[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

ABS Failure


I had an 1150 RT with the same system you have on your RS.  It didn't give
me any trouble, but then again, I didn't hit a driveshaft. 

The first thing I'd try is completely draining and re-bleeding the whole
system just to eliminate the possibility that air is in the servo side of
the system.  Read up on this before you try it.  It's tricky.  You may want
a qualified dealer to do it who has the BMW computer equipment.  

The brakes were the worst thing about this beautiful bike they weren't
really bad, but neither were they exactly rider friendly.  When the engine
was on, the brakes were too sensitive making it a real challenge to make
smooth stops.  When the engine was off, like pushing it around the garage,
it was very hard to get any braking power.  If I were spending the kind of
money you're considering to fix them, I'd definitely look into either
upgrading to a newer ABS Servo system or simply putting a good non-ABS
system together for the bike.  

The fact that your bike was in an accident will affect the resale price
anyway. I don't think you'll be out much money in the long run to change the

The later hex-head system is less touchy and has more non-servo power when
the engine is off.   

There are list members who've dumped their ABS simply because they didn't
like the pregnant pause that happens when you hit a bump with the brakes on.
Perhaps one of them can give you guidance.  

The newer '07 bikes have an even better and simpler system.   It might be
good to check the parts books with a creative dealer and see what
alternatives you have.  If I were spending 4 digits on a repair, I'd like to
get an improvement, but perhaps you can get the job done cheaper by just
bypassing the ABS and servo systems altogether.     


Date: Thu, 21 Aug 2008 06:37:26 +0000
From: paul kalichman <pkalichman@xxxxxxxxxxx>
Subject: Integral ABS module failure


I have been lurking on the list for the last 2 years since I picked up an 02
R1150RS.  Not much to say or add
all that time so I just keep quiet. I really enjoy the bike, and I find it
really refreshing after 23 years of riding an
R80RT.  That being said, I have some drama to share, and a query to ask at

This June I had a little encounter with a object lying in the middle of a 4
lane divided highway I happened to be riding.
In spite of my 30 years riding experience, (and the fact that I know better)
still managed to fixate on the object,
and consequently ran right over it, at perhaps 120KPH!  The impact was quite
severe, as the object in question was
the driveshaft that connects the two rear axles of a dump truck. Rather
and heavy. Amazingly the bike went right over
it, but it did result in an exciting tank slapper. I managed to keep the
upright and aimed her over to the shoulder.
Once I was able to pry my fingers off the grips and dismount the bike, I
noticed the side stand had grown longer as
it couldn't be fully extended.  With difficulty, I hauled her up on the
stand, which had also grown longer.
Slowly I regained my senses and it dawned on me that the stands were not
longer, but the bike was in fact
lower as I now had two flat tires.  Indeed, running over a driveshaft at
highway speeds will result in badly bent rims,
flat tires, and at least one bent brake rotor and damaged caliper.
Fortunately this was all covered by my insurance,
to the tune of $5700 Canadian dollars.

Now three weeks later I am in Montana heading to Glacier National park after
the MOA rally. I attempt to slow down
for a RH turn at an intersection, nothing happens!  No brakes!  I squeeze
harder. Next thing I know, and I am doing a
stoppie and the rear wheel is off the ground. I see the warning lamp on, and
the ABS flashing at 4 hertz.
(At least one brake circuit in residual braking function mode)  I quickly
deduce this isn't looking too good.
Not one to let a minor inconvenience like intermittent malfunctioning brakes
to end a good trip, I continue
for a few more days, until I have to head home.  During the 2000 mile trip
home to Toronto, I note the following
symptoms. Sometimes I have only residual braking in the rear, but power to
front. Other times only
residual braking in the front, but power to the rear. Other times no power
either front or rear.
Last but not least, but most of the time, full power to both, but warning
light on and ABS lamp flashing.
In all cases the failure only happens when I use the brakes, never at start
up. (and never consistently)
Eventually I do take the bike over to my local BMW dealer. Fault codes
a faulty iABS modulator.
Repair estimate from BMW Canada, $500 labour and $3600 for the modulator!
(that's not a typo)
Needless to say, with a little googleling one soon finds the same part is
approximately $2000
in the US. Now I am quite sure BMW Canada has a very good reason for
$1500 more than their
counterparts in the US.  Perhaps the Canadian version comes with a life time
warranty? Maybe its
gold plated?  (I am positive if customer service ever returns the three
I made last week, I will
find out!)

But until then I have been thinking of plan B.

Plan B: I order the modulator from the US and install it myself.
(I like plan B because I am one of those cheap BMW self maintainers)

So the question I have been unable to resolve even after searching and
every iABS related
thread on the planet.

Is the ABS modulator a plug and play unit right out of the box? (of course
after filling and bleeding!)
The current part number 34517685790, is listed for the RS, GS and R models.
Is there some
special set up or adjustment that only a BMW dealer can perform with their
diagnostic computer?

I suspect the unit is in fact plug and play, and the computer is used only
test and record
results. But I have no way to verify this, and I do not want to order a part
install!  Does anyone on this list know the answer?

Hope I haven't bored everyone with my long drivel.

regards, paul


End of oilheads-digest V4 #201

E-mail message checked by Spyware Doctor (
Database version: 5.10520e