[Cefoul]

Great, I got it all. Now I have to try to fix mine.
I collected 5 ABS 3 units.- 3 from BMW 1150 and 2 from k1200 LT, I'm not going to run out of parts

Hi Chris,

You can use a lot of the internal parts between the various models except for these 3 things which are specifics to each model (K1200LT, K1200RS/GT, R1150RT ....):

1/ The electronic board is specific to the model

2/ The pressure relief valve is colour coded. Even on the same model, the front and the rear units are sometimes different. I have seen blue, yellow, white, green colour dot on the top of the black cap.
These valves are used to stabilize the pressure created by the pilot when the brake lever is pulled.

3/ The integral piston located in the first section of the unit. It depends if it is an Integral ABS or a Semi-Integral ABS.

As long as you can order the correct seals (FPM) and replace all of them, and the capability to check the 4 internal pressure sensors (GS911 can do it), you might be able to rebuild a working unit.
These pressure sensors and the DC motors are the most problematic parts.
Some components on the main board can die, due to a problem with one or the 2 DC motors but it is more or less an easy fix.

Good luck,

 

[ChrisFrench]

Thanks for the great advice, it's a job for this winter.
As I said, in the meantime I will install the Polish emulator.

 

[smiffypr]

Hello,

Here a picture to confirm where these parts should be inserted:
I have remove the ring to show the location.
The small pin with the spring should be in the hole facing the big black pressure valve (at the top in this picture). The long small one in the other small hole.

I have just taken another unit apart and this is definitely correct. My theory is that the spring and nipple are a one-way valve so that when the brake lever is released the fluid is forced to return a different way, and I think this would be done in order to bleed through bubbles during the bleeding process, i.e. so bubbles didn't just move back and forth.

 

[SoCalLT]

Great info here, thanks everyone! I have just taken the abs unit out of my 03 LT, front system suspect with possible faulty motor according to diagnostic test. The filter was definitely very dirty.. as well as the reservoir for the front circuit. Does anyone have a diagram of which pins operate the motors? Would like to apply 12v to the front motor to see if it engages before I pull it apart.

 

[jzeiler]

Those pins are INSIDE the unit but are accessible without breaking any fluid paths. Just remove the cover next to the big connector and you will see the motor pins.

 

[SoCalLT]

Okay, thanks, can do.. just curious if anyone had traced those inside wires from the motors to the harness.

 

[jzeiler]

No the path from the connector does not go direct to the motors there are circuits that control them on the circuit board. You have to remove that cover and circuit board to get to the motors.

 

[SoCalLT]

Thanks for the reply John!! So I have the cover off.. I applied + to the red terminal and ground the black terminal and the motor does not run. Did the same for the rear motor and it runs fine. Electrical looks fine.. Looks like I'll be hunting for a motor..

 

[AntonLargiader]

I have motors but you may be able to open that one up and clean it out. Sometimes it’s the brushes, sometimes a seized pump, maybe something else but those are the common ones.

 

[SoCalLT]

Thanks Anton, I pulled the motor apart, it looked okay.. but the pump is seized, is that a doable project? I put that motor on the other side and it ran slow so I stopped it, took it apart again and noticed two broken wires...

 

[SoCalLT]

Anton, let me know how much you are selling the motor for. I disassembled the front circuit pump and was able to get that up and running with the other good motor. Looks like I should be good with just one motor. Thanks!

 

[SoCalLT]

Beginning the disassembly of the donor unit from an R1150.. Front circuit motor does not spin, rear circuit motor is fine. Will swap out the pump and motor from the rear to use on my front circuit. When taking apart the donor motor, there were small internal parts that came out(not entirely sure from where..) that I did not see in my unit... would that be normal between models(mine is the KLT)?

 

[jzeiler]

I have seen those in other units as well. Maybe yours were like these.

 

[SoCalLT]

Thanks John, very helpful, I'll look..

 

[Cefoul]

Hello,

John, the small part and the small spring are not located in the red circle of your picture. And the other parts in the red circle can't be removed without destroying the case. In fact this small pin and spring are hidden by an aluminium ring just behind the solenoid.
Here some pics if that can help:

 

[jzeiler]

Both those are used to press against the ball you see in the center, not sure how to hold them in place on reassembly.

 

[Cefoul]

Sorry John but none of them will press the center ball. The center ball is pressed only by the black piston. And the black piston is moved by the solenoid. But these 2 small parts are hidden in 2 small cavity behind the aluminum ring and altogether there are there to control the speed of the black piston and some kind of shortcut for the brake fluid. In my previous comment, in the second picture I have removed the ring and you can see the 2 small pieces partially out of their holes. the ring will keep them inside their holes and then you can insert the black piston and finally the solenoid over the piston.

 

[jzeiler]

That is good to know as I could not see how you could put them in line with the ball. This all makes more sense now thank you. I will up date my pictures to reflect that.

 

[SoCalLT]

That explains a lot Cefoul!! Thanks for posting the pictures! (I also went back and saw where you posted the pics on post #34) When I pulled the case apart on the donor, the o rings came out along with one of the washers which is why those small parts came out. On mine, the 0-rings stayed in, which is why I didn't see them come out. What a relief! Do I need to take those out to clean, or just reassemble?

 

[Cefoul]

For the "rubber" o-ring, I recommend to remove them and to attach them to the solenoid. To be sure there will be in the correct position.

It is always a matter of "how many time do you plan to open again this thing?".
On my device I had dismantle everything possible, cleaned all the parts, changed every single gasket and o-ring (EPDM and not NBR) and applied some silicone grease (special for brake parts) where needed.
This system needs a lot of care with the o-rings, the screen filters, the pressure sensors, the hydraulic pumps and the motors. Only the electronic mainboard doesn't require services (if there is no burn component).

But that's the way I use to do and I can't speak for others.
As long as I can found parts, I'm ready to do it again if my device fail in the future because I really like this assisted brake system and I can't imagine to bypass this set up.