My lever is too stiff

[Nipedley]

Oo er

My CBR's front brake lever is bloody stiff, I haven't used it much over winter so not sure if this has contributed.

It's not smooth, it's like it 'clicks' through the travel, the first click from resting is most of my regular braking exertion and does very little braking. The next click requires a lot of force, and brakes very hard. Once it grabbed so tight it actually locked the front wheel, all with barely any lever travel.

The brakes aren't binding at all, both calipers were fully rebuilt last year and regularly cleaned, (last had fresh brake fluid maybe July/Aug last year?) it's a dual disc and running EBC HH pads on both sides (non-sintered EBC did bugger all)

I'm gonna pull the lever(s) and clean and put some lithium grease on the pivots, but wondered if you guys might have any other ideas

Cheers!
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CBR600 (1988) | GS500 (1989)

[Fisty]

Lube is the answer.
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Quietly and consistently taking the piss.
TL1000R | Hayabusa | ZXR400 | TL1000S | Bandit 400 V
Fatter and faster than Fret

[Nemo]

[bikenut]

as above and how is the f/brake master cylinder piston "gaiter or dust boot"??

is it split/has it split??

see cmnsl for exploded views which may help.

sorrty thants cmsnl!
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nuts about bikes

[Nipedley]

I should have mentioned, I rebuilt the M/C last year too. The previous owner was a spaz and bodged a half seized M/C with springs to push and load the lever so that you couldn't tell it was half seized, horrific picture attached. It actually caused the front brake to seize on and crash which has left me with some nerve damage in my left hand (worst bodge)

Sounds like the grease should do the job, if not I'll post back. It's likely never been lubed since it was put on new. Cheers!
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CBR600 (1988) | GS500 (1989)

[bikenut]

you do know where the outer seal goes and which way, that's the ring tapered seal not the tower type dust seal.........

and the hydraulic seal went in the correct way.....

see cmsnl for exploded views.......

the tiny hole in the master cylinder floor ( the re couperating port ) near the high pressure end of the m/cylinder was clear I presume......

you know of the red rubber grease of hydraulic assemblies?

if piston sticky, use some brake fluid injected past the outer dust seal to lube and flush ( a blunt needle inserted in the gap made when the outer dust seals is gently peeled back from the piston....), then inject some red rubber grease via the same method.....else new dust seal and m/cyl kit and full strip, unless you are able to get the dust seal off without buggering it......

if you push the caliper pistons home with a m/cyl res cap off, you will see the fluid displaced "jet" out of the tiny recouperating port, have a rag handy......
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nuts about bikes

[Nipedley]

Hey there,

Yeah it just occured to me to take a pic at the time, I hadn't finished putting it back together at that point (getting that seal down over was quite the pain) I used red rubber grease during it as I'd used that for rebuilding the calipers as well. I did check the port at the bottom of the M/C and that was all good

The bike was fine after the M/C rebuild (would have been January 2014? Put about 4000 miles on since then), it just seems to be bad now after the winter, so fingers crossed it's just the lever needing a good clean and lube (it is a previously badly neglected 27 year old bike) - if not then I'll drop the fluid and have another look at the M/C. I did check when I first noticed the issue the condition of the M/C dust seal and that's all fine still
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CBR600 (1988) | GS500 (1989)

[kramdra]

Sounds like you also bodged it or have got dirt in the system. Do not ride it as is, any doubt you should strip it, check all the parts and reassemble.

remove lever and push directly on piston. How does it feel? I doubt problem is the lever.

Seals can be reused if there is no damage - be sure to inspect them closely and use matchsticks rather than metal tools to remove them to prevent damage if you intend to do this.