Topic: Uneven wear of brake pads

[Vertigo]

Hi again,
I'm checking the front brake on my cb500. The brake pad in caliper A is much more worn than the B. I am guessing that the caliper mount (don't know the name so see picture) isn't moving properly and doesn't press the pad B on the disk.
I suppose this part rotates around a vertical axis. Would it possible that part is stuck and no longer rotates. You can see on the picture that the adjusting screw is also missing.
In a normal operating brake, would I be able to move the caliper by hand? Because here the travel of the calipers (horizontaly) when I try to move it is almost none.

[05c50]

I guess that the easiest way to reply is to say that all movable parts on a disc brake assembly need to move freely to operate properly and not cause uneven wear. The piston must move freely to push the inner pad towards the rotor. As it does that, the caliper must slide freely to allow the pressure to be applied to the outer pad. The  missing screw, nut, and spring need to be there and adjusted properly so as to allow for proper clearance to the rotor.

.....Paul

[flybox1]

the adjustment screw is necessary to provide separation from the rotor of the (fixed) inside pad.
without it there, the constant contact of the pads will wear them and your rotor quickly.
If I grabbed both of my front brake units, i would find them immovable, too.

[Stev-o]

I have a 550 with a good operating brake system and cannot move the caliper.
Have you ever adjusted the caliper arm? The stationary pad should be adjusted to .006 in. clearance

[Bodi]

The arm can't lock up enough to prevent the caliper from squeezing the disk. The hydraulic force available would bend or snap it if it tried. You would also have approximately zero braking if your caliper could only press on one side of the disc. If the arm pivot is seized one pad will tend to not lose contact after braking and wear faster (with some drag), if it's free without the adjuster I don't really know what would happen.
If you remove the caliper bolts the two parts come off the arm and you can check how stiff the pivot is. It is simple to disassemble the pivot for cleaning and lubrication. You should get and use the adjuster parts.

[Vertigo]

Thanks,
I'm just trying to figure out what is normal operating condition. I have ordered the adjusting assembly, hopefully this will help solve the problem.

[Vertigo]

Hi,

I removed the whole assembly and the bracket on which the pads are mounted was indeed completely stucjk. So I cleaned it and put it back with the adjusting screw.
Trouble begins when I changed the brake pads: impossible to get the wheel turning freely and when Inapply brakes, the pads get stuck on the disk. I had. To put the old pads back on. Turning the adjusting dcrew doesn't change much. Even with the old pads, I can't get the wheel to turn freely. I don't know what I did wrong.
Does anyone have an idea?
Thanks,

[Stev-o]

At this point, I would rebuild the caliper.  Completely disassasle and remove the piston and seal.  Clean clean clean the inside especially the groove. 
Order a new seal.  May not be a bad idea to put a coat of caliper paint on it since it's all broken down.

[Dunk]

In a normal operating brake, would I be able to move the caliper by hand? Because here the travel of the calipers (horizontaly) when I try to move it is almost none.

Mine moves. Can't really see it but can feel a tiny amount of free play in the caliper between pads and disc. You need to adjuster screw and spring or it will drag slightly and wear one side faster. Everything should be clean, greased, and move freely. If your piston, seal, or caliper groove have imperfections or are not clean you'll have issues and the piston will not retract those few thousandths and you'll get drag and odd wear.