Author Topic: Brake bleed  (Read 6237 times)

Offline gazman

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Brake bleed
« on: February 14, 2015, 08:33:43 PM »
Greeting,s all  I,m wanting to replace  my brake fluid. how long its been in there only the bike knows (an she aint sayin) anyway I,ve bled lots of brakes in my time but never an ABS system. mine is K1100 ABS1 is it as straight forward as bleed the modulator first then the caliper or is there some trickiness involved. thanks in advance. :mm :bmwsmile
  • west australia
  • 93 K1100LT

Offline WayneDW

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Re: Brake bleed
« Reply #1 on: February 14, 2015, 08:45:56 PM »
I didn't have any problem.  But I think the vacuum brake bleeder probably helped.
  • Minneapolis, MN, USA
  • 1992 K75RT

Offline johnny

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Re: Brake bleed
« Reply #2 on: February 14, 2015, 09:05:17 PM »
greetings...

lotts of motobrikers use a hand vac... some use a power vac... i have a hand operated brake vac... butts since their aint much fluid in there i do it the old way...

11mm on the nipple... clear vinyl tube on the nipple cinched down with a ziptie... other end through a hole in a coke bottle cap...

front abs... take it slow... open nipple... slowly pull in lever... slowly slowly slowly... tighten nipple and release lever... repeat till fluid runs clear... keep the master full... then the left caliper... then the right caliper... and before buttoning it up... the left caliper again...

rear abs... take it slow... open nipple... slowly push down pedal... slowly slowly slowly... tighten nipple and release pedal... repeat till fluid runs clear... keep the master full... then the caliper...

will take a half an hour... should end up with a half full coke bottle of nasty fluid and an empty new brake fluid bottle...

slow slow slow is the key... the front will choot out fluid if you donts go slow...

j o


  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny
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Offline gazman

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Re: Brake bleed
« Reply #3 on: February 14, 2015, 10:03:20 PM »
Thanks guys
  • west australia
  • 93 K1100LT

Offline gazman

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Re: Brake bleed
« Reply #4 on: February 15, 2015, 12:27:50 AM »
Hmmm well bled rear no probs, but started on front modulator first crack of nipple small amount of fluid moved then nothing. No fluid movement at all, no pressure at lever, nothing. Brake lines look like originals and I,ve read how they can deteriorate internally me got the vibe that's  what goin on. question is where do I go from here, replace all the lines an start again. Ideas?
  • west australia
  • 93 K1100LT

Offline gazman

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Re: Brake bleed
« Reply #5 on: February 15, 2015, 12:41:49 AM »
Not so sure about the line blockage now. Removed line from master cylinder, pulled lever in. . . . nothing no fluid at all. Now I,m thinkin (A) new master (B) should have left it alone. No ride for Gaz tomorrow back to work Tues for 2 weeks. Boohoo :dunno :dunno
  • west australia
  • 93 K1100LT

Offline gazman

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Re: Brake bleed
« Reply #6 on: February 15, 2015, 07:04:55 AM »
So anyways walked away for a few hours. went back pulled master apart and discovered piston stuck at bottom of cylinder after much persuading managed to get it out. Bore looks good (no pitting or scratches) seals look ok. thinking good clean, reassemble, bleed and yeehaa Gaz gets another ride in before work.  PS thank you Jonny an the boys for all your efforts to make this such a great site :riding:
  • west australia
  • 93 K1100LT

Offline johnthehedger

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Re: Brake bleed
« Reply #7 on: February 17, 2015, 03:17:27 PM »
Johnny...........I enjoy reading your posts. Very informative. I have one question before I bleed mine (K1100) - does the ABS unit itself need bleeding?
John

K1100LT - 1996
Yamaha XJ900S Diversion - 1999
R100RT (awaiting restoration) - 1979

Offline johnny

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Re: Brake bleed
« Reply #8 on: February 17, 2015, 03:24:49 PM »
yesser... the front bleed nipple is the back abs... the back bleed nipple is the front abs... abs 1st then calipers...

j o
  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny

Offline johnthehedger

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Re: Brake bleed
« Reply #9 on: February 18, 2015, 12:34:23 PM »
Thanks for that info Johnny
John

K1100LT - 1996
Yamaha XJ900S Diversion - 1999
R100RT (awaiting restoration) - 1979

Offline bilgolabeach

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Re: Brake bleed
« Reply #10 on: February 09, 2018, 05:46:52 AM »
Hi. Just wanting to bleed the brakes on my Aussie supplied Ex Police 1999 K1100R/T. All the above is good, but the RH front caliper has some weird sort of bleed nipple that involves a big cylindrical alloy block with a grub screw in it. If I remove the grub screw and pull the lever, no fluid comes out. The ally block doesn't want to be unscrewed. Can anyone tell me how to deal with this?
  • NSW Australia
  • BMW K1100LT, Kawasaki ZRX1200s, BMW R110/7 V8

Offline Laitch

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Re: Brake bleed
« Reply #11 on: February 09, 2018, 10:39:34 AM »
Hi. Just wanting to bleed the brakes on my Aussie supplied Ex Police 1999 K1100R/T. All the above is good, but the RH front caliper has some weird sort of bleed nipple that involves a big cylindrical alloy block with a grub screw in it. If I remove the grub screw and pull the lever, no fluid comes out. The ally block doesn't want to be unscrewed. Can anyone tell me how to deal with this?
Post a photo of the offending part.
  • Along the Ridley in Vermont.
  • 1995 K75 72,000 miles
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Offline Inge K.

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Re: Brake bleed
« Reply #12 on: February 09, 2018, 11:27:30 AM »
the RH front caliper has some weird sort of bleed nipple that involves a big cylindrical alloy block with a grub screw in it. If I remove the grub screw and pull the lever, no fluid comes out.

It's a check valve which is used on the factory when they fill the system.
Normally it shouldn't be a problem to unscrew it and change it out with a normal bleed nipple.
Loctite is used, the type which can be unscrewed with ordinary hand tools.

But the recommendation from BMW is that you undo the grub screw and mount a bleed nipple.
Bleed the brakes as normal, afterwards remove the bleed nipple and put back the grub screw.
  • Norway

Offline bilgolabeach

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Re: Brake bleed
« Reply #13 on: February 09, 2018, 11:37:41 PM »
thanks Inge K. That sounds good, but when I remove the grubscrew, and pull the lever, no fluid comes out. Does that mean that the checkvalve is jammed? Malcolm
  • NSW Australia
  • BMW K1100LT, Kawasaki ZRX1200s, BMW R110/7 V8

Offline Laitch

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Re: Brake bleed
« Reply #14 on: February 10, 2018, 12:17:56 AM »
Does that mean that the checkvalve is jammed?
I think it means things are ok, Malcolm. That unit would seem to be the check valve and it is stopping (checking) fluid flow. That's why no fluid leaves when that grub screw is removed from it. You either need to have a factory bleed screw designed for this check valve to accomplish bleeding—description is in this document from the MAX BMW fiche—or remove the whole check valve and replace it with a standard bleed bleed valve. Heating the check valve a little with a heat gun should allow release of the Locktite gripping it. First though, you need to decide which method you intend to use for bleeding and have the corresponding part or parts ready to install for the job.
  • Along the Ridley in Vermont.
  • 1995 K75 72,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline Inge K.

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Re: Brake bleed
« Reply #15 on: February 10, 2018, 04:47:19 AM »
but when I remove the grubscrew, and pull the lever, no fluid comes out. Does that mean that the checkvalve is jammed?

As mentioned in my previous post you must mount a bleed nipple where the grub screw have been.
When you mount the bleed screw, it will open the check valve.....see the PDF which Laitch provided.

It's a standard bleed screw that you need, just like the one you have on the LHS...I would guess it's
M10 x 1.0 which is the threads mostly used by BMW in brake applications...measure the grub screw.
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Offline bilgolabeach

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Re: Brake bleed
« Reply #16 on: February 11, 2018, 03:51:05 AM »
fantastic, makes perfect sense. thanks
  • NSW Australia
  • BMW K1100LT, Kawasaki ZRX1200s, BMW R110/7 V8

Offline bilgolabeach

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Re: Brake bleed
« Reply #17 on: June 10, 2018, 08:30:04 AM »
Hi, can anyone tell me what this switch is for on my ex Police K1100R/T-P? It doesn't seem to do anything.
And, is there a switch for putting the parking lights on/off without the ignition on? They come on with the ingnition (likewise the headlight),
but I can't see how to switch them on as parking lights only.
Sorry, I know this should be a new post, but couldn't figure out how to do that.
  • NSW Australia
  • BMW K1100LT, Kawasaki ZRX1200s, BMW R110/7 V8

Offline bilgolabeach

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Re: Brake bleed
« Reply #18 on: June 10, 2018, 08:48:21 AM »
thanks, but that the best drawing I can do.
that's the image of what's on the rocker switch on the handlebar mounted dash panel.
any clues?
and thanks, I'll try using the ignition switch to get the parkers to work.
  • NSW Australia
  • BMW K1100LT, Kawasaki ZRX1200s, BMW R110/7 V8

Offline gazman

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Re: Brake bleed
« Reply #19 on: June 10, 2018, 10:22:38 AM »
Mate if it's an ex cop bike, , , , maybe it was for the flashing blue that we all hate seeing in the mirror?
  • west australia
  • 93 K1100LT

Offline SinNH

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Re: Brake bleed/change
« Reply #20 on: July 17, 2019, 02:51:48 PM »
I know, year old thread, but relevant for my issue because I have the same problem as gasman had. 93 w/ABS I, rear mod first and then caliper, went fine.
Front modulator wouldn't give a drop, even with max vacuum ( usually use about 50% vac at the most ) so I did the calipers, went fine, three reservoirs each and back to the modulator still nothing. Thanks ahead for any  ideas.
PS brakes felt fine before starting fluid change, same set-up as my  RT, and now in the shop the front lever feels normal after fluid change.
And, seems funny to me that the input line from the lever/reservoir connects on the mod on the bottom port below the bleed nipple and the output line just above, and yet I can bleed the calipers, but not the nipple 20 mm above.
The bleed nipple threads into a reducing bushing or some sort. Anyone opened that up ?                   
  • NH
  • 93 K1100 LTA greenish

Offline johnny

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Re: Brake bleed
« Reply #21 on: September 02, 2019, 10:13:05 AM »

* grubscrewit.png (173.71 kB . 588x493 - viewed 75 times)
  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny

Offline volador

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Re: Brake bleed
« Reply #22 on: September 02, 2019, 10:59:55 PM »

* grubscrewit.png (173.71 kB . 588x493 - viewed 75 times)

Nice Shirt! When are these available for subscribers?
  • NYC
  • 1991 K100RS 1993 K75S ABS
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