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The ABS is trying to kill me now!

marshalguidry

New member
Riding the '02 1150RT at 45 mph on the service road about to enter the interstate and my ABS locks up completely :jawdrop. From 45 to 0 in a very short distance and luckily I'm able to pull over right before the entrance ramp but I have to shut the engine off to get them to release. I try moving up a few feet and put on the brakes and it locks up again. To give you a brief overview of what led up to this...my ABS lights started flashing two weeks ago. I checked the pads and backs were paper thin. I went ahead and changed the front and back pads. The ABS lights went off and it worked fine for a day then the ABS lights start flashing and this time I have a teaspoon or two of brake fluid on the ground under the bike. It looks like it came out of a drain line??? I thought maybe I overfilled the system ( I only added fluid to the master cylinder on the handlebar - didn't touch the main servo unit). I pulled the plastics on but didn't see any leaks. I started it the next day and the ABS wasn't flashing and seemed to work right so that's when I took it out and had this incident happen. I live 2.5 hrs from the nearest dealership. I've read the horror stories about the replacement cost of these servo units. Does this sound like the unit is going out or just a minor issue with it?
 
Your brakes locked not the ABS unit.
Your wheel circuit reservoir may be too full after installing new pads.
 
If it is that serious of a safety hazard (it sounds like it is), and you've tried unsuccessfully to fix it, I think you need to go to the dealer and find out what is wrong.

I fix just about everything myself, but sometimes you have to go to a pro.

If you continue to fiddle with it, a GS911 might help discover the problem. (edit: maybe not, I'm not familiar with the GS911 on the older 1150.)
 
There is a compensating port in the master cylinder that allows the pressure in the line to be released once you release the brake lever. If it is blocked or if the free play at the lever is adjusted incorrectly, it can result in the symptoms you are experiencing. As mentioned in previous posts, it's not worth playing with. I would recommend seeking some professional assistance with it.
 
A buddy of mine at work had an older RT like yours, and his brakes locked up, but the problem was that the brake hose on the front needed replacing. There was no leak, but it was "ballooning" and somehow caused his front brake to lock up.
 
As the pads wear, the effective level of fluid in the system decreases, as less space is taken up by pad material, and must be replaced with fluid. New pads means that you now need less fluid than before. Depending upon when you added the additional fluid (before or after pad change) would give a definitive answer as to how the problem came about. But most likely it was due to excess brake fluid.
 
Thanks guys...I'll try lowering the fluid a bit and take it around the block. The level is pretty high right now. I contacted the dealership in Houston and will try to get it in there soon.
 
If you have rubber brake lines DON'T RIDE IT.
There is a very good possibility that your brake lines are deteriorating and the debris inside is blocking the fluid return from the calipers.
This can cause brake lockup and caliper dragging or the line will balloon upon a hard brake application and the lever will go to the bar!
The rubber bits will also damage your ABS unit.
All Beemers of this vintage are doing it - don't ignore this warning.
I have fixed many BMW's of this vintage (pre '03 before factory ss teflon lines) by replacing ALL the rubber lines with Teflon braided SS lines from Spiegler.
The new lines are essentially good for the rest of the life of the bike.
The brake fluid must be flushed thru as well, to de-contaminate the ABS unit.It may need reseting as well.
The picture below shows what I am speaking of.


Note the port is entirely blocked on this fitting (cut off right behind the metal crimp)
 
As was stated here already, get rid of the stock original brake lines. The rubber may look fine, but the inner hose breaks down and collapses causing wheel lockup. It isn't a bad job changing to the stainless steel lines and bleeding the system. I did my 04 RT in three and a half hours.
 
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