R1150R BMW Integral ABS 1 (iABS1) Removal

[sweatmark]

Completed most everything for the ABS-ectomy this past weekend.

Album within PhotoBucket:
http://s74.photobucket.com/albums/i269/ ... ABSectomy/

<edit 2011 - deleted slideshow; easier to access pics within photobucket album>

Notes from the process:

• missing/damaged tab at RHS side panel rear and damaged lower screw insert
  the banjo bolt is NOT Torx but soft
  part numbers for bleed & cap, separate and combined
  fuel quick-connect "issues"
  speedometer does not work yet
  "brake failure" lamp lit irony
  ABS brake switches and 5-pin relay WORKS!
  definitely easier to cut the ABS wiring harness than find mating piece, pins/sockets, special crimp, more wire
  ABS harness wires not long enough for fuse box run
  ABS harness covering is tough and pesky
  read the fine print on relay body for pin assignments
  brake pressure fitting too long for non-ABS junction piece?
  bleeding front brakes is a pain
  rear brake with ABS master cylinder works OK
  nice to hear silence instead of ABS whine
  bike handles better: actual ABS component weight = 10+ lb.
  should have detached rear brake master assembly for easier access and spill control
  fluid within ABS module nasty, flushed with new DOT4

The ABS removal process is easy. I went slow, spent too much time wiping up brake fluid drips and splashes, and made a few mistakes, but it's not rocket science.

Remaining problems - speedometer drive for the Rockster ABS implementation, ironic Brake Failure idiot lamp.
But result is good: the brake switch/5-pin relay idea works, and test ride last nights showed how responsive the R1150R can be without extra mass located above the center of gravity, with the good braking performance enjoyed on our non-ABS Roadster.

[iowabeakster]

Thanks for the excellent photos.

The rear brakes attach to the master cylinder with the stock brake line and banjo? So, the only needed hardware is new crush washers (just the rear)?

Can you you take care of the brake warning light just by removing the dummy bulb?

The drawback is you wouldn't get the warning if the tail/brake bulb burned out, but it would get rid of the annoying dummy light.

[mhsilverw]

The pics and details are great.

Hope you find a way to 'bypass' or getround the speedo sensor problems....as you have found a way around the other scary electics hopefully you will master this too.

Mark

[sweatmark]

I replaced the rear banjo bolt because it was soft - my correct Metric hex spun in the bolt but a Torx driver pulled the bolt out. The new banjp bolt in the front brake line junction piece was deemed necessary because of the (lack of) depth of the junction compared with the OE pressure bleeder check valave fitting. Comparison of banjo with pressure bleeder fitting made me nervous about threading the check valve too far into soft alloy.

I'll figure out a way to address the "Brake Failure" lamp, because i want to use the indicator for something else. The tail/brake lamp current sensor is part of the ABS computer, so lamp failure is now assessed by that old MSF course pre-ride process we all learned long ago.

The speedo drive circuit might take a bit more work, but I've got a couple of quick ideas to try this coming weekend, plus a more sophisticated solution that could add bonus points. Thank goodness for Google and broadband here in the vacation spot.

[sweatmark]

OK - brought my ABS project file along on vacation this week, chock full of useless & useful info.

In the useful category, the ABS wiring schematic from BMW CD-rom show the brake system warning lights wired as:

(a) one dummy light is powered through the ABS wiring connector; since it's now disconnected, I'll assume that's a nonissue.

(b) the other dummy light is powered through the ABS relay (K9197), with relay coil's ground connected through the ABS connector; that's gotta be the lamp that's now ironically light following the removal of my ABS module, and I'll further guess that the relay is an NC-type, defaulting to power supply to load when the coil is unpowered... which would explain the "Brake Failure" lamp shining defiantly on an ABS-ectomized R1150R, like the ghostly twitch is a severed frog's leg.

So, the lamp should "shut up" when I pull the relay, or if the coil is grounded. Will try both and report back.

That same BMW schematic is useless WRT any signal processing that happens between Hall sensor at rear wheel and the signal input to the speedometer. Two experiments are forthcoming: (1) hooking up the Hall sensor as suggested by sensor mfr. tech info, and crossing fingers that speedometer doesn't get zapped; and (2) using a chip designed to drive and condition the 2-wire Hall sensors that are used on the BMW bikes.

Has anyone created a quick custom circuit board for this type of application? If so, then suggested resources?

[sweatmark]

<edit 2011 - unnecessary>

[sweatmark]

OK - the ABS warning light "Brake Failure" was easily addressed by pulling the ABS warning light flasher relay, as described above. The blue relay's schematic (found on side of relay case) confirms that the circuit is normally latched or closed without coil power.

LIGHT = ON


LIGHT = OFF


Hope to have time tonight to wire up a speedo fix attempt for test ride.

[sweatmark]

Well, speedometer wiring attempt #2 failed. I need an oscilloscope, speedometer input signal specifications, and a clue about Hall sensor circuit design. My hack circuit could be bogus or I failed to connect the wires as required. For instance, I'm guessing that the Hall switch's black/brown and speedo's blue/brown wires are ground references, but that's a "groundless" assumption.

Contacted a local electronics dealer regarding the 2-wire Hall sensor support chip from Maxima. Hoping this option sees the light of day. I'll go back under the tank when time permits to confirm some basics, maybe try a slight variation for the Hall sensor circuit.

[sweatmark]

Update:

(1) The Rockster's "new" non-ABS brakes are working great. Another brake bleed will cure any squish remaining in the front brakes.

(2) Brake & tail lamp actuation using the 5-pin relay connected to ABS-spec brake switches is also a success. Very simple and inexpensive to implement.

(3) For the Rockster, like certain R1100S and K1200RS models, the rear wheel Hall or proximity switch signal that the ABS computer sends along to speedometer remains the only challenge; I'm confident that a solution to the problem will emerge. For ABS R1150** bikes other than these, the speedo signal comes from a drive unit located on the front axle, with some associated wheel hardware differences.

(4) Originally I'd thought it would be cool to source the mating electrical connector for the BMW ABS system, inorder to make the electrical aftermath of the ABS removal even more "plug & play". This morning Tyco/AMP responded to my inquiry about the needed connector parts with the following:

Subject
Connector details needed PN AMP 968437

Discussion Thread
Response (Larry L.) 07/21/2008 09:16 AM
This part and the mate is restricted.

Customer (Mark) 07/05/2008 01:14 PM
Hi - What is the pin layout of AMP 968437 and part numbers for mating connector and male pins? Also need availability of the mating parts in small quanitities. Thanks!

Something along the lines of "restricted" was my original guess, but now we know.

[sweatmark]

<edit 2012 - speedometer fix info moved to other topic thread>

[sweatmark]

<edit 2011 - superfluous>

[chopper_harris]

Oh, don't forget to tell your insurance company that you have butchered your bike.

They will want full details, and will be particularly interested in the lack of ABS - expect your premiums to go up


We have a saying here in the UK - "you should get out more". Think about what else you could have achieved in the time you have burned on this project.

[sweatmark]

If you're the real Ron Harris, then we're happy to have you here on the R1150R board. As a long-time defender myself with reputation for solid tackling, who watched you play on Public Broadcasting coverage of 70's English League play, I'm especially honored to receive your message board ridicule.

But if you're not the authentic Chelsea legend, then let me mention a saying we have here in the USA: "whatever..."

=======

Just to bump the ABS thread, my speedometer fix is - well - not fixed. The op amp signal boost using bike's unfiltered/unregulated power to supply both the amp and the rear wheel Hall sensor results is speedo behavior that mimics the tach. Part of the problem might be due to overvoltage of the RMS input to speedo: it really wants <5Vdc and is currently getting a bit more. A quick test using 9 volt battery as supply might help.

Note - turns out the "speedo as tacho" results in odometer operation that's not too far from actual, based on GPS data. During a 1k mile trip over Labor Day weekend, the funky odometer (measuring "miles" of RPMs) was only 10% low compared to GPS mile acrued during a trip with good mix of highway and mountain road riding.

Good news is that braking performance - especially front end feel and modulation - is vastly improved without iABS. I can finally feel front tire bite and feedback on the Rockster similar to my track bike. And 2k+ miles on the brake switch/lamp setup have proven it to work reliably.

[Phang]

part numbers for bleed & cap, separate and combined

Hi sweatmark, I am planning to do the same to my Roadster before the servo fails. I managed to figure out most of the part numbers that I will required to order the parts. However, the part number of the bleeder screw and rubber cap got me confused.

I found 2 set of part numbers from a few online part fiches.

34211236793 - vent screw
34327666398 - ventilation bolt

34211236794 - dust cap
34327666399 – cap

I guess 34211236793 and 34211236794 are the correct part numbers judging from your photo in the earlier page. If you could kindly shed some light on this, it would be very much appreciated

[sweatmark]

phang,

Originally I did a "One of each, please!" order for the new fittings, and found that there is potential duplication in the following parts:

34 21 1 236 793 - single bleed screw
34 21 1 236 794 - bleed screw cap
AND I received another #793 that contained both the bleed screw and cap!

PM me with your e-mail and I will send you the large format photos of the BMW parts in original packages (with parts number designations). Might make it simpler to bring the photo for ordering, as it helps prove the case of what physical part corresponds to which part number.

[Phang]

Thanks for the help sweatmark, PM sent. Anyway, my email is clphang @ hot mail dot com

Cheers,
Phang

[sweatmark]

Received a couple ABS brake questions via IM here this week, and figured I'd bump this thread back to life.

FWIW - Rode a couple good weekend trips towards end of the 2008 season, including favorite roads in Northern California that are typically ridden aggressively. The un-ABS'd Rockster was much more fun to ride in NorCal with the absence of power-braking servo surge; the comparison is especially noticable in late- or trail braking. I've had no problems with braking performance following ABS removal, and the relay circuit handling brake lamp duties via the OE (ABS-spec) brake switches has worked flawlessly.

Can't say the same for the speedometer, which turns out to mimic the tach right now via incorrect wiring and noisy rear wheel sensor power supply. I've got the parts to try another fix - which this update is intended to motivate.

Has anyone here put together a good pressure (not vacuum) brake bleeding system? Pressure bleed setup is my next great brake system (and hydraulic servo clutch) adventure.

[bikermeow]

HIya, anyone has the part number for a non-ABS rear brake switch (part No. 15)? It's funny but although the part is shown in the diagrams, there is no part number!



Cheers

[Phang]

Meow,

The part number for the non-servo rear brake switch is:

61311459747

Just in case you need it too, the part number for the non-servo front brake switch is:

61312305729

These are the normal NO (normally open) type of microswitch.

They are listed under the “Various Switches” section of the parts diagram, took me a few sleepless nights to figure it out. You owe me a cup of tea on Monday

[sweatmark]

Phang,

Thanks for posting the switch info.

I should reiterate that it is NOT necessary to swap the ABS-spec brake switches for non-ABS switches. Saves $100+.