K75 ABS Brake Bleed Issue

[frankenduck]

While well aware that we’ve long ago left the original poster’s question, dare I ask if we can turn the ABS off on these bikes? The “ABS” button - is that only to stop the flashing when there’s a fault code, or does it also (if temporarily) turn off ABS?

As mentioned, the factory ABS switch is only used for getting the light to stop flashing when in fault mode or it can be used for ABS resets.

However you can add a switch to cut power to the ABS brain that will turn the ABS off.  Put the switch in the green wire from ignition that powers the ABS brain. On 2V bikes the green wire goes to Pin 15. On 4V bikes Pin 16. (I've confirmed this with Tosi in Japan who is an ABS god.)

[Laitch]

However you can add a switch to cut power to the ABS brain that will turn the ABS off.

Do you intend to do that, or are you satisfied with the ignition off-sphincter clench method which is also recognized by doctors as being beneficial for prostate health?

[Past-my-Prime]

Can anyone report why the instructions are so clearly in favour of only letting the dealer flush the brakes? Is this a liability issue or are we anticipated to be pure idiots, unable to prevent air intrusion into the system? Or is there some secret technique, only known to them, to do this properly?
Curious minds, curious minds.

[Laitch]

Can anyone report why the instructions are so clearly in favour of only letting the dealer flush the brakes?

Service departments are a major source of income for dealerships so BMW supports them by recommending their usage by Beemer owners. We already know from our reading on forums that brakes can be neglected until water in their fluid corrodes master cylinders, and hoses are uninspected until they clog solidly. It doesn't take idiocy to screw up brake service; it just takes distraction, misunderstanding, and a lapse in maintaining clean working conditions. Once the principles are understood, maintaining good brake function is not too complicated to master.

Certainly in litigious America, BMW's telling Bubba "Sure, go ahead and fix 'em" would be incautious, so Clymer and Haynes take up the slack. Afterall, there's money to be made!
 

[frankenduck]

Can anyone report why the instructions are so clearly in favour of only letting the dealer flush the brakes?

Service revenue as Laitch points out.

It's just a guess but perhaps they modulate the ABS while doing the bleed.

But in all my years on Internet forums I've never heard of ABS or brake failures by anyone who does their own ABS bleeding.

[rocketbrick]

Alright gang, new stainless lines from motobins are on there. I tightened all the primary and secondary fittings on the brake lines, and I'm currently in the process of refilling the system. Also rebuilt the front calipers.

I'm having a hell of a time bleeding anything. I have the bars turned fully to the left, and am continuously pumping the brakes to eliminate all bubbles in the reservoir. Any tips? I'm thinking of letting it gravity bleed overnight.

I also have a Motive power bleeder. I'm trying to suck the fluid out from the ABS module, but it seems to be reintroducing air into the system. This will be my first time using a vacuum bleeder, so if anyone has some good video recs please lmk!

I'll send pics or videos on request. Thanks for willing to help me out through this y'all!

[Laitch]

Have you watched any of these?

[Bmwsquirl]

Rb

start with the caliper furthest from the master cylinder,then the one closest to the Mac
I found a place to by bed no parts for a really good price.I got three 38mm caliper rebuild kits for thirty dollars.really.got a brand new 12mm master cylinder with everything included for seventy dollars.
Www.oppracing.com their in Blaine washington.hope this helps
Be safe
Squirrel

[rocketbrick]

Have you watched any of these?

I have watched quite a few! I haven't found any adapters that fit a reservoir on the K75, however. I tried to bleed from the bleeder bolt on the front ABS module but that only made fluid shoot out of my reservoir

Reason I ask if because I heard people say you could reverse bleed the way that I mentioned above. I have a redneck engineered fitting that I use for such a thing.

[frankenduck]

Gravity can be your friend or your enemy. The "hump" between the front modulator and calipers can trap air.

What I do with ABS front calipers is remove them and use a piece of string to hang them from the garage rafters as high as possible so that air in the new brake lines will rise to the calipers to be bled out.

This isn't an issue when just bleeding but when installing new lines they start out filled with air.

Not the greatest picture but here's how I bled the front brakes of an ABS K1100RS when installing new lines:

[rocketbrick]

I'm good - got brake pressure and everything is working! Also, we're stopping, which is the most important part.

Thanks everyone for the help!

[Laitch]

 

[The Mighty Gryphon]

Can you tell us what you did to get them working?

[stokester]

Can you tell us what you did to get them working?

Please do.
I have both a Motive pressure bleeder with GM and VW MC adapters and a Snap-On vacuum bleeder which I used while working at Chevy shop and now on all my bikes and vehicles.

At a minimum I flush my braking systems every two years in both bikes and cages.  With a good vacuum bleeder it only takes a few hours on the cages and much less than that on the bikes.  It is inexpensive insurance against corrosion-related issues with master cylinders, calipers and ABS pumps.

That being said I have never had an issue with bleeding my two K75Ss, both with ABS, using the vacuum bleeder.