Brakes

[aquamantx]

Ok so im sure this has been asked before. How do you clean the grove in the brake caliper used for the piston seal? i have tried the standard stuff, brake cleaner tooth brush, dremel with nylon brush, ect.. it is fairly smooth but I still dont see the nice aluminum shine. Dont want to get too aggressive and damage the seat. Open for suggestions.

[TopCatGr58]

I've used a small tipped flat screwdriver! Remember, it's the O-ring that makes the seal against the piston. SO...you can use a metal wire brush on a dremmel and lightly go after it to remove the corrosion down in the groove.

T.C.

[MindWebs]

3m

green scotchbrite works well.

take a piece of 1/4" steel or SS tubing and cut a grove in down the center of it with a cutoff disk

then cut a strip of scotchbrite to slide into the slot you just cut, make sure to cut it longer then your slot this way it prevents gouging if you bump the end of the tube into your work piece.

load it into a drill and go to town cleaning.
reverse to drill to use all sides of the pad.

scotchbrite removes rust but minimal metal so it is fairly safe to use in many applications.

good luck

[HalfCentury]

I have rebuilt 4 of these calipers. The groove never comes back to smooth original condition. This does not seem to affect the ability to hold a seal. I use a Dremel circular wire brush to remove the crud that accumulates there.

The piston is a different story. That should be smooth where it contacts the seal.

This is just my experience.

[CatatonicBug]

I always just use one of those metal toothbrushes. It never gets shiny, but the seal is fine.

[aquamantx]

will be rolling down to home depot/lowes tonight to pick up supplies for the dremel. Seals showed up today from powerhouse.

[Diskman01]

Seconding the green scotchbrite and small screwdriver. Been cleaning them that way for years. No leakage with new seals.

Now I need to locate some brake pistons for a 78 E... Mine are pitted and if I replace the pads the pits leak. LOL..

[Prisoner6]

... Now I need to locate some brake pistons for a 78 E... Mine are pitted and if I replace the pads the pits leak. LOL..

Check these out:

Yamaha XS Brake Caliper Piston

Stainless steel ... no more pitting or rusting!

[CatatonicBug]

Thought of this thread last night. I discovered that my front left caliper piston won't slide past the seal. I press the brake pedal, and it wiggles in there, so I know it's not binding, but the seal has a death grip on the piston. Of course, with the linked brakes, the amount of pressure sent to the front caliper is limited, so I can't use the MC to keep increasing the pressure.

Even my giant channel locks couldn't break it loose last night. Gonna try a vise tonight, and see if I can apply enough pressure to overcome the seal.

At least I got the rear MC cleaned out in the process, and flushed the old, brownish brake fluid out of the system.

[aquamantx]

Don't go with the channel locks. Remove the caliper.plug the banjo bolt hole. Use you grease gun on the bleEder screw. The grease will pop it out slick as a whistle. use brake cleaner to clean up the grease. Got this handy tip from the forum. Also you ca loosen the death grip of the grease gun by loosening the fitting on the end. It relaxes the pressure on the spring clips.

[HalfCentury]

Thought of this thread last night. I discovered that my front left caliper piston won't slide past the seal. I press the brake pedal, and it wiggles in there, so I know it's not binding, but the seal has a death grip on the piston. Of course, with the linked brakes, the amount of pressure sent to the front caliper is limited, so I can't use the MC to keep increasing the pressure.

Even my giant channel locks couldn't break it loose last night. Gonna try a vise tonight, and see if I can apply enough pressure to overcome the seal.

At least I got the rear MC cleaned out in the process, and flushed the old, brownish brake fluid out of the system.

What you describe is what I would call SEIZED. Both of my XJ1100 front calipers were seized last year. I used a grease gun. The Zerk fitting will snap on to a standard bleeder fitting.

Make sure that the bleeder is backed out enough to allow the grease to go into the caliper. If you don't, the grease gun hose will explode. Ask me how I know.

Once you start pumping grease into the seized caliper, the piston will come out slowly.

Grease is cheap and can be cleaned up. Its a very safe way to remove a piston from a seized caliper. Some people use compressed air. That can be dangerous.

[MindWebs]

what?? compressed air dangerous??

you don't like exploding parts?

it's those little things that keep life exciting.

jokes aside, i have a MC off a parts bike i use for pressurizing the calipers and popping the pistons out.

but it sounds like the grease is a great option as well.

[CatatonicBug]

I got mine squeezed in the bench vise, then used the front MC to pressurize the piston out. I know people like the grease solution, but I REALLY hate the idea of cleaning up all that grease... Besides, I don't think my gun will create enough pressure. It leaks like crazy, and barely puts out enough grease on each pump to do anything. There are times I pump 10 times and get nothing... Anyway, I'll save the grease idea for when nothing else will work.

Actually, as it turned out, this whole thing may have been a mistake. I just had my exhaust off, and the problem started immediately after re-installing. As it turns out, the right exhaust was too far out from center, and the brake pedal was getting stopped by it. I adjusted the exhaust positioning, and got the pedal travel back... I now have clean brake fluid in all my calipers though, and I can stop too!

[aquamantx]

Good to hear you can stop. The grease was an easy clean out for me. I did replace the bleeder screw. Not because of grease just because it came in the seal kit.

[bikerphil]

BTW if you fill the caliper with brake fluid before using the grease gun, there will be very little grease to clean up.