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Sticky Piston


Reignman's picture

By Reignman - Posted on 27 January 2014

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

Folks,

I have recently had probs with a piston in a set of Juicy 5's that wont fully retract...

I bleed some fluid to help increase the gap, and always ensure (yeh, right) that I remove the pad prior to applying anything.

Just wondering what people use for lubrication??

I used a little bit of silicon spray in a syringe just around the pistons, which helped, but I am worried that it may attract dust (I am in the NW)

Ideas??

Ps. And no I will not be buying a set of brakes from other reputable brands in the interim, so don't type it!

pancakes's picture

Give it a good clean with brake cleaner and cycle it several times to clean the cylinder. If its not scored and the seal's OK it should do the trick.

Failing that, you can get decent Shimanos with a happy meal these days. Eye-wink

hawkeye's picture

If you really do get stuck (boom-tish), Avid has rebuild kits for calipers with all the O-rings and needed and a replacement piston.

That said, I've been able to fix sticky pistons most times with brake cleaner and cotton buds (the things you clean your ears with) to get the grunge off the outer wall of the piston. Just push one piston out at a time using a tyre lever to hold the other in place and cipe it with a bud soaked in cleaner. Be careful not to push too far or the caliper will gulp air.

Prevention is better though, a light spray with a (very) soft hose through the caliper during the post-ride clean will help stop it building up.

I thought the deal at maccas was with the pancakes? Sticking out tongue

Flynny's picture

Take brake pads out and carefully pump the piston out a little. As Hawkeye says be careful not to go to far otherwise it full rebuild time.

Use a "dry" silicon spray type lube to lube up the side of piston. Use a small open ended or ring span to gently work he piston back in. repeat Until it loosens up.

Wipe any excess lube off, be thorough. Put pads back in. Bobs your uncle

Reignman's picture

Thanks folks, will try all mentioned and see which works the best.

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