ABS replacement

[JJDesign]

Morning, I have a r1200 gsa lc 2014 with the rear brake issue that has been discussed a lot. So I have changed the brake lines, about to put in a brand new M/C, since I put in a used one and not sure if the problem is that. I also got a second hand abs unit and will then change all, re bleed and see where I am.
Sorry for the waffle, but my questions are around the abs unit and getting bmw to configure /programme it;
1/ will it work before I get it linked by bmw on their computer and what will I see before I do get this sorted.
2/ I read somewhere that I can remove the black electrical part of the abs unit and swap my current one and this sorts out the bike recognising it and no bmw intervention needed. Is this true? And at the same time, can the problem be with the electrical part?
My bike loses rear brake very quickly, I have serviced the calliper, new seals and pads, both rear brake lines changed, but still air getting in and I’m pretty sure for the first time air bubble are coming back into the M/C whereas before I was getting micro bubbles at the calliper end when bleeding. I also do the abs bleed through the app, and that will also give me air. Normally it can be half a day before the brake goes ‘squishy’ and then gone, but a couple of days ago I had bled, weight overnight, very little pressure to put down when I went of, but it went within 10 minutes. I don’t mind a challenge but this is a hair pulling experience of trying to get this sorted
Any further advice/help on this would be gratefully appreciated., especially around the abs questions. Many thanks

 

[Santa-2512]

Coding will be for the electrical side (digital), coding has no impact or bearing on the mechanical side of things (analogue) - unless the digital side of things makes the mechanical side of stuff work

If your putting in a whole new ABS unit (inc electrical box), i believe it will need coding as its part of the LIN/Can bus system

(basically certian bits of bike info are stored in certain components for operational & security purposes) mix them up and the bikes ECU's may think the bike has been tampered with and throw error codes

Assuming you have all the air out of the system (fluid & bleeding) air can only get in / out via a hole , this could be a physical hole, or a poor seal (soft/ hard)

Have you tried flushing all fluid out of the brake system , and pulling a vaccum to see if anything shows up , if you cant pull a vacuum & hold it may help you find your leak

 

[JJDesign]

Coding will be for the electrical side (digital), coding has no impact or bearing on the mechanical side of things (analogue) - unless the digital side of things makes the mechanical side of stuff work

If your putting in a whole new ABS unit (inc electrical box), i believe it will need coding as its part of the LIN/Can bus system

(basically certian bits of bike info are stored in certain components for operational & security purposes) mix them up and the bikes ECU's may think the bike has been tampered with and throw error codes

Assuming you have all the air out of the system (fluid & bleeding) air can only get in / out via a hole , this could be a physical hole, or a poor seal (soft/ hard)

Have you tried flushing all fluid out of the brake system , and pulling a vaccum to see if anything shows up , if you cant pull a vacuum & hold it may help you find your leak

Hi, thanks for this, so does that mean if I keep my bikes electrical part and only change the metal abs part it should, in theory, then be ok and not need coding?
I’m hoping the air is the M/C, but I have read lots of different elements, including overheating, which I don’t think it would be as I have a new disc, serviced the calliper.
I’m going to bleed/flush both front and rear after new M/C and AB’s change over. Is the vacuum much better than a regular bleed, including the abs bleed?

 

[Santa-2512]

The brake system should be a sealed system, the only way air can get in. Is via a hole or from boiling the fluid. if you pull a vacuum or presurise se the system, you can use soapy water on every joint etc, you've done a lot of spending with little to show

 

[Santa-2512]

I'd hold of changing thecabs unit until you have confirmed the rest of the system ok

 

[JJDesign]

To be honest if I’m checking everything and that will include having the tank and air filter box off, I’m tempted just to do all and change the abs whilst accessible. I note there is a very extensive thread around the rear brake with a volume of possible solutions and currently I’m down to abs and m/c, which has been highlighted in forums as to where air and failure might be.
Can I ask if the changing over of the electrical part from my bike to the replacing abs unit will work and no coding would then be needed?

 

[JJDesign]

At the same time,since I’m waiting for a tool I’ll do what you suggested, I can bleed it quite quickly and then check the parts that are already accessible, then take tank and air filter box of and do a check before putting the abs and m/c on, sensible suggestion before all hair is pulled out!

 

[theoneandonly]

remove the abs system.

but keep the electrics ? it may power traction control , if you have that .

 

[JJDesign]

remove the abs system.

but keep the electrics ? it may power traction control , if you have that .

Not removing the abs

 

[DJ123]

To be honest if I’m checking everything and that will include having the tank and air filter box off, I’m tempted just to do all and change the abs whilst accessible. I note there is a very extensive thread around the rear brake with a volume of possible solutions and currently I’m down to abs and m/c, which has been highlighted in forums as to where air and failure might be.
Can I ask if the changing over of the electrical part from my bike to the replacing abs unit will work and no coding would then be needed?

In less than half an hour you can have the whole front apart quite easily. (body work, airbox, fuel tank, crash bars, etc).

 

[JJDesign]

In less than half an hour you can have the whole front apart quite easily. (body work, airbox, fuel tank, crash bars, etc).

I’ve already been there when I replaced the rear brake lines. Could do with advice on the abs element and any ideas around the rear brake solutions though

 

[Spooky]

If you’re getting micro bubbles when bleeding, it’s possible air is getting past the threads on the bleed nipple. If your catch can is below the height of the abs module those micro air bubbles can syphon back up the pipe into the system. You could try a re bleed with the catch can higher up so any air getting in will hopefully rise to the catch can and not the brake system. My old Aprilia used to need its caliper raised above the m/c height or it would never bleed properly, so rear brakes can be tricky.

 

[JJDesign]

If you’re getting micro bubbles when bleeding, it’s possible air is getting past the threads on the bleed nipple. If your catch can is below the height of the abs module those micro air bubbles can syphon back up the pipe into the system. You could try a re bleed with the catch can higher up so any air getting in will hopefully rise to the catch can and not the brake system. My old Aprilia used to need its caliper raised above the m/c height or it would never bleed properly, so rear brakes can be tricky.

BMW bled it a couple of times with original bleed nipple, still went in a day, have a stahlbus bleeder on now and same. Will check again, but unfortunately it’s probably not that. I’m hoping it’s the M/C to be honest.
Have heard about raising the calliper higher to help get air out, so that is another ‘thing’ I’ll do.

 

[theoneandonly]

if you think it is the master , blank it off and test in isolation.
or rig up a separate line to a caliper and test.