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Discussion Starter · #1 ·
Hello everybody,

Considering the many threads about the Integral brake system of the K1200 LT, and not wanting to be caught off my guard by a failure, I would be interessed to understand how it works.
Question has anyone a diagram or a technical description explaining the principles of this system and the fonctions of the different components.

Thank you

Bruno
 

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Bonjuor

Here is BMW's explanation of the system. The most important thing you can do is follow the brake fluid flush requirements. Annual on the wheel circuits and every two years on the control circuits. I have disassembled failed units and know pretty much what is going on inside.


These photos should give you an idea why the flush is so important.
 

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Discussion Starter · #3 ·
Thank you Jzeiler

The attached document seems very interesting.
I am trying to get the figures to be able to understand.

Maybe you have them...;)

Thanks again

Bruno
 

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+1 on Thanks for the article - I hadn't seen that before.

In the article it said: "You will find the figures mentioned in this article in the German issue of ATZ 3/01 beginning on page 200."
 

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I guess it has been a while since I have read that. Never did find the figures, maybe one of our German friends can help.
 

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I too was wanting to see the full details a while back. I went to the "ATZ Worldwide" website, you need to pay to get the full article. As an aside, I have the factory test documentation for the pre-delivery braking system checks on my '05 (all in German). I might ask someone at my workplace to translate it. Plenty of people have asked why BMW have elected to use such an intricate iABS system, but when the tech article is digested you can see they have attempted to control the wheels to that critical point between locking and not being locked, unlike car ABS systems which actually lock and release the wheels, hence the complexity of the control system (and the braking modulator).
 

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Discussion Starter · #7 ·
I have the factory test documentation for the pre-delivery braking system checks on my '05 (all in German).

K100 DENIS,

Could you please copy this documentation.
Even in german, it could help to understand how it works.

Thank you

Bruno
 

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Please see attached pdf of the FTE Integral Brake System test and bleed procedure prior to delivery of the bike.
 

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. I have disassembled failed units and know pretty much what is going on inside.
So,
If a failed unit is removed and repaired (or replaced)
Is it possible for a mear mortal to bleed the entire system and get the brake system working properly?
or is a visit to the dealer necessary?

I thought one of the important things was to NEVER get air in the unit... or a special tool/procedure etc. would be necessary... :confused:

ps
thanks for the reply on my other post/thread.
 

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Very interesting read. I am even more impressed with its capabilities. It is a shame they system could not be maintained without all those expensive flushes for us non mechanics. I guess our safety is worth it ?????
 

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So,
If a failed unit is removed and repaired (or replaced)
Is it possible for a mear mortal to bleed the entire system and get the brake system working properly?
or is a visit to the dealer necessary?

I thought one of the important things was to NEVER get air in the unit... or a special tool/procedure etc. would be necessary... :confused:

ps
thanks for the reply on my other post/thread.
Yes it is not rocket science to bleed the system, a flush is much easier and that is when you don't want to allow air in. Any time a component is replaced, caliper, hose, etc. you must perform a bleed of that circuit. The only thing you cannot do that the dealer can is run the bleed test with the computer. But now you can do that with the GS-911 units.
 

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. But now you can do that with the GS-911 units.
OK, Gotcha..

I'm going to remove the unit this weekend and take it apart to see if I can find anything obvious.... honestly, I think it's probably gunked up from going 80K miles without a control flush. :rolleyes: (let this be a lesson boys and girls)

But anyway, If it still don't work I'm gonna yank the entire thing... and run traditional lines from master cyl. to calipers

I will unbolt the electrical box/plug and retain it... like you mentioned in a few other threads...

I'm sure you see me sniffin around... :histerica
 

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John,

Just pull the output ports where the outgoing lines were. They have a long fine filter on them and that will give you an idea of the internal condition.
 

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Found a burned section in the circuit board...
any idea if this burned section controls the servo to the front or both?

I am thinking that was the problem... the screens for the input and output looked fine.
however the brake fluid looked like a fine Colombian coffee.. :(


Anyway, I decided to remove the entire system. The brakes in the front feel great when I was done..
That is, until the right side rubber hose ruptured.. :rolleyes:
so, I will be ordering SS lines for both front and back.

They are the stock lines (2002) so It's about time to replace them anyway... actually glad it broke now and not in east bumphuck...

concerning the burned section on the board, My brake lights and speedo were working previous... so I think I will be OK plugging it back in.


burned section is top left hand corner.... click on it to enlarge pic.
 

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That would be the driver chip for the Front circuit pump. I had a board with some of those but I had sent it to a guy in Holland to fix his unit. Most likely cause was crud in the pump that stalled the motor and burned out the chip.
 

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. Most likely cause was crud in the pump that stalled the motor and burned out the chip.
Yep,

I took apart the abs/servo assist control unit.. and that side (front) was very dirty.... also the motor on that side was dead... I reckon when the pump was getting tight it took out the motor and the chip.....

the other motor spins fine with 12v

Oh well... it's all in the garbage can now... waiting for my Galfer SS lines.

thanks for the help (again)

and sorry Bruno for hijacking your thread.... ;)
 

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Yep,

I took apart the abs/servo assist control unit.. and that side (front) was very dirty.... also the motor on that side was dead... I reckon when the pump was getting tight it took out the motor and the chip.....

the other motor spins fine with 12v

Oh well... it's all in the garbage can now... waiting for my Galfer SS lines.

thanks for the help (again)

and sorry Bruno for hijacking your thread.... ;)
Sounds like it could be a source of spares for John Z...
 

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