Rear Brake Pedal Pivot Bolt Missing Inner Bushing?

F451

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#1
Hey guys, does anyone know if I'm missing an inner bushing or collar on my rear brake pedal assembly? The mounting bolt/pivot bolt does not appear to have an inner bushing or collar which is causing issues with my brake pedal. If I tighten the bolt down enough to eliminate the wiggle, it binds. If I loosen it enough to undo the binding, it wiggles on the mounting bolt too much. It appears that there should be a bushing or collar around the bolt on the inner side of the pedal that the pedal could pivot on, and also would allow you to tighten up the pivot bolt without causing binding.

<edited, removed erroneous info>

I disassembled everything, cleaned and removed the white grease, re-greased with waterproof bearing grease, installed the helper spring, same results. Either binding, or wiggling.

You can see on this pic the gap between the bolt and the inner pivot hole and the bolt is offset to one side and has plenty of room to move side to side.

IMG_2297-M.jpg

Everything cleaned up, lubed and reinstalled.

IMG_2299-M.jpg
 

Philip

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#2
It looks like everything is there.

You didn't mention the stock return spring. Where is it?

In my experience, the stock return spring is the one that is causing all the rubbing and binding. I think it has a wrong shape. Mark911 thinks the hole for it should be drilled somewhere else. Either way, the problem is with that spring.

The bolt that you are talking about should be tightened tight. Try installing it without the spring first to see how it should work.
 

C5tor

Chief Comedic Instigator
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#3
I had much the same issue. Cleaning up the white grease helped a bit. Adding a second spring helped a bit too. But I never got it to move freely. I finally just chucked the whole thing and installed a Left Hand Rear Brake and removed the pedal altogether. Much happier now.
 

F451

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#4
It looks like everything is there.

You didn't mention the stock return spring. Where is it?

In my experience, the stock return spring is the one that is causing all the rubbing and binding. I think it has a wrong shape. Mark911 thinks the hole for it should be drilled somewhere else. Either way, the problem is with that spring.

The bolt that you are talking about should be tightened tight. Try installing it without the spring first to see how it should work.
Thanks I will try and remove the spring but I don't think that is the main issue. The pedal pivoting on the threaded portion of the bolt is a very strange design and seems like it would cause binding and wear on the threads. Its only a matter of time before the threads wear down and then there will be even more play.

I've fiddled with it quite a bit from very tight to very loose, I'm positive everything is installed correctly, just a poor design, I've never seen another brake pedal assembly pivot on a threaded bolt, and also have such a narrow engagement area to pivot on, seems strange.
 

F451

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#5
I had much the same issue. Cleaning up the white grease helped a bit. Adding a second spring helped a bit too. But I never got it to move freely. I finally just chucked the whole thing and installed a Left Hand Rear Brake and removed the pedal altogether. Much happier now.
Sounds exactly like my experience. And yes, I'm in the middle of a LHRB install, but I want to retain the rear brake pedal for now until I see how I like it. Broke a banjo fitting on one of the lines late Friday so have to order up another one tomorrow, damn it, Lol.

I think if I install a collar around the pivot bolt is will help a lot. A shoulder bolt would also be a huge improvement but I'm not sure I have the energy to try to track one down at Fastenal or Tacoma Screw, but I may give that a try.
 

F451

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#7
This is not the design. The steel bushing that is passed into the aluminum arm stays stationary. Push it out and lube it.
Yes that is correct now that I think about it. But isn't it true that the more I tighten the bolt, the more it will push the entire assembly against the spring and the mounting surface? Causing binding? Seems like an inner bushing/spacer would prevent the pedal from being tightened up against the spring and the mount.

And I already pressed out the bushing, cleaned it, greased it, re-installed it. No joy.

I will fiddle with the assembly some more and see what I can learn.

And I edited my above comments to remove the incorrect info about the pedal pivoting directly on the threaded pivot bolt, don't want to confuse anyone there, thanks for the clarification Philip.
 

Rashid510

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#8
Ahh this is a fun thread...

White grease = Lucas oil Lithium grease...we had a few guys get happy with it in production. When I did my LHRB replacement it was also very greasy. (MX)

I just checked the play on my rear brake on my SM, did not have the same behavior. Did you have a spring in the bolt stack up that goes through the Ferrule (the "bushing") (item 11)
Also do you have o-rings (item 7)?
1591551068913.png


1591551258059.png
 

F451

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#9
Ahh this is a fun thread...

White grease = Lucas oil Lithium grease...we had a few guys get happy with it in production. When I did my LHRB replacement it was also very greasy. (MX)

I just checked the play on my rear brake on my SM, did not have the same behavior. Did you have a spring in the bolt stack up that goes through the Ferrule (the "bushing") (item 11)
Also do you have o-rings (item 7)?
View attachment 5452


View attachment 5453
Thank you for the diagram! For some reason I could not find it.

Yes I have the spring (#11) installed just like your pic shows and yes the two o-rings (#7) are there on the insert (#2), which I have already pressed out, cleaned, re-greased, and re-installed.
 

Philip

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#10
But isn't it true that the more I tighten the bolt, the more it will push the entire assembly against the spring and the mounting surface? Causing binding? Seems like an inner bushing/spacer would prevent the pedal from being tightened up against the spring and the mount.
No, this is not true. You need to remove the spring and figure out how to make the pedal move freely while the center bolt is tightened tight. It should move freely, the only friction being the lube in the bushing and the two rubber seals.
 

F451

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Seattle
#11
No, this is not true. You need to remove the spring and figure out how to make the pedal move freely while the center bolt is tightened tight. It should move freely, the only friction being the lube in the bushing and the two rubber seals.
Yes you are correct again, thanks again for the clarification. I took a closer look and the inner bushing protrudes very slightly from the inner pedal side, so the pedal should not interfere with the mount.
 

leeo45

Geezer in denial
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#12
I have had the rear brake levers off and on both of my bikes at least a couple of times. I've never seen this binding issue. The bolt tightens down on the ferrule and the ferrule becomes a rigid pivot for the lever. The ferrule is slightly longer than the collar on the lever so that the lever doesn't bind. The 'slop' between the bolt outer diameter and the ferrule inner diameter is not an issue once the bolt is torqued. The spring then fits snugly but is not in a bind on the collar on the back side of the lever. As Phillip said above, if you install the parts without the spring the lever should move freely with the bolt tight.

I have installed a helper spring on the banjo bolt, but that is primarily to give my size 13 feet in MX boots some chance of knowing whether I've applied pressure on the lever. I have a LHRB on my MXR and will be adding the same to my EXR shortly.
 

F451

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Seattle
#13
After disassembling and reassembling it a few more times and not having any luck with getting the pedal to snap back into position the way I am used to seeing bikes do, I removed the inner rubber o-ring from the bushing, reinstalled every thing and its much better, works pretty much like a normal brake pedal now, maybe slightly slower to snap back.

I think the one o-ring on the inner side will be fine for now. I put as much grease on the bushing as it would take, that should help keep any moisture and crude out for the time being. The outboard side looks like a very close fit for everything so I think it will be fine for now.

After a couple of rides I'll pull it apart and see if I can spot any dirt in there or signs of wear on the pedal bore or bushing.

I should also mention, its really easy to get the a portion of the last coil of the spring trapped between the pedal and the mount causing friction of course, so make sure to keep an eye on that when assembling.

Thanks for the input everyone.
 

Philip

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#14
I should also mention, its really easy to get the a portion of the last coil of the spring trapped between the pedal and the mount causing friction of course, so make sure to keep an eye on that when assembling.
That's exactly what I wanted to say. You just said it way better than I could.

Congrats!
 

F451

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Seattle
#15
Pedal assembly reinstalled, adjusted the pedal height and brake engagement, bled/flushed the fluid. Working like the bees knees now.

Bushing o-ring in a baggie, labeled and put away. Skid plate back on, all buttoned up. Stoked!

Thanks again for everyone's help (and patience) on this one. -Eddie

Ps: now on to my 10 years (10 years!) stalled 928 project. Goal is to get it started, do some minor fiddling with it. Get the spares, manuals, paperwork, etc, sorted. Sell it in the next 3 weeks. AND then buy a used KTM 350 XCF-W. I can't wait. Haven't had an ICE dirt bike for too long now. Yeah me, Lol.
 

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