Front Brake caliper

I'm having this issue where the front brake caliper builds up pressure and seems that it dont release all the way.

I have blead them several times no air in lines. Cleaned the caliper piston twice. Put all new DOT3 break fluid in.

It's good for about 3hrs then it starts dragging the pads again and they strart squeaking. If its like a car I know there gonna drag a little.I have new pads on the way. I'm trying to solve the problem though before I put the new pads on.

Could this just be bad break pads? Thanks

 

could it be the dreaded relief passage?...

If you look inside the MC, you will see what looks like an unfinished hole next to the big intake port. There's a tiny passage in the middle of it... That's the relief port. When it's unobstructed, you should have a fountain of brake fluid come out of it when you squeeze the brake handle. If you don't, then that's most likely your problem. Be careful not to make that tiny passage any larger when you're cleaning it out... You will need some very thin gauge wire -- thinner than a sewing needle.

 

Thanks for your reply. Is there anything that can be damaged in that hole when sticking something in there?

 

Only the paint job on the tank, if you don't protect it, when you squeeze the lever with the cover off you can have a vesuvius. 8O

 

Well that must be it because I squeezed on the handle as hard as I could and no fluid came shooting out. So I'll try to find something to fit down in there.

I just want to get this right, When its unpluged and I sqeeze the handle it should be very noticable when it comes out the that hole?

 

It's when you release the lever you get fluid back into the MC.

 

I got a piece of wire in there to try and unplug it and It didnt work. I got a few bubble to come through. I cleaned out everything I could to try an unplug it. I clean out where the break hose connects to the MC. Anything I can put in there to maybe desolve the crap that in there?

 

Your wire was probably too big or too stiff. I used ONE bristle plucked from a nylon brush held in a hemostat and had to work it back and forth quite a bit. Once you get it right, you can get about a 4" or higher "squirt" if you grab the lever so be careful.

 

I used one from a metal brush for a drill. Don't know the metal, but it was pretty flexible and worked well...Thar she blows!

 

Ok thx again guys for the info. I will try that again tomorrow if it's not raining and I'll fill you in on my results.

 

I got a piece of wire down the hole abot an inch and it seems to be bottoming out. Is an inch long enough? I still dont have that stream of brake fluid. Nothing has changed, any other ideas?

 

http://www.bikebandit.com/houseofmotorc ... 82/o/m8214 :lol: :lol: :lol:

 

Are you sure your in the right hole? My recolection is there are two down there and you gotta get them both clean. Are you doint this with the piston in? If yes, try taking the MC apart and doing it...

 

Well I went out to pull the piston and I was backing off the screw that compresses the cylinder and it started working. The previous owner must of turn the screw all the way in. Not sure if was supposed to be that way, but I backed it off about 1/4 to 1/2 and it went to working. So If you guys have any input on where that screw is supposed to be set fill me in. My worry is the screw will vibrate out from being loose. Thanks again guys for your info!!!

 

So you're saying the piston was pushed in a bit even when the handle was released?

And here we are assuming things :-D

Get you a lock nut for that screw.. Set it so it just barely touches the plunger when the handle is out and tighten the lock nut.

 

Correct. I didn't know about that screw, Felt like an idiot!! I'm glad I found it when I did because I was about an hour away from odering $150 worth of parts from Len. Thanks again guys!!

 

great they work, but how good are they. Are they 26 years old without a change in the whole time? How much do you trust your 26 year old brakes? Might be worth the 150 for a rebuild of calipers, MC and lines...

There can be some nasty stuff in there just waiting to fail at an in opportune time. I saw it with my own eyes and had rears fail.

 

They work great and I never had a problem with them stooping me on a dime. They just never seemed to realease all the way. I have went through the caliper and the master cylinder cleaned it all out and everything seems to be in order and no leaks.

It's just been a long time since I've been on a bike or even worked on a bike so I wasnt aware of the MC piston haveing a screw adjustment. This guy I bought it from so far has had the clutch adjustment way off and know this. Thanks again guys for all the replies.

 

As long as you cleaned and replaced fluid, great. Now go check the backs for delamination...