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The story behind the broken front & rear brake light switches on BMW Motorcycles
ALSO:  stiff throttles, on ONLY 1985 K bikes

brakeswitches.htm-37B
Copyright, 2012, R. Fleischer



This article is not concerned with the hydraulic pressure activated brake switches.   Those switches, originally 34-31-1-233-959, were replaced with 61-31-1-244-334, and you can probably substitute the switch used on old VW Beetles.  Napa carries that switch as number SL143.
There are other such switches:
3 terminal version is NAPA SL159, VW 113945515G; 2 terminal version is NAPA SL147, VW 0344004003

 

Some BMW Service Information Bulletins were issued regarding the front and rear brake light switches, brake lever, etc.   The bulletins applied to both Classic K bikes and also to Airheads, but not exactly the same way.   There were bulletins issued in 1987 and updated in 1988 and a formal recall in 1989.   Each one of these bulletins got longer, with more details.   All R series bikes FROM 1985 model year through 1988, and SOME 1989 airheads, were affected.  ALL models of airheads!

Federal Recall Campaigns NEVER expire!....if your bike has a problem, BMW dealerships will fix it, if it is in the Recalled Group, for free.

The SI's involved are 61 014 87 (2263) covering ALL models; 61 017 88 (2305); 2342; 2343.  This all became a formal FEDERAL recall campaign (see 2342),......and as such, if it applies to your bike, and you have the switch contacting problem...it will be handled totally by your dealer at no cost to you. 

Here is the Bulletin:  https://www.bmwmc.net/catalog/05.pdf

SI 61 014 87 (2263) came out in August of 1987 and covered ALL BMW models.  It said that rear brake light switch  on K models (61-31-1-459-588) and 61-31-1-459-569 front and rear brake light switches , except R80G/S, are replacing old part 61-31-1-459-519.  The SI explained that the -588 switch, on K models, can be used in place of the plunger switch if it utilized the solid mount type of foot rest plate, which has an extra casting rib and a mounting hole.  That -588 switch was introduced in the 1987 production year.  The switch is to be mounted so the switch mounting plate is resting against the cast rib, and is positioned correctly when there is a slight gap between the levering tab and the foot rest plate, and a click is heard when the foot brake pedal is depressed.
The -569 assembly replaces the -519, used as a front brake light switch, a clutch safety switch, and a choke light switch.
On the R bikes, the new -569 switch can be used at both front and rear brake light switches and clutch safety switch (except the R80GS rear brake light switch).   The -569 switch must not be overtightened, maximum is 5 Nm (3.6 ftlbs).  Use a drop of blue Loctite on the flange.   When installing a -569 on a K75C with drum brake, cap 35-21-1-244-520 must be pressed onto the head of the screw that activates the switch.

SI 61 017 88 (2305) came out in April of 1988 and was the first bulletin explaining about the pin problem and to file the hand brake lever and to install the -520 cap on the hex head stop bolt for the foot brake lever, and to set the air gap between cap and switch pin to ~3.5 mm.

Next in the chain of SI's was SI 61 019 89 (2342).   This is the big one, that was a Federal Recall.   NOTE that this was for the R bikes!   Rather extensive, with sketches and lots of details:

Details:
The mechanical cable has a small plastic pin...that actuates the switch.  The pin gets bent, and causes the switch to fail.   The brake lever is what is bending the pin.   In bulletin 61-017-88 (2305) BMW said that the hand lever was to be removed and one was to file or belt-sand the milled cutout on the hand brake lever until the plastic pin no longer catches the sharp corner.     On the REAR brake light switch, the stop bolt which actuates the switch might contact the plastic pin at an angle...causing the pin to form a ridge or burr.   For this foot lever, a cap, 35-21-1-244-520 was to be installed onto the hex head stop bolt...and the air gap between the cap and switch pin adjusted to approximately 3.5 mm.

The RECALL was FEDERAL, and the NHTSA number was 88V-192 (the SI announcing this was dated April 1989, and was number 61 019 89 (2342) in the above paragraph's sequence.   1985 through 1988, and SOME 1989 bikes were affected.   Note that the 'recall' in the SI was for the R bikes.
The following vehicles were in the Recall:
R65 serial 6388193-6388255
R65 serial 6128001-6128516
R65LS serial 6371705-6371713
R80G/S serial 6363060-6363352
R80 serial 6480001-6481120
R80RT serial 6490001-6491452
R100GS serial 6152004-6153373
R100RS serial 6247001-6247599
R100RT serial 6292601-6293397

K bikes: 
  All up to the date of the bulletins.   Brake light switch 61-31-1-459-519 was replaced by 61-31-1-459-588.   This switch can be used instead of the plunger-type on all K models that utilize the SOLID MOUNT type of foot rest plate....which has an additional casting rib and mounting hole.   Bulletin 61 014 87 (2263) has sketches and description, and adjustment information.  ALSO in this bulletin is the information on the 61-31-1-459-569 FRONT brake light switch.....clutch safety switch...and choke light switch.    Information on installing the switch (maximum torque is 5 Nm) and use of a drop of Loctite 242 BLUE, is in the Bulletin.  A note in the bulletin states that this -569 switch when used on a K75C (drum brake model)...must have the cap (35-21-1-244-520) pressed onto the head of the screw which activates the switch.

I do not have the Federal Recall Campaign information handy at the moment, for the K bikes...if I find it, I will post the information here.
 


Re:  Stiff throttles.....K bikes....1985 ONLY:

There is a Federal Recall Campaign for this problem.   The NHTSA number is 85V-011, the BMW SI bulletin is  61 010 85 (2143).   This applies to ONLY the following motorcycles:
K100        serial 0030001-0030828
K100RS   serial 0040001-0041020
K100RT   serial 0050001-0050952

The handlebars are rubber mounted, and therefore are electrically insulated.   The brake switch might try to get its 'ground' via the throttle cable, causing, eventually, the throttle cable to be stiff.   The fix was to add a ground wire, per the sketch in the bulletin.  There are even BMW part numbers for the wire, etc.
 


Airheads:

The bulletins had a new REAR switch AND FRONT switch; and a modification was to be done to the front brake lever; and a cap added to the rear brake lever actuating bolt head.....Excepting, I think, the R80GS REAR, for which it did not apply exactly the same way....see later here.  The bulletins have a lot to them, but basically, for our Airheads, the front brake lever itself was not contacting the switch actuating pin properly, the pins bent, and failed.  The switch was updated, and you, or the dealer, was to also modify the front brake lever.  Remove the front brake lever, a very easy job, and file slightly the lever in a certain place so it did not 'catch' the brake switch pin.

For the REAR brake lever, the bolt that actuates the rear switch was not contacting the actuating part of the switch properly, and could cause a broken switch, and BMW supplied a sort of a cap to fit over the bolt head.


How to tell if your bike was fixed?
Inspect the actuating pin of the front and rear brake light switches.  WHITE pins are the bad ones. Black or dark Gray are OK.   NOTE that SOME R80G/S bikes used a different front switch....and if the switch wires can be UNPLUGGED, then it is NOT one of the bad recalled ones.    However, all should be inspected for condition of the pins, lever, etc. To see the REAR switch pin, use a small mirror and press the foot pedal, to then see the pin color.

In any case, the small ridge on the front lever is to be sanded or filed off.

The R80G/S and R100GS do not use the rear bolt cap that is mentioned to be installed on other models.


It is not easy to describe, without a drawing, what is modified on the front brake lever....but, if the lever is removed, you will see the area around the pivot has some...well, notches/cutouts.    There may be a very small very tiny notch on the outer curve, and it is the one to be smoothed.   If you put the lever into place without the pin-bolt holding it, you will rather easily see what portion contacts the switch pin, and why, if you have a lever needing modification, it should be done.

I DO have the various bulletins, and the model and serial numbers of all the USA shipped (ONLY) bikes that were affected....but you can see from inspection if you have a bike that needs the fix.  


Rev:
Initial release:  09/17/2004
01/15/2008:  moved position on technical index page
01/14/2009:  changed article number
03/25/2010:  checked, and slight updates
06/04/2010:  checked, minor update information to make the K bike situation a bit clearer; add stiff throttle
                    information on the K bikes.
 May/2011 :  During updating of this article I still did not find my K bike bulletin on the BRAKE SWITCHES
                    matter (not meaning the stiff throttle SI).....I believe there was a Federal recall, just can't find
                    that bulletin.  However, the details in this article you are reading should be adequate.

 

Copyright, 2012, R. Fleischer


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