Total Motorcycle Community Forums

There is square oring that goes around the piston. Carefully remove it then take a single edged razor blade GENTLY scrape all four sides clean. You need to clean the recessed area the oring sits in. A brass brush, or what I use. I smash the end of an aluminum welding rod flat. Put a bend in it and scrape it with aluminum on aluminum. Emery cloth will work on the groove and other stuff as long as you don't scratch it. Piston should be free of Pitt's. If you have Pitt's and need a better used one or new one okay, but JB weld might work in the pits if you sand it smooth.

Well, cleaned up the caliper assemblies and the brakes still drag. After the brake is applied and then released the pistons will compress the pads as it is supposed to but then will only return a fraction of the distance that it extended. I'm pretty confused right now the pads are brand new, could they just be too big? The master cylinder has also been rebuilt. Help please, thanks!

So now that the brakes are re-done, how much do the brakes drag? The pads should only move a short distance back after application and can still drag a tiny bit, especially when the wheel is being turned by hand. So your brakes could be working right...

Do they (the calipers) heat-up when riding and not useing the brakes? Is the bike difficult to push around the driveway? These would be bad signs, indicating brake drag.

I haven't ridden it yet, but I can turn the wheel by hand but much more laborsome then without the brakes on the bike at all. If I open the bleed screw and let a little fluid out the brakes will return all the way and the wheel will spin freely.

there is a tiny hole in the master cylinder to let the fluid return after applying the brakes.some of them have a small cover over them.see if it is stopped up.if it is take a piece of wire and unstop it.dont pull the lever hard then let it off with the little cover off if it has one --if it aint stopped up fluid will spray everywhere when it returns.

Saddle up and take that hoss around the block a couple of times. Use the brakes carefully to be sure they are safe, then work them a bit harder. Then re-check everything. See what develops.

I know it has been a while, but I'm definetley not squirting any fluid out the top when I return the lever. BTW it is quite difficult to push around when it is dragging like this. So you are telling me there is something up with the master cylinder?

9000white wrote:there is a tiny hole in the master cylinder to let the fluid return after applying the brakes.some of them have a small cover over them.see if it is stopped up.if it is take a piece of wire and unstop it.dont pull the lever hard then let it off with the little cover off if it has one --if it aint stopped up fluid will spray everywhere when it returns.

take the master cyl.off clean it out and find that little hole and take a piece of wire and a air hose and clean it out.

Had the same problem when I first got my bike. Took pistons out cleaned up pistons wall, cylinder walls(used 3000 grit wet dry emery cloth) cleaned up o ring grooves(real important), and replaced the o rings(bit the bullet and glad I did)( also real important as the o rings help pull the piston back into the cylinder) Stiff old o rings equal pistons not fully returning.Brake pads should be lightly dragging . Goood luck!