Brake light adjustment issue

[camos]

There is something funny happening with the rear brake light. The brake is being applied before the light comes on. The switch adjuster is backed out until the switch is tight against the fuel tank. The pedal height is about right and there is about 1/2 play before the brake grabs. Do I totally not understand how this thing is supposed to work?

 

Have not pulled the passenger board off yet but it's getting dark so that will have to wait for another day.

 

Any suggestions?

[videoarizona]

Do you have the owners manual or the service manual? The procedure for adjusting the pedal free play, pedal throw and brake light all need to be done in sequence or it won;t work. I don't remember the exact sequence but know the info is available here. Look in the Maintenance only section for 1st gens...

david

[camos]

Do you have the owners manual or the service manual? The procedure for adjusting the pedal free play, pedal throw and brake light all need to be done in sequence or it won;t work. I don't remember the exact sequence but know the info is available here. Look in the Maintenance only section for 1st gens...

david

I do have the manual and I did the height adjustment and free play adjustment as per the manual but all it says for adjusting the brake light timing is to hold the switch and turn the adjuster nut until the timing is correct. Not much help there. The only thing I can think of is there is an issue with either the hook or the spring. Unfortunately they can't be seen without removing the passenger board. Another thing to do this coming Sunday. It just never ends.

[videoarizona]

Where is your shaft linkage in relation to the adjusting nuts?

 

The adjusting nuts on my shaft are about halfway to both ends...leaving the link between the shaft and the rod above...almost vertical. The brake pedal rod (#71) and the "boss"(part #77).....page G2 on the parts diagram pdf....

[icebrrg3rd]

Mine was having this issue, in that the light wouldn't go on at all with the pedal. The switch was adjusted all the way but still wouldn't turn on. I saw that the spring part that hooks the pedal to the switch had stretched, I squished it back together and it worked, adjusted the switch so it lit just after the free play portion and the brakes were starting to be applied. Might want to check the spring, even if it isn't stretched out, you could put a kink in the straight part to shorten the overall length of the spring.

 

-Andrew

[Great White]

I was going to suggest the hook/spring assembly is stretched, but it's already been mentioned.

 

That's where I would place my bet if your switch is all the way up on the nut....

[camos]

Where is your shaft linkage in relation to the adjusting nuts?

 

The adjusting nuts on my shaft are about halfway to both ends...leaving the link between the shaft and the rod above...almost vertical. The brake pedal rod (#71) and the "boss"(part #77).....page G2 on the parts diagram pdf....

That is pretty much what mine looks like too.

 

Mine was having this issue, in that the light wouldn't go on at all with the pedal. The switch was adjusted all the way but still wouldn't turn on. I saw that the spring part that hooks the pedal to the switch had stretched, I squished it back together and it worked, adjusted the switch so it lit just after the free play portion and the brakes were starting to be applied. Might want to check the spring, even if it isn't stretched out, you could put a kink in the straight part to shorten the overall length of the spring.

 

-Andrew

I think the spring hook is the most likely cause for my issue. Too bad it can't be seen without taking the passenger board off. Hopefully the board will come off easier than the one on my 90 VR which had one bolt that to be drilled off.

 

So.... rather exciting ride to work this morning. Got 2/3 of the way in, was in the passing lane travelling at about 60 mph when it felt like the bike started to run out of gas.... but had half a tank. Gave it a bit more throttle and headed for the right shoulder. Fortunately no traffic in the immediate vicinity at least. Rear brake finally seized up leaving the front half of the bike in an on-ramp and the rear half in the travel lane. Very fortunate I think, a tractor trailer was the first on the scene and he stopped with his four-ways on which made the rest of the pack either stop or go around. Kudos to professional drivers!!

 

Took a few minutes to back off the free play locknut and I was able to roll the bike off the highway. Only got a couple of "friendly" fingers for that one. :duck:Very lucky, could have been much, much worse.

 

The specs say .5 - .6 inches of free play. Pretty sure there was .5 but now there is 1 inch. Much safer with too much than not enough.

[videoarizona]

Clive, True...but also make sure your rear master cylinder is not to full. Brake fluid expands...and if you are right on the line of being to full, just a little bit of brake drag would heat up the fluid enough to where the .5 inch free play isn't enough.

 

In other words, the brake drag you had might have heated up the fluid, which expanded it's normal amount, but that added to the brake drag even more. Your .5 inch could have been enough free play if the fluid level was lower....

 

Again, thinking out loud here...

[camos]

Clive, True...but also make sure your rear master cylinder is not to full. Brake fluid expands...and if you are right on the line of being to full, just a little bit of brake drag would heat up the fluid enough to where the .5 inch free play isn't enough.

 

In other words, the brake drag you had might have heated up the fluid, which expanded it's normal amount, but that added to the brake drag even more. Your .5 inch could have been enough free play if the fluid level was lower....

 

Again, thinking out loud here...

Good point, I'll check it all out on Sunday.

 

Don't want to go through that Hoo-Haw thing again. Being lucky once is more than I usually get.

[Venturous Randy]

I always carry a 8mm or 5/16 wrench in a handy place, especially if I have been working on the brakes. One thing to remember with linked brakes is that if the rear brake is getting tight that the front brake should be also. The good thing about this is you don't have to get under the bike and bleed the pressure off the rear caliper, you can also do it off the left front caliper.

Just try to have a towel so you don't get fluid on the pads.

Randy

[Great White]

You know, I had a similar issue on my 83 but it was the actual lever pivot where it goes through the frame.

 

It had been sitting long enough that it had rust inside the bore. This caused the lever to not move freely and return to the released position. The return spring just didn't have enough "poop" to overcome the drag. I had to pull the pivot out, clean and lube the bore and reassemble. No brake drag or stop light issues since.

 

Not likely your issue, but worth an check. All you have to do is press the pedal a couple times and verify it returns to the same position each time. I found mine by pulling up on the lever and each time it had some up travel left that would let the wheel roll freely and turn the brake light off. It was very deceptive because there was enough "slop" in the linkage that it looked like free play but the brake was actually still on a tad.

 

Good luck

 

Edited June 27, 2015 by Great White

[camos]

I always carry a 8mm or 5/16 wrench in a handy place, especially if I have been working on the brakes. One thing to remember with linked brakes is that if the rear brake is getting tight that the front brake should be also. The good thing about this is you don't have to get under the bike and bleed the pressure off the rear caliper, you can also do it off the left front caliper.

Just try to have a towel so you don't get fluid on the pads.

Randy

I bled the brakes a week or two earlier and did not experience any problems. It wasn't until the morning after messing with the rear pedal adjustment that this problem appeared. Can't say I noticed any issue with the front brake at the time but to be perfectly honest, I couldn't budge the bike after it happened so there may have been some affect on the front brakes. I always carry the complete Yamaha tool kit with a few extras in the saddlebag so I have all the tools needed to adjust or repair almost everything.

 

That said, your advice is well stated. Bleeding the brakes would have been the second thing I tried. The tool kit does include a hose for bleeding the brakes and getting under the bike to do the rear caliper is not necessary as the hose can be attached to the bleeder valve by reaching in through the gap in front of the right saddlebag.

 

Thanks for chiming in Randy.

[camos]

Not likely your issue, but worth an check. All you have to do is press the pedal a couple times and verify it returns to the same position each time. I found mine by pulling up on the lever and each time it had some up travel left that would let the wheel roll freely and turn the brake light off. It was very deceptive because there was enough "slop" in the linkage that it looked like free play but the brake was actually still on a tad.

Can't say I noticed any issue with the pedal travel at the time. Good point though so tomorrow when I get into it again I'll check that out and give it a bit of a lube.

 

Thanks GW.

[camos]

Today I removed the right muffler and was able to remove the rear brake light spring from the switch. The spring was stretched. Cut off 1/4 inch, bent the end into a circle, hooked it back up and it worked...just like magic.

 

Could not get the switch and adjuster out. Something is not right there. The threaded bracket that is welded to the frame is canted outboard a bit. Is that the way it is supposed to be? Looks to me as though the bracket should be horizontal which would make a little more room between the switch and fuel tank.

 

Anyone familiar with this situation?

[Great White]

My 83 has the bracket at (what looks like) an odd angle.

 

I had to thread the nut off the switch before it would pull out of the bracket.

[camos]

My 83 has the bracket at (what looks like) an odd angle.

 

I had to thread the nut off the switch before it would pull out of the bracket.

Ahh... Looks like mine might be normal then. Will file that little knowledge nugget under "May Need To Know At Some Point".

Still a fountain of information GW.