Rebuild Calipers?

[XSLevi]

Any one here ever rebuild a front brake caliper? Clymer manual tells me that special tools and experiance are needed, & just turn it over to a professional. I'm thinking that sucks, I wanna do it myself.

[GARTHXS]

Its actually very easy and parts are not always needed. Pull the caliper unscrew the bleeder and take off The rubber boot. If the piston is not frozen you can grab the lip of the piston with some vice grips and pull it out. Then clean the cylinder and the piston. Also make sure the groove is all clean as well as the square oring. Make sure there are no contaminants and coat the piston with brake fluid and put some in the cylinder reinstall and bleed.

[XSLevi]

very good, thanks.

[kevxs]

i am by no means and expert but i had no trouble rebuilding the calipers myself.
the hardest part is getting the pistons out (until i learned the trick)
i unbolted one of the calipers and squeezed the brake lever to push the piston out. for the second one you can't do that because the pressure in the line will be gone. I used a grease gun hooked up to the bleeder screw (with a bolt plugging the other hole) to push that piston out.

after that its just a matter of cleaning it all up, especially under the rubber seal where the piston sits, lots of brown gunk there.

the rear is a little more work cause you have to take a axle off but I did all 3 and it was well within my limited skills

good luck!

[XSLevi]

That piston trick will be invaluable Kev. I gave up on it after trying to pry them out w/ a flat head. Thanks.

[kevxs]

haha i hear that, after prying for 30mins with every tool in the box and not moving it 1mm, gets a little frustrating. mine weren't even in that bad of shape but there was no way i was going to pull them out with anything

[kevxs]

of course i can't take credit for the trick, one of the xs gods on this site supplied that little tidbit

[crazy steve]

I'll add a couple of things.... if you've got one caliper giving trouble, bite the bullet and go though all of them (and the master cylinders if you haven't already). If the others aren't screwing up yet, they probably will. If you find rusted/pitted pistons, you can get new stainless steel replacements here: http://www.hvccycle.com/brake-caliper-pistons.html

And you don't need to pull the rear wheel to get the caliper off; remove the slide/pivot bolt and pull the caliper, leaving the mount in place...

[petejw]

with a set of vice grips,
you can also lightly clamp the rubber hose that the calliper
came off, and remove the 2nd piston by pumping the brake lever,
wont work with ss lines tho.

[Prothec]

I used a grease gun hooked up to the bleeder screw (with a bolt plugging the other hole) to push that piston out.

You could try an air compressor first - make sure you are ready to catch the piston from flying across the room, through.

My front caliper pistons on the XJ were frozen when I was (re)building it and I was able to get one piston out with an air compressor, but the other I had to use a grease gun. The attachment I used had a rubber end that sealed up nice in the hole just holding it there.

The grease gun trick sucks when you need to clean out all that grease...

Edit: We just need small brake fluid cartridges for a grease gun!

[andylawcc]

sorry to revive this old thread, but I used another method with a bicycle pump like this
http://www.harborfreight.com/hand-air-pump-94046.html
plus the small 'needle nose' attachment.

Plug that into the hole where the brake fluid hose connects to; now, even with the small attachment it will not be a perfect fit. Use those teflon sealing tape to create a airtight seal,
http://www.harborfreight.com/1-2-hal...ape-39625.html
and pump away.

It worked on my little ninja 250 caliper.