Sticky Brake Lever...

[azcycle]

Still no issues with the "new" used transmission and new clutch! Loving the gorgeous riding weather here in Tucson (82 degrees F today)!

I did notice yesterday that the front brake lever seems to be slow to return. It's not enough to cause any dragging and the brake still feels fine... stops well. But after I pull the brake lever and release, the lever seems just ... slow ... to return. I did drain the system of really, really nasty fluid when I installed new stainless braided lines. Flushed it well... lever feel seems okay but I don't have much experience with what is "normal" feel for this bike.  When replacing the lines, I did NOT touch the calipers themselves. Could this be a symptom of a caliper piston issue?

Anyone ever experience this?

[Bob_Roller]

I would remove the cover on the brake fluid reservoir, there is a very small hole at the bottom of the reservoir, maybe eighth inch or so from the supply hole for the master cylinder .

If this hole gets plugged, it can cause problems with the brakes .

You can use a fine wire to clear it out, with the hole clear, when you release the brake lever, you will get a 'jet' of fluid from this hole, so be prepared, cover all painted surfaces in the area .

[azcycle]

Sorry for being so dense but do you mean to drain and remove the brake line from the reservoir... or can I leave it filled? The old line WAS obviously disintegrating and I had a hard time getting all of the rubber-speckled sludge out of the reservoir. Could easily have missed a small piece that lodged in the pinhole you're referring to.

[Bob_Roller]

No, just remove the three screws that hold the cover on the reservoir  .

Look down in there where the fluid meets the master cylinder about a half inch diameter hole at the bottom of the plastic reservoir and you'll see the two holes, hopefully you'll see them !!!!!

[azcycle]

I wasn't very clear (sorry!) but in order to clear the hole with a wire, do I need to remove the brake line and/or drain the reservoir?

[Bob_Roller]

No, you do it from the reservoir, just take the top off .

It is clogged and you see some debris in the reservoir, might be a good idea to remove the fluid form the reservoir .

[tvrla]

If that doesn't do it, the next thing to check is the brake lever pivot. It's a little screw near the lever on top, with a nut below. Remove the nut and push the screw out the top. The lever can then be removed. Be careful - there's a special wave washer that fits the top of the lever around that screw - it helps take up any slack so the lever doesn't rattle around in there. Don't lose it - it's a special size. The grease could be old and sticky and needs renewing.

[bruce_launceston]

I'm 99% sure that you will need to remove the fluid AND the reservoir from the master cylinder to properly access the brake fluid return hole.
It is tiny, about 0.35mm diameter and can get very gummed up and take a lot of effort to clear.
The major symptom of a blocked fluid return hole is that the calipers won't release, eventually locking the brake on. It happened to me and I had to crack the bleed screw open to release the pressure so that I could ride it home.

You wont have to remove the brake line and shouldn't need to re-bleed the system unless you want to flush out any crud that you disturb. If you haven't had the reservoir off there may be some nasty stuff under it.

To remove the reservoir you first have to remove the screw underneath.

[tvrla]

I think a complete braks system flush is in order for the simple reason calipers hold a fair amount of fluid that doesn't ever get drained unless opened up. The debris my lie there undisturbed causing no problems, but then again, who knows? So keep that in mind.

[Lucky_Lou]

I wasn't very clear (sorry!) but in order to clear the hole with a wire, do I need to remove the brake line and/or drain the reservoir?

You could "Bleed" the level down  as you would normally bleed the brakes to almost expose the bottom of the reservoir the vent hole is very small but you can see it and it should eject a small amount of fluid as the brake lever is pulled.I used a piece of stiff wire snipped off a wire brush held with some long nose pliers when i had this problem.
Lou

[tvrla]

If the brake fluid is so dark you can't see the hole, best to drain it off anyway.

[Red_Hen]

READ YOUR THREAD:
I did notice yesterday that the front brake lever seems to be slow to return. It's not enough to cause any dragging and the brake still feels fine... stops well. But after I pull the brake lever and release, the lever seems just ... slow ... to return. I did drain the system of really, really nasty fluid when I installed new stainless braided lines.

Since fluid was so contaminated, if it were my bike, I'd do the following for good measure:

• Remove calipers, disassemble & inspect - if contaminated, I'd buy a rebuild kit from Motobins and rebuild - a very easy thing to do.  
• Purchase a rebuild kit for your front brake master cylinder - you should see the size stamped on the master cylinder where the handle goes.  


Nothing more important than good brakes and tires!

[/list]

[azcycle]

Sorry for the late reply, and thanks for all the advice. Current fluid is nice and clear, and I did remove the reservoir completely originally.  But I'm thinking that a rebuild of the calipers is in order, since I didn't do it when I installed the new lines and bled/flushed the system.