Topic: “Crud in a Caliper”

[BenelliSEI]

Started refurbishing the brake caliper on my early ‘69 cb750. Piston has absolutely no corrosion. I pushed it out using a fitting I made years ago. It’s the gland nut from an old steel line. I drilled and tapped it to take a std. grease fitting. Close the bleed nipple, screw it in, and attach a grease gun. Few pumps, and the piston pops out.

It always amazes me the amount of crusty debris the I scrape out from behind the seal! The pile in the photo all came out of this caliper, from under the seal, in the groove. Scrape 99% of it out, before a final polish with the Dremel tool shown. Don’t be tempted to use just the Dremel. It will only polish the crap and your new seal will be way too tight on the piston, and will leak. I’ve made the mistake.....

[HondaMan]

Smart move!
I only polish the piston with Scotchbrite, using a little screwdriver to get in the corners with the cloth.
More often, I find the brake puck crudded into place on those 30-year sleepers. Those can be REAL hard to get apart. The worst one went into a 2-week soak of solvent mixed with oil to loosen the puck enough to grease-jerk out the piston.

[ekpent]

Pretty typical of all the crud behind the seal on some sleepers I have done also. I also like all the wonderful gooy crud and chud that was behind the piston when I pop them out. I've been lucky usually using a working master cylinder to get the pistons out. Only had to grease gun a couple of them.
  As Hondaman mentioned the old brake pad can be the real problem sometimes.

[BenelliSEI]

This one was incredibly clean, piston spotless, but still packed behind the seal.

[spotty]

i saw the title of this thread and immediately though " Mmmmm, German handicapped porn " but thats just how my mind works

[Stev-o]

I recently cleaned the caliper on my K5, it had become stuck after not being ridden about a year.  I pumped the piston out before disconnecting the hard line, it really wasn't stuck, just would not go back in. A quick cleaning and it is working great again.

The compressed air trick is the most exciting way to remove a stuck piston!

[ekpent]

I recently cleaned the caliper on my K5, it had become stuck after not being ridden about a year.  I pumped the piston out before disconnecting the hard line, it really wasn't stuck, just would not go back in. A quick cleaning and it is working great again.

The compressed air trick is the most exciting way to remove a stuck piston!

"Put your eye out kid"     I learned to wrap it in a rag first doing that the hard way and luckily the piston didn't get damaged.

[BenelliSEI]

I know a guy with a small piece of finger missing..... Guess what he was doing Steve-o?

[craz1]

Ouch!. I use the grease gun method after blowing a piston clear across the room and bouncing off several walls

[HondaMan]

Ouch!. I use the grease gun method after blowing a piston clear across the room and bouncing off several walls

Yeah.
I only did that once.
Took a while to find it afterward, even though the dent in the wallboard showed where it first hit.

[BenelliSEI]

I recently cleaned the caliper on my K5, it had become stuck after not being ridden about a year.  I pumped the piston out before disconnecting the hard line, it really wasn't stuck, just would not go back in. A quick cleaning and it is working great again.

The compressed air trick is the most exciting way to remove a stuck piston!

That sticking you describe is just that crap building up to the point the seal is too tight on the piston. On several occasions, I’ve cleaned out the groove and reused the same seal. Problem solved......

[Stev-o]

I know a guy with a small piece of finger missing..... Guess what he was doing Steve-o?

Using a chop saw?!

[bryanj]

Title of this post strikes me as a new cuss phrase!

Been saying for years a dremel dont shift it