All sorts of things seem to be cropping up lately with my son's bike ('95 GS500E) -- maybe it's the change in the weather or the phase of the moon, who knows?
He got home today saying that the front brake lever was grabbing, occasionally scooting him up toward the tank. I looked at it this evening, and noticed a couple of things:
1. There's a good bit of vertical play in the lever. The knob end of the lever moves about an inch from top of the play range to the bottom.
2. When the lever's pulled in to brake, it pulls smoothly at first, then makes a creaking sound, hanging then pulling in by real small amounts at a time. Both the hinges on the lever (the main one and the one for adjusting the reach) are as tight as they can be, and I put some oil on the main hinge, but that didn't seem to make a difference.
If the lever is forced to the top or bottom of the vertical play, it pulls smoothly the whole way, but does the creaking thing in the middle of the range. It seems like something in the hinge may be worn. Is there a fix for this, or does something need to be replaced?
Thanks.
Why don't you remove the 1 bolt holding it on and check for worn parts?
Squart a little WD40 on it and go ride. That's worked for me for 13 years and 170k GS miles. No big deal.
The pivot bolt should not be done up so tight that it restricts the lever's action. It should be done up tight (but not over tight), then locked with the nylock nut. A little play is okay, most levers I've had whether bikes, moto's or cars had some play in them.
A bit of silicone lube would not go astray, though I prefer PTFE spray lube on areas that are exposed to the elements like a brake lever is. Its a bit more persistent than silicone.
Mine sounds like a cicada.
(http://www.greglasley.net/images/SO/Superb-Green-Cicada-0002.jpg)
My master cylinder is different, but also exhibits the same phenomenon when it needs a little lube on the pivot and the end of the plunger.
After letting it sit overnight to let the oil work its way in, I checked the lever before leaving for work this morning, and there was no change in how it was acting. I'll do as Stevo suggested after I get home this evening and see if there's any obvious wear on the lever, the bracket, and/or the bolt.
Quote from: Paulcet on October 11, 2012, 08:54:28 AM
My master cylinder is different, but also exhibits the same phenomenon when it needs a little lube on the pivot and the end of the plunger.
I've never really messed too much with the front brake -- when you say you lube the end of the plunger, do you mean the part of the lever that pushes on the master cylinder, or a part of the master cylinder itself? Thanks.
Quote from: cbrfxr67 on October 11, 2012, 08:48:07 AM
Mine sounds like a cicada.
Like a 13-year cicada, or more like a 17-year one?
Take the lever off.
Clean off any obvious corrosion or rust on lever, bolt hole and the bolt.
Smear white lithium grease on the moving surfaces and in the bolt hole. Over-do it. You can wipe off the excess later.
Put a dab on the end that presses the master cylinder.
Reassemble. Clean and put thread lock on the locking nut.
Should be OK.
Spraying WD40 may not get down into the bolt hole area.
......at least that has worked for me when I've encountered bikes with squeaky brake levers.
Quote from: salamander on October 11, 2012, 11:45:17 AM
when you say you lube the end of the plunger, do you mean the part of the lever that pushes on the master cylinder, or a part of the master cylinder itself? Thanks.
I mean what adidasguy said.
I just looked at my lever, and up-down play at the end is less than 1/2". I would guess there is significant wear on your lever and/or pivot bolt.
:icon_lol:
(http://1.bp.blogspot.com/_x29Pef-T4FQ/Sl3O-l3fq3I/AAAAAAAANY0/BCBL_Iekm4Q/s400/MN08+tree+frog+238_8685.jpg)
13 or 17 year???
hmmm maybe it's more like a tree frog now that I think about it,....
I took the lever off, and although I didn't notice any unusual worn spots on either the pivot part of the bolt or on the lever bolt hole bushing, the two fit together with some definite wiggle room. I may have wear evenly all around, but I'd bet that's what's giving me the excess up-down play in the lever.
Cleaned the parts and put on some lithium grease like adidasguy suggested, and that seemed to do the trick. May still need to replace the bolt and/or lever in the future, but at least for now the jerky braking is fixed, which I thought was an unacceptable safety issue. My son will be happy to know that he can still ride to school in the morning.
Thanks for all the suggestions.
Quote from: cbrfxr67 on October 11, 2012, 02:20:59 PM
hmmm maybe it's more like a tree frog now that I think about it,....
Green tree frog, or gray tree frog (thought maybe you couldn't find a picture of the gray one, and I really want to be sure we're on the same page)? :D
Quote from: gsJack on October 11, 2012, 01:45:40 PM
:icon_lol:
Whether WD-40 would have gotten down in there or not, I appreciate the advice. I used air tool oil, and it did work all along the length of the bolt -- but, like I said, I may have too much space between the bolt and the lever's bolt hole bushing -- and I'd bet WD-40 would have too.
Up and down play may not be things worn out. It may be the top and bottom got spread apart a little from some prior crash that put pressure on the brake lever. The force spread apart the top and bottom of the lever holder thingy a little. Seen it in all the parts I have.
A little and I mean LITTLE pinch with big pliers can bring them back together a little and reduce the play. As long as the bolt is secure and the lever moves freely, some play will not be a safety issue.
Quote from: salamander on October 10, 2012, 07:19:49 PM
All sorts of things seem to be cropping up lately with my son's bike ('95 GS500E) -- maybe it's the change in the weather or the phase of the moon, who knows?
He got home today saying that the front brake lever was grabbing, occasionally scooting him up toward the tank. I looked at it this evening, and noticed a couple of things:
1. There's a good bit of vertical play in the lever. The knob end of the lever moves about an inch from top of the play range to the bottom.
2. When the lever's pulled in to brake, it pulls smoothly at first, then makes a creaking sound, hanging then pulling in by real small amounts at a time. Both the hinges on the lever (the main one and the one for adjusting the reach) are as tight as they can be, and I put some oil on the main hinge, but that didn't seem to make a difference.
If the lever is forced to the top or bottom of the vertical play, it pulls smoothly the whole way, but does the creaking thing in the middle of the range. It seems like something in the hinge may be worn. Is there a fix for this, or does something need to be replaced?
Thanks.
Mine did the same thing recently, I had a "Nothing, creak, bind, grab" set of brakes.
My bike lives outside 8 months of the year.
I did 2 things to the brakes to work the issue.
1) I pulled the pivot bolt on the lever, cleaned up the mineral buildup, and applied liberal amounts of copper paste on all the pivot and contact points, now the lever moves smoothly again.
2) It was time to bleed the brakes due to old fluid, they're much more responsive to the smoothly moving lever now.
Quote from: adidasguy on October 11, 2012, 05:25:53 PM
Up and down play may not be things worn out. It may be the top and bottom got spread apart a little from some prior crash that put pressure on the brake lever. The force spread apart the top and bottom of the lever holder thingy a little. Seen it in all the parts I have.
A little and I mean LITTLE pinch with big pliers can bring them back together a little and reduce the play. As long as the bolt is secure and the lever moves freely, some play will not be a safety issue.
Funny you should mention that -- it was one of the few ideas I've about this on my own. Sometime in the past, before we got the bike, the right side was on the ground and caused some damage to the reservoir, and so I checked to see if the lever holder was sprung a little. After measuring the front and back of the holder tabs, though, they don't seem to be. The amount of space at the lever pivot is less than a millimeter, but between that and some wiggle at the reach adjustment pivot, it translates into a lot of movement at the lever end.
If I can find one thin enough, I was thinking about putting in a hard plastic washer. If that doesn't work out, though, because the gap is already so small, a pinch with pliers would probably work well. Thanks.
Washer might make things bind up.
A little pinch should work. Be gentle. The lever always wiggles a little. If not, probably too tight.
Pinch on the right most part where the lever comes out as that would be where it is spread apart a little.
definitely the green one :icon_mrgreen:
i just lubed up my brake lever, where it contacts the MC piston, it made it 100x better. single drop of 25w50.
i imagine doing that every 1000k miles wont break the bank, or the time bank.
and most of my vertical play was in the reach linkage, where you set the brake lever distance, not in the actual pivot point.
I think I mentioned earlier that the bike has been down on the right at some point, and with the damage to the reservoir, I can't see how the brake lever couldn't have been involved somehow. I'm starting to wonder if the extra play I'm seeing in the pivot joint might not be from a non-oem lever -- I couldn't tell you whether the current lever is the original or not.
This evening or tomorrow, I'm going to give adidasguys' idea of pinching the holder tabs together a little a try to see if it makes a difference. If it does, great, if not, the amount of play seems unusual, but I'm not too worried about it. The big issue was the grabbing, and the lithium grease seems to have cured that.
its pretty annoying when all of a sudden your front brake grabs on real hard, isnt it? I find it... disturbing.
Disturbing is one way to put it when you suddenly find yourself riding up onto the tank. And ... this is why I don't use ArmorAll on motorcycle seats ;).
:)
I don't think that's the only reason you don't put Armor All on the seat!
I rode with a coworker in his SUV with leather seats on an all-day business trip once. Because he was going to be chauffer in his own vehicle, he decided to have it detailed (got to make an impression on the boss). Sitting most of the day on those Armor All'd seats, my pants soaked up enough to make my commute home on the bike rather exiting!
i bet your seat looked shaZam! hot though.
Quote from: Funderb on October 12, 2012, 02:27:26 PM
i bet your seat looked shaZam! hot though.
Only if he was wearing leather pants. :icon_mrgreen: