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Broken front & rear brake light switches;
BMW Airhead and K bike Motorcycles
https://bmwmotorcycletech.info/brakeswitches.htm
37B
© Copyright 2020, R. Fleischer
This article is not about the hydraulic pressure activated brake switches. Those switches, originally 34 31 1 233 959, were replaced with 61 31 1 244 334. 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.
BMW Service Information Bulletins (known as SI's) were issued regarding the front & rear brake light switches, brake lever, etc. The bulletins applied to both Classic K bikes & to Airheads, but not exactly the same way. There were bulletins issued in 1987, updated in 1988 & a formal recall in 1989. Later bulletins were longer, with more details. All R series bikes FROM 1985 model year through 1988, & SOME 1989 Airheads were affected. ALL models of Airheads for those years!
Federal Recall Campaigns SEEM TO 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),......if it applies to your bike, & you have the switch contacting problem...it will be handled totally by your dealer at no cost to you.
SI 61 014 87 (2263) came out in August of 1987 & covered ALL BMW models. It said that rear brake light switch on K models 61 31 1 459 588 & 61 31 1 459 569 front & 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 & 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, is positioned correctly when there is a slight gap between the levering tab & the foot rest plate, & 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, & a choke light switch.
On R bikes, the new 569 switch can be used at both front & rear brake light switches & 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 & was the first bulletin explaining about the pin problem & to file the hand brake lever & to install the -520 cap on the hex head stop bolt for the foot brake lever, & 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 & lots of details:
Details:
The mechanical cable has a small plastic pin ...that actuates the switch. The pin gets bent, & 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 & you were 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...& the air gap between the cap and switch pin adjusted to
approximately 3.5 mm.
UNofficial information from Snowbum: I have seen the offset pin problems on many Airheads, all the way through the end of production in 1995. If you remove the rear wheel, you can probably do some careful bending of the switch bracket, and eliminate that plastic CAP (which eventually wears from the pin). A minor adjustment of switch position may be needed (simple nut/adjustment).
The RECALL was FEDERAL in the USA, & the NHTSA number was 88V-192 ....the SI announcing this was dated April 1989, was number 61 019 89 (2342) in the paragraph's sequence. 1985 through
1988, & 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
Airheads:
The bulletins had a new REAR switch & FRONT switch; a modification was to be done to the front brake lever; & 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, failed. The switch was updated; you, or the dealer, was to also modify the front brake lever. Remove the front brake lever, a very easy job; 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, & could cause a broken switch. 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 & 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 .... & why, if you have a lever needing modification, it should be fixed.
I DO have the various bulletins, & 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.
K bikes:
This applies to 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 & mounting hole. Bulletin 61 014 87 (2263) has sketches & description, & adjustment information. ALSO in this bulletin is the information on the 61 31 1 459 569 FRONT brake light switch.....clutch safety switch.....& 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, if I remember this.
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, & 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 BMW part numbers for the wire, etc.
Rev: © Copyright 2020, R. Fleischer
Initial release: 09/17/2004
01/15/2008: Moved position on technical index page.
01/14/2009: Changed article number.
03/25/2010: Checked; 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.
01/23/2016: Narrow the article, update meta-codes, increase font sizes for better readability, more left justification.
05/17/2016: Final update on metacodes, layout, etc. SLIGHT changes for clarity of information.
12/08/2017: Reduce excessive html. Greatly reduce colors and fonts changes. Clean up, incorporate better layout. Add 10pxl margins.
11/24/2020: Minor cleanup and notes.
Last check/edit: Tuesday, December 15, 2020