sticky piston dilemma

Icyseanfitz

im back again with another of my daily problems front brake (avid elixer 5) is acting up, ive pushed the pistons back so that there flush but when i pull the lever and let go one of them doesnt go back in fully, so i take it thats a sticky piston?

how do you go about fixing these? was hoping for a spin tomorrow so i might drop into my mechanic before hand to see if he can do a quick job on it but id like to know how to do it myself as well,

what brakes are the boards "pro's" using getting fairly sick of my elixers and there problems tbh

Roger Hassenforder

this thread is replete with opportunities for double entendres!
(havent a clue about the brakes though)

kona

Roger Hassenforder wrote: »

this thread is replete with opportunities for double entendres!
(havent a clue about the brakes though)

Its just your pads wearing, as long as they aint rubbing and are working I wouldnt worry.

Holyboy

What you want to do(and it's taken me far too many years to figure this out)is pop out you're wheel and pads, pull the lever gently to move the piston out a bit get what ever fluid is in the braking system and lube the piston with it, then work it in and out pushing in the piston and pulling the lever blade to push it back out, just don't pop the piston out of the caliper, that's a nightmare, haha.
A few minutes of working it in and out should sort it, then a final push into the caliper, degrease, fit everything back on and set the brake up, simples:D

Icyseanfitz

Holyboy wrote: »

What you want to do(and it's taken me far too many years to figure this out)is pop out you're wheel and pads, pull the lever gently to move the piston out a bit get what ever fluid is in the braking system and lube the piston with it, then work it in and out pushing in the piston and pulling the lever blade to push it back out, just don't pop the piston out of the caliper, that's a nightmare, haha.
A few minutes of working it in and out should sort it, then a final push into the caliper, degrease, fit everything back on and set the brake up, simples:D

great advice thanks, i take it when you push the pistons out to a certain amount you get some of this brake fluid leaking out? and then you lube it up with that yeah? will do myself if it happens again, just going to get my mechanic to do it for me tomorrow though as i need it done quick with no fuss

Icyseanfitz

kona wrote: »

Its just your pads wearing, as long as they aint rubbing and are working I wouldnt worry.

wouldnt bother me if it was working grand but its not, the piston has the pad rubbing the rotor so the wheel wont spin freely

Holyboy

Nope, no fluid should leak out, if it does either the seal is damaged or you have pushed the piston out too far!
You need extra fluid to lube it up.
Suggest what I've said to your mechanic, I only know of two others that do this and I showed both of them how to do it, but maybe others have figured it out too!
With the pretty much universal post mount system these days, disc brakes are so easy to get right, Jebus and thank God the IS fitting is nearly a thing of the past, hours of shims and facing tools, wasted, I could have been out picking up women:p

sean_d

Icyseanfitz wrote: »

i take it when you push the pistons out to a certain amount you get some of this brake fluid leaking out? and then you lube it up with that yeah?

NOOOOO!
You definitely don't want any brake fluid leaking out from behind the seals - if that happens, you've got far bigger problems than a sticky piston.
You'll need some of the correct type of brake fluid from another source (ie, a bottle of it) and drop it on from the outside.
Be careful, Avid uses DOT fluid, which is highly corrosive and damaging to paintwork. Recommend taking the brake off the bike to do it, as it'll also make it a bit easier to work the pistons that way too.

Holyboy

sean_d wrote: »

NOOOOO!
You definitely don't want any brake fluid leaking out from behind the seals - if that happens, you've got far bigger problems than a sticky piston.
You'll need some of the correct type of brake fluid from another source (ie, a bottle of it) and drop it on from the outside.
Be careful, Avid uses DOT fluid, which is highly corrosive and damaging to paintwork. Recommend taking the brake off the bike to do it, as it'll also make it a bit easier to work the pistons that way too.

DOT fluid isn't that bad, I've had it in my eyes, in my mouth and up my nose!
I've never seen it do any damage to frame or fork paint work, the worst I've seen is bar logos disappearing, but it is a good idea to clean it off properly and strangely plain ol' water is supposed to be the best for it.

sean_d

Holyboy wrote: »

DOT fluid isn't that bad, I've had it in my eyes, in my mouth and up my nose!

I don't think I want to ask how you managed all that??? :eek:
It does turn skin a funny yellow colour though, but a few weeks of looking like Bart Simpson never hurt anyone

Holyboy

Can't say I've ever noticed that but my hands are pretty much black at the best of times even after a few scrubs with a nail brush so I guess I wouldn't notice!
Just can't use those bloody gloves,I like to feel at one with the bike,haha.
I've had just about every bike related thing fly at my face over the years,last week was a new one, I was cleaning out a tyre and a tiny piece of glass flew out right into my eye, NOT PLEASANT AT ALL:mad:

Icyseanfitz

was thinking it would be a bit odd to leave the brake fluid in the line escape for lubing purposes alright, must go about getting some oil then, have to go about getting a bleed kit as well, thanks for the help lads

zil

..............wtf

The vast majority of modern brakes including yours have self adjusting pistons. They move outwards as use them and your brake pads wear out to ensure that you can brake consistently as the brake pad thickness reduces.

Icyseanfitz

zil wrote: »

..............wtf

The vast majority of modern brakes including yours have self adjusting pistons. They move outwards as use them and your brake pads wear out to ensure that you can brake consistently as the brake pad thickness reduces.

and what happens when the piston moves out when you pull the lever but doesnt move back to its original position after youve finished braking? constant rotor rub on that pistons side thats what, from what ive heard elixers are pretty notorious for "sticky pistons" if not maintained every couple of rides

Tenzor07

Just bring it down to your mechanic, he will do a service of the pistons and bleed the brakes/top up the oil...

Once you do that, put the Avid's up for sale and get a nice shiny set of Shimano XT brakes!

Icyseanfitz

heard magura brakes are pretty good as well? i will be taking this particular problem to my mechanic as i dont own a bleed kit and my track record with hydraulic brakes aint great

Tenzor07

Just get the Shimano, your LBS is more likely to be able to get them into stock, Magura are fairly rare apart from being OEM spec on bikes...

C3PO

Tenzor07 wrote: »

...... Magura are fairly rare apart from being OEM spec on bikes...

Icyseanfitz will have 'em so!!;)

Lemag

Icyseanfitz wrote: »

heard magura brakes are pretty good as well? i will be taking this particular problem to my mechanic as i dont own a bleed kit and my track record with hydraulic brakes aint great

Go on Icy. What could possilby go wrong? £35.99

Biopace

Lemag wrote: »

Go on Icy. What could possilby go wrong? £35.99

Lemag

Biopace wrote: »

So you read this

sean_d wrote: »

NOOOOO!
You definitely don't want any brake fluid leaking out from behind the seals - if that happens, you've got far bigger problems than a sticky piston.
..
Be careful, Avid uses DOT fluid, which is highly corrosive..

and then this;)

Icyseanfitz

Lemag wrote: »

Go on Icy. What could possilby go wrong? £35.99

sure bleeding brakes is easy as making a pie this would be me after 10 seconds

ps. turns out making a pie aint so easy

Icyseanfitz

Tenzor07 wrote: »

Just get the Shimano, your LBS is more likely to be able to get them into stock, Magura are fairly rare apart from being OEM spec on bikes...

quick question about the shimano brakes, nearly all the ones ive looked at seem to be post mount, is it easy to convert them to is mount?

kona

Icyseanfitz wrote: »

quick question about the shimano brakes, nearly all the ones ive looked at seem to be post mount, is it easy to convert them to is mount?

you can get an adaptor.

Sometimes all the time avid brakes are a pain in the ****ing hoop and just refuse to be set up correctley. pity as elixer have such great potential.

As has been said get shimano. Dont bother with magura.