R1150GS ABS fault sorted...

Paul Young

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OMG!! I don't believe it but I've had a plunger test failure issue for some time on my 1150. You know the one... Pull away, & get a louder & more metallic kerplunk than usual, followed by alternate flashing abs lights. I even had it looked at by Roy Gardner who cleared the faults & reset everything only to get the same horrid, loud kerklank sound that is the tell-tale abs plunger test failure.

So, I figured I had nothing to lose by having a poke around &, armed with the advrider write-up from Terry (huge thanks for the detailed write-up HERE) I set about taking the abs modulator apart.

I didn't need to take the unit off the bike, just removed the tank to access the top of the hydraulics. Sensors & gaps had already been checked, so I didn't do anything else with the electrics, just the hydraulics. I removed the top of each circuit (standard 22mm socket) starting with the front, which is on the right hand side if sitting on the bike & facing forwards. I cleaned out loads of crappy gunge around the top of each plunger, removed the ball bearing & it's seat. Then I took a few cotton buds dipped in fresh hydraulic fluid & cleaned the bore that the plunger sits in. There was all sorts of gunge & small particles in there which must have built up over the years, despite regularly changing the brake fluid. Once it was all cleared out, I put the plungers back in with a smearing of fresh brake fluid, did the same with the cleaned-up ball bearing seats & ball bearings, followed by the cleaned-up tops, fresh brake fluid applied to the o-rings, etc.

It needed a lot of new brake fluid to bleed everything through - both circuits in the abs modulator, followed by all three calipers. Last thing to do was the abs reset procedure (details here) followed by a test ride. Hallelujah...!! Ignition on & I had the simultaneously flashing abs lights, followed by the sweet sound of a normal abs test as I pulled away, followed by perfect abs operation when I carefully :rolleyes: stamped on the rear brake. Front brake test had the same perfect result.

The whole procedure took me a steady hour & a half to complete & was an awful lot easier to do than I'd ever imagined. Worth a try if you've had a plunger problem, & I hope you're as lucky as I've been... :thumb2
 
thank you for posting this,very interesting,cheers,I was under the impression that there was not much zou could do,at least for one problem there is a remedy.Iam sure you have just saved some people a lot of money
 
Great post, surely worthy of a FOAW sticky :thumb2

My '05 servos/abs haven't caused me a moment of grief, but I expect it to happen one day.....stuff like this is gold to have stashed away :clap
 
Just spotted this.. Have the same problem. Friday, stopped at lights and heavy 'kerplunk' as I take off followed by intermittent flashing lights. No ABS since..:mad:..63k miles on bike. Time to take the spanners out I guess.
 
Another successful one here, quick strip down and clean up with some cotton buds and miraculously it worked! :beerjug:
 
I had exactly the same problem and did the same procedure after the encouraging tale on the Adv Wisdom article.
http://advwisdom.hogranch.com/Wisdom/BMW ABS II D&A.pdf
I had even lightly sanded and polished each plunger.

Worked a treat....................for a while.

Then the problem resurfaced and never went away. I finally took the bulbs out from the cockpit and rode ABS-less.

Not wanting to accept defeat and after some surfing, had the ABS unit disassembled (with the chip intact to avoid recoding) and sent it to Module Masters for a rebuild, located in the US of A in a town called Moscow.

It now works as it should......so far.

Not to burst your bubble, but it may not just be the plunger getting 'stuck' but weak electricals that is supposed to work the gear motor.
 
ABS (again)

Coming into this somewhat late but can the OP please advise how he removed the plungers.
I can remove the top of each cylinder on the ABS unit, together with the spring, ball bearing and
seal ring but nothing else will move. Obviously I don't want to damage anything by prying too
hard so I would be grateful for any help.

Thanks

Slalom
 
I did this for the rear piston on mine, and it pulled up ok, using long-nosed pliers in the central peg, after removing the filter/seal etc.
The piston has an o-ring seal on it, so possibly that has stuck?
 
OK> Thanks for that. Not sure what you mean by 'peg', but I can feel a ridge inside the top of the piston.
I'll give it a bit more heave ho t/morrow.
The really stupid thing about this is I had the pistons out a few years ago and don't remember any difficulty
then!!
 
Peg

This is an extracted photo from the procedure on ADVRider.com, which shows the peg on the top of the piston.
 

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I suspect you're still looking at the filter that sits above the piston and needs a little bit of persuasion to pop out. Then its the view in the picture above ^^^^ and needle nosed pliers work a treat.
 
.

Bizarrely ive just put my bike on a tester and it said faulty piston..think ill be trying this fix. cheers
 
The link to the detailed article on ADV doesn't seem to be working, does anyone have an up to date link to it?

Sent from my GT-I9505 using Tapatalk
 
Thanks for your help guys - going back in to battle now.

No, I couldn't get the link advrider to work either.

Cheers
 
That worked well then!! Plungers out of ABS unit, all pristine and clear, seals good, washed in clean fluid anyway, re-assembled
with care, new Dot 4 in whole system and ABS re-set. Eureka!! ABS lights flashing together - job done.

Ride away, 3 yards, clunkity click squeak ----- lights flashing alternately. Not pleased at all really!!! Brakes work fine.

Any ideas guys?

P.S. Thanks for the Av rider link. I'll check it out, not tonight though.
 
That worked well then!! Plungers out of ABS unit, all pristine and clear, seals good, washed in clean fluid anyway, re-assembled
with care, new Dot 4 in whole system and ABS re-set. Eureka!! ABS lights flashing together - job done.

Ride away, 3 yards, clunkity click squeak ----- lights flashing alternately. Not pleased at all really!!! Brakes work fine.

Any ideas guys?




P.S. Thanks for the Av rider link. I'll check it out, not tonight though.

I realise that this is an old post but Slaloms issues replicate mine and I wondered if and how he had resolved them.

Summary: Bought my 2000 BMW R1150GS with the front brakes disconnected from the modulator and linked directly to the master cylinder. rear brake still routed through the ABS pump and indicator bulbs removed from the dash panel. I replaced the bulbs, checked wheel sensor gaps, cleaned out the ABS pump pistons, reconnected the front brakes to the ABS pump, flushed everything through and reset the ABS ecu to get simultaneous flashing lights at ignition on.
Set off down the road and after 3 seconds clunk and back to alternate flashing lights on the dash. With no access to a GS911 and in an effort to diagnose the specific problem, I bought a diagnostic cable connector, OBDlink MX adapter and Motoscan app (basic). The APP connects to my engine and ABS ECU's and with ignition on will read my engine ECU information but not the ABS one. So I'm no further forward and I don't know how to check that the wheel sensors are working or if its a fault in the ABS pump itself. Any thoughts?
 
Hi again,
Yep, gave up at that stage and took it to Steptoe who, in an earlier reply to another Tosser with problems, said he had never had to change a non servo abs unit yet, did a diagnostic
test and said the best thing I could do would be to pick up a secondhand unit and fit that. Great help!!! Part exchanged it for a VStrom 650, which is fine apart from chain drive and
wind noise. Still lust after a GS though.
slalom
 


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