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Discussion Starter #1
Ok, so I've gotten my hands on a 05 R1200GS from a friend who didn't ride anymore, and it had some ABS problems. Now, I'm just as dumb as the next idiot, so of course I refused to take it to the dealer and figured I could fix it in the spring/summer and now fall. And now I'm here, so any help would be awesome.

Issues listed from the dealer were a bad ABS module- as far as I know, classic 1200GS problem. I managed to get a used module from AUS for far far less than they wanted new. ABS warning light on, seemed to be the issue. I got a GS911,and confirmed this was the issue (can't remember the fault codes). So I swapped the modules, no problem, followed the long bleeding process. I even bought the JVB service video. Front brakes work great- with the battery on, servo pump comes right on and locks the wheel.

However, the REAR brake does not work, and the ABS light still is on (although, that may be because the serial numbers of the module are different). Bleeding doesn't seem to work- with a full res and all the lines connected, no matter how much I pump no fluid moves through and the brakes don't close. I thought this was 1) bad caliper, bought and replaced, no change. 2) Bad master cylinder, bought and replaced, no change. Of course, I also used new brake fluid of the correct kind. I also noticed that when the rear master cylinder is hooked up, and battery is on- the servo pump does NOT come on. As far as I can tell, I am getting no fluid signal from the master cylinder to the ABS module. I even un connected the ABS module from the master cylinder and no fluid moves through it when pumping. Did I get 2 bad cylinders? Is my brake line bad?

I really, really, really don't want to give into the dealer...help! if this isn't the right thread, point me in the right direction, please!
 

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Sounds like the rear servo pump is not working. Sometime a whack with a hammer will dislodge a stuck brush on the servo motor. If this is the case its a temporary fix and the brushes need replaced. Or most likely the servo unit is dead and you have several choices

1. Source yet another new Servo/ABS pump and hope it is operational
2. Spend $3,000 + on a new unit and have the dealer install it so you have a 2 year warranty
3. Sell the bike chea becaeu th ebrakes are failed
4. Spend about $10 and ditch the Servo/ABS set up and go with traditional non-ABS brakes.

5 weeks a go I bought an 05 R1200GS knowing there was potential for the ABS to be shot. As it turns out front work fine rear was dead. Next day I removed the Servo/ABS unit made 2 brake line jumpers and blocked the dash lights.

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Here's what the lack of maintenance looks like.

Here's a link I used for most of the servo-ectomy but made hard brake line jumpers instead of contorting the stock brake lines/fittings:


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What area of the world are you from. If you local I can help you out if you want the servo-ectomy done and also maintnenace items like pulling the swingarm to inspect, clean, service and/or replace the pivot bearings and also checking, inspecting and lubing the drive line splines in their entirety

Or if your not interested in modding the bike and want to sell it to get out from under it I might be interested.
 

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Discussion Starter #5
Thanks for the links. Servo failure aside, shouldn't the rear master cylinder pump fluid from the reservoir even if it isn't attached? Nothing pumps out of it.

I'm in western MA
 

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Yes it should but it could also be the bleed nipple or caliper could be plugged with dirt/corrosion not allowing fluid to pass.


With the key on and the rear brake pedal pressed do you hear the servo pump running?


If the pump is not running no mater how well the master cylinder works you'll only have residual braking. When you actuate the brake pedal the brake fluid is pushed from MC towards the servo pump where the pressure is boosted via the pump. Then from the servo unit the booted pressure is directed towards caliper. If the pump is not operational the MC by itself is not big enough to move all the brake fluid in the system that is why braking is reduced.
 

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Discussion Starter #7
Yes it should but if the pump is not running no mater how well the master cylinder works you'll only have residual braking. When you actuate the brake pedal the brake fluid is pushed from MC towards the servo pump where the pressure is boosted via the pump. Then from the servo unit the booted pressure is directed towards caliper. If the pump is not operational the MC by itself is not big enough to move all the brake fluid in the system that is why braking is reduced.

With the key on and the rear brake pedal pressed do you hear the servo pump running?

With the key on and rear brake pressed, the servo pump doesn't run- there's no distinct "whine" like there is with the front. When the pedal is pushed, no fluid and no pressure comes out, so nothing is going to the pump as far as I can tell.
 

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Discussion Starter #8
Yes it should but it could also be the bleed nipple or caliper could be plugged with dirt/corrosion not allowing fluid to pass.
I thought that too, reason for the new rear caliper assembly, but it didn't help. To get even simpler/stupid, even with the just the MC, reservoir, and line that goes to servo (not the one that goes to the caliper itself), when I pump no fluid goes out the line.
 

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2 thoughts;

Contact Module Masters for rebuild service
Option #4 from list would that allow front ABS while rear would be non ABS
 

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Discussion Starter #11
2 thoughts;

Contact Module Masters for rebuild service
Option #4 from list would that allow front ABS while rear would be non ABS

Yeah, I talked to module masters a few months ago, at the time it was a 6 month wait and $750.

I was also told by them: "you can swap the control modules safely and the bike will recognize your old vin in the module. You can get the module re-coded, but that really depends on dealer willingness."

So that's an option too if I feel extra stupid.
 

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Module Master always comes up as the saving grace in these situations and all I can say is call them again and verify that they can rebuild BMW iABSiii in its entirety if needed. Yes they do woks on many different ABS pumps with great success but the BMW iABSii is a very different animal. They can install new brushes in the pump motors IF that is the problem you okay but if the servos are bad (this is more often than not the case) you are SOL and back to making one of the 4 decisions listed above.
 

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Discussion Starter #13
UPDATE:

I actually got the who fuckin shebang to work! I frankenstien'd the piss outta it- removed the original control until from the module- 4 five lobe security torx, 4 connectors on the board, did the same thing with the new/used unit on the bike, put everything back on, and it worked like a charm. Who knows how long it will last, but it works now. I still have a flashing brake failure light, which i think is only because the wheels haven't moved and a low battery, but the brakes work and the GS911 reports no faults.

Thanks everyone for the help.
 

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UPDATE:

I actually got the who fuckin shebang to work! I frankenstien'd the piss outta it- removed the original control until from the module- 4 five lobe security torx, 4 connectors on the board, did the same thing with the new/used unit on the bike, put everything back on, and it worked like a charm. Who knows how long it will last, but it works now. I still have a flashing brake failure light, which i think is only because the wheels haven't moved and a low battery, but the brakes work and the GS911 reports no faults.

Thanks everyone for the help.
Hi , got 2006 r1200gs . Think same issues break fail on dash . Breaking lag . Taken to bike garage today plugged in no faults found . Advised take bmw .
before I do this . Checked to read your issues sound same . How’s your running now ? Thanks Wes
 

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Discussion Starter #15
Hi , got 2006 r1200gs . Think same issues break fail on dash . Breaking lag . Taken to bike garage today plugged in no faults found . Advised take bmw .
before I do this . Checked to read your issues sound same . How’s your running now ? Thanks Wes
When i checked with the GS911, I had rear brake issues on my original module- low rear pressure failure. With the new module I bought, I had a non matching serial number. I'd say take to bmw, pay the $100 to figure out exactly what is wrong. Could also be electrical switches or needs to be bled.

All of the errors went away once I had the frankenstien module in and got the tank/wheels moving. Taken for a ride around the yard before my plates came in, everything seemed to work.
 

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There really is not Frankenstein'ing anything! You either replace the unit or bypass it and cover up the warning/hazard lights if you do not what them to be seen. The OEM system either works or I doesn't.
 
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