rear brake light switch - '82 R65

[curtb]

brake light with the rear brake was inop so I traced it to a faulty switch. I bought a new one but the "throw" of the switch isn't long enough to open the circuit. The new switch bench tests fine.

The switch has a rod that extends through the back of the pedal stop plate. When the brake is released there is an adjustable stop bolt/nut that hits the stop plate and pushes the rod on the switch to open the circuit. The problem is, with the stop bolt fully seated against the stop plate and rod pushed to its full extent, it doesn't open the circuit. I need another 1/16 or 1/8 of inch of travel.

Anyone encountered and fixed? Is there an adjustment that I'm missing?

 

[20774]

Is this for the '82 R65? Do things look like this?

https://www.realoem.com/bmw/enUS/showparts?id=0364-USA-01-1982-248-BMW-R65&diagId=34_0599

 

[curtb]

Is this for the '82 R65? Do things look like this?

https://www.realoem.com/bmw/enUS/showparts?id=0364-USA-01-1982-248-BMW-R65&diagId=34_0599

Yes, and yes. Forgot to put it in the subject, sorry. #26 is oriented a little differently on my bike. There are two screws (#28 in diagram) that are vertical rather than horizontal as shown.

#7 pushes against the rod on #26. But it doesn't push it far enough to open the circuit.

 

[20774]

I'll change the title! Just wanted to make sure you got the right part. Note that the pictures are not necessarily a true installation guide, but gives some ideas. This part is used across a wide range of bikes...you can see that if you click on the part number on the RealOEM link.

Would it be possible to fit a longer bolt? The picture indicates it is M6x20.

 

[curtb]

Would it be possible to fit a longer bolt? The picture indicates it is M6x20.

That is where I started but that bolt is what adjusts the stop of the pedal and it bumps up against a stop plate. There is a hole in the plate through which the rod of the switch is activated. So, regardless of the length of the bolt, it isn't going to push further than the plate.

If I could slide the entire switch forward, that might help, but the mounting screws go into tapped holes on the frame...no adjustment that I can see.

I need a longer rod...not the first time I've heard that, LOL

 

[20774]

Thanks. Not near my bike so can't see my setup. If that bolt is only for adjusting the stop location of the pedal, what part of the pedal comes close to hitting the button on the switch? Do you have a picture of what you are dealing with?

 

[20774]

Have you looked at Brook Reams' page on brakes for his rebuild on an R75/5? About half way down on this page...how do things look here versus what you have going on?

https://brook.reams.me/bmw-motorcyc...uild-project/34-bmw-r755-install-rear-brakes/

 

[curtb]

Have you looked at Brook Reams' page on brakes for his rebuild on an R75/5? About half way down on this page...how do things look here versus what you have going on?

https://brook.reams.me/bmw-motorcyc...uild-project/34-bmw-r755-install-rear-brakes/

Just did. Mine looks exactly like that except my rear wheel is on so it is very hard to see and reach.

One point of clarification...I think the bolt that activates the brake light is really the stop for the brake. It doesn't really adjust when the brake light activates because the bolt head always stops on the plate...

In my case, the switch rod wasn't moving enough, regardless of when the bold head made contact.

But, I just engineered (hah!) a solution. I reversed the bolt so that the threaded end will reach the switch rod. Moved the nut to the other side as well to lock it in place. Now, the threaded shaft of the bolt pushes the rod shaft just a bit beyond flush with the plate. it works!

 

[pglaves]

Just did. Mine looks exactly like that except my rear wheel is on so it is very hard to see and reach.

One point of clarification...I think the bolt that activates the brake light is really the stop for the brake. It doesn't really adjust when the brake light activates because the bolt head always stops on the plate...

In my case, the switch rod wasn't moving enough, regardless of when the bold head made contact.

But, I just engineered (hah!) a solution. I reversed the bolt so that the threaded end will reach the switch rod. Moved the nut to the other side as well to lock it in place. Now, the threaded shaft of the bolt pushes the rod shaft just a bit beyond flush with the plate. it works!

If the switch rod needs to be pushed "beyond flush" the switch is defective.