R1100RT ABS--At wits end

[Freightdawg]

Please don't shoot me if I should have posted this under "other bikes."

Here's the down and dirty. I purchased a 1998 R1100RT about 2 months ago. Shortly after I got it, I started having problems with the ABS. About every third start, the ABS lights would stay on after moving (can't remember if they were flashing together or alternating), but would go out after turning the ignition off then restarting the bike.

A couple of weeks after getting the bike I brought it into the local stealer for the 48K inspection and asked them to look at it. When I picked it up, lights did not go out, even after turning the ignition off and restarting. Was reassured by all-knowing mechanic that they would extinguish after I drove 14 feet. They never did go out. Brought the bike back in and was assured it was a poor battery. Unlikely, I thought, since the previous owner had replaced it earlier this year. But I told the mech to put a new one in so we could test his theory. A couple of HOURS later, he tells me it's not the battery but the ABS unit itself. $2K for a new one. That would boost the cost of the bike by nearly 40%. I said the brakes work fine, put my battery back in and give me my bike.

Fast forward to last week. I purchased a used unit off of eBay. Less than $400. When I pulled the battery, fluid was low in 4 of 6 cells. I thought that was supposed to be topped off at the 48K inspection. Doubt it would have burned off that much water in less than two months if it had been serviced properly. Topped the fluid, put it on a charger, and found out it wasn't holding a charge. Maybe it IS the battery. So, purchase brand new, sealed battery, lots of go-go juice. Same problem.

Fast forward to today. Finally get around to pulling ABS unit. Old one out, new one in, bleed brakes, and things seem to have improved. Before, the two ABS lights would flash together regardless of whether I'd just started or was well down the road. If I press the ABS switch, the top ABS light would extinguish and the bottom one would remain on steady. After some time (4.5 minutes according to the books) both would start flashing in unison again. After putting in the new unit, I got alternating lights again. I got excited. I brought the bike back into the driveway and did the ABS reset (see wikihow.com). Now I'm back to where I was with both ABS lights blinking together.

Dad is thinking maybe an ABS sensor problem. I can't find anything on how to check where that problem might be. Any suggestions? Do I just need to take it back to a dealer? Is there a trustworthy mechanic in the Louisville area without going to the Louisville BMW dealer? Anyone have any luck with the service department at the BMW dealer in Indy?

Maybe I should just cover the lights with black electrical tape.

Open to any and all suggestions. Thanks.

JR

[Arbee]

There is only one remedy for ABS...

Remove it completely and throw it over a cliff,

brake hose replacement costs to make it non ABS are $268

Dealing with ABS problems, you are dealing with your own life
these things decide when & where they are going to operate
irrespective of the riders wishes at the time, faulty ABS can
decide not to operate at all, intermittently...

lets hope it not when you need it most

You can remove the ABS relay to remove flashing lights and place it in the spare relay socket.

[philbytx]

FYI - BMW ABS is extremely sensitive to low voltage.

ADVRider has a good ABS FAQ/FIX section but I can't get the link (I'm at work!). Another thing to do is to make an ABS fault light, there are posts out there giving the Radio Shack parts for it. One thing is to check the gap on the wheel sensors. If you have access to a DMM, you can check battery voltage and also resistance figures. The DMM and fault light should locate the issue quite quickly.

Here's some links to basic guides to ABSII and some cures.

http://www.largiader.com/abs/abs2.html
http://www.ibmwr.org/r-tech/oilheads/AB ... ndex.shtml

ABSII is unlinked and kind of brain dead to work on compared with the iABS and EVO systems of the later bikes.

Good luck !

[roadglide]

Did you try to measure and shim the sensors at the abs rings on the disk .

[omg1010]

In most cases it is just a weak battery. I'd suggest you drive a bit (maybe 10-20 kms) with the flashing lights. Stop, turn of and restart. If the flashing lights go out now when you start riding you can be sure it is the battery. Or put the battery on a charger overnight and see if the problem still exists. If no, change the battery, if yes, see your dealer.

If the problem continues you dealer would be the best address to go to and they will check the fault-memory and can say where the problem is. Removing the ABS and throwing it over a cliff is bullsh... An ABS is a very usefull gadget and should be compulsory on every motorbike.

Kind regards
Oliver

[roadglide]

On my last ABS R 1100 the ABS unit went south to replace the unit 2K for a bike that was worth 2K to 3K dose not make sense. So it was not worth it, even for a used abs unit.So I pulled the ABS bulbs and relay you know what the bike stopped fine but no ABS that's all. As long as the braking system is sealed and good meat on the pad the bike will stop fine just wont have abs pulsation I rode the bike for a season and sold it. I just bought another one a 96 and had to replace the rear disk and ABS ring. Measure the run out with a dial indicator re shim and she works fine. The R1100 is one of the best Bike I have owned with or with out ABS

[tas]

i know that this is an old post and the problem is probably resolved by now, but the tale that you relay is exactly like mine.

it turned out, in my case, to be a weak battery.

i spent many pounds at my local bmw garage having the abs checked yet they failed to spot a dry cell in the battery.

bottom line. i fitted a maintenance free battery that works like a dream, even powers my heated clothing and i now travel an extra 30 miles to another bmw garage.

my new battery is from these guys.
http://www.bannerbatteries.com/banner/home/index_en.php