) and warning light stays on solid. Shortly after that, when applying the front brake it intermittantly looses power - when braking hard the brake seems to 'jerk' from full to residual power. The back brake seems fine. I took it to my local bmw dealer who announced the ABS modulator had failed, repair cost 1700. After some research online it seems not to be an uncommon problem with this model and there are some horror stories of the brakes locking up completely and throwing riders off their bikes.

I am horrified that a manufacturer such as BMW can have such a serious fault with a model and not do a recall, am I right in thinking this?

I bought the bike a year ago from that dealer and they have given me 2 choices: they will repair the bike at cost price (1400) or I can sell it back to them for 2400. I bought it from them for 5500 !

I cannot afford the cost of this repair so I'm totally stuck, Any suggestions?
Im not familiar with the 03 RT but my first thought was if there was a non ABS model, can you have it refitted to bypass the ABS module.
As hard as it might be, finding the money for the repair is really your best option as Im sure you dont want to rip up 3000.

japachap
Apr 16th, 2011, 1:47 pm
Before panicking- try the reset,; try a full brake fluid renewal; check the abs sensors are at the specified distances from the ABS sensor discs (I broke one once and Ive also seen bent ABS senor discs send faults to the ABS system); check your brake light switches arent sticking on during statup...
Just done the fluid renewal on my 03 RT (possibly the first time in 4 years, if not from new!) and it strikes me that the fluid level setting in the ABS reservoir is not an exact science (hence thr overflow catch tank on the US models).
Theres plenty that may be causing your problem... before you shell out on an I-ABS module...

Steve1150RT
Apr 18th, 2011, 1:47 pm
Thanks for all the advise. I'll check all those things. Motorworks have an 'abs removal kit' which can turn these bikes into non-iABS bikes, basically removing the abs modulator and re-directing the brake pipes so it turns into a standard hydrolic brake system. Apparently the abs modulator also controls the servo-assisted part of the braking system as well as the ABS, and its the servo part that is broken on my bike, but I''ve been told that standard brakes work fine on them. I've found a garage that will also do this job for around 200, they say that riders report the brakes work perfectly well with this system.

Has anyone else had this done to their bikes?

beech
Apr 18th, 2011, 5:45 pm
I have heard of someone taking the servo pump out of the bike and working on it by reversing the polarity of the power quickly, breaking it free. Generally your problem stems from not changing the fluid often enough and the failure you describe is a common complaint in bikes of your vintage. I have a friend who has done the black tape modification and rides with no worries. I like the method of re routing the plumbing and eliminating the unit if you can not replace it. Black tape will also be needed or remove the bulbs even better. Sorry for your problems but a solution will be found that will let you keep riding. Possibly even a used ABS unit. On the GS bikes BMW even sells the correct tubes and hoses to take the bike back to non ABS. A search of the on line parts fiche sites will show this. I agree that this is a pain. But as mentioned carefully look at all the things that can give a system fault as mentioned in one of the posts above. Fluid level in the abs unit itself can do this. As I understand it, your bike is a servo assist type? If so there are 4 circuits not 2 in the brake system. The servo system 2 each and the wheel system 2 each. Many people don't realize this and just try to bleed the system as an old fashioned brake system. Not so simple. I don't remember when the servo bikes started so I may have included confusing information.
In short, I like your idea of the kit if no straight forward fix is available and you can not go for a new pump.
Parts diagrams: http://www.maxbmwmotorcycles.com/fiche/fiche.aspx

Steve1150RT
Apr 22nd, 2011, 2:11 am
I've got the bike booked into garage week after next, they are going to check all the items you recommend and if still cant get going then will get the kit from motorworks and remove the abs. As you mention, this bike is servo-assisted so the 'power brakes' function will also be removed, but I've had plenty of reports that the brakes work perfectly well, there is less to maintain thus less to go wrong, easier to service, and even been told it does not affect resale value very much because savvy purchasers know of this problem and they are reassured that it cannot happen on this bike. How much of this is true remains to be seen but I have no plans to sell it in the near future anyway (although I do sometimes look at the 'k' series and imagne!)