The
story behind the broken brake light switches (front and rear)
ALSO: stiff throttles, on ONLY 1985 K bikes
brakeswitches.htm-37B
©
Some BMW Service Information Bulletins were issued regarding the front and rear brake light switches, brake lever, etc. The bulletins applied to K bikes and 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 2263; 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
The mechanical
cable has a small plastic pin...that actuates the switch.
That pin gets bent, and that 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...when 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:
K 100 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.
Talking about our 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.
SO....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.
btw...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. At the point I updated this article in June 2010, I still did not find my K bike bulletin on this matter.
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