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Seized caliper piston. Is it worth trying to free it

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I have been having brake issues for a while now in that sometimes its really good and sometimes not. Today Is a not and applying the brake I can see one piston moving the disk over to the other which is stationery.

So am I wasting my time messing with it? Is it worth paying a pro to sort it or just buy a new one?

What brake is it?
  • Author
What brake is it?
The back one! Sorry I couldn't resist that. Shimano SLX

it only takes a couple of minutes to fix. Just loosen the two bolts, move the caliper so that the pad which is not seized is against the rotor. Tighten the bolts.

Squeeze the brake lever. The fluid pressure will free the seized caliper.

Recentre the caliper.

Well it all depends on what you have,

are your brakes expensive to replace ?

A seal/piston kit, new fluid and bleed kit lets you strip and rebuild them ?

 

Personally I'd just buy new as my Shimano brakes (single sided) were less than £40 the pr, complete, pre bled and ready to fit. It would be a different story if they were expensive ;)

  • Author
Well it all depends on what you have,

are your brakes expensive to replace ?

A seal/piston kit, new fluid and bleed kit lets you strip and rebuild them ?

 

Personally I'd just buy new as my Shimano brakes (single sided) were less than £40 the pr, complete, pre bled and ready to fit. It would be a different story if they were expensive ;)[/QUOT

  • Author
Just looked on line and there are diffent ones so will need to check. Not interstted in stripping down as a total failiur after my messing could be painful. so will try the moving the caliper thing and see if that works.
£30 or so for a new calliper plus oil etc, new pistion kit about £9 each. Problem with calliper repair's if it doesn't work you have wasted money, at least with a new calliper you get new pads as well.

As long as a calliper uses the same pads in theory you should be able to fit aand use any of the SLX range.

Bikester £23.99 on sale at the mo.

  • Author
It would probably cost much more for bike shop to fix it and as I am not up to bleading will have to buy one already bled. just make sure the length is right.. Spent a lot over crimbo so trying to be good. tilll I pay my card off.
  • Author
just reakised, i think i has internally routed cables so diy replacement is off the table.

Had this problem in the past.

 

Remove the pads, remove the wheel.

 

Make a clamp from a piece of wood that sandwiches the ( moving piston ) and the outside of the calliper.

 

Push the moving piston in as far as you can. Tighten up the clamp you have made, this will stop the moving piston from moving.

 

Now, slowly press the brake lever to get the seized piston to move.

 

Get an old toothbrush and clean the protruding section of the piston(s) .

Push back in, repeat this process until the once seized piston is free.

  • Author
Had this problem in the past.

 

Remove the pads, remove the wheel.

 

Make a clamp from a piece of wood that sandwiches the ( moving piston ) and the outside of the calliper.

 

Push the moving piston in as far as you can. Tighten up the clamp you have made, this will stop the moving piston from moving.

 

Now, slowly press the brake lever to get the seized piston to move.

 

Get an old toothbrush and clean the protruding section of the piston(s) .

Push back in, repeat this process until the once seized piston is free.

Thanks.

I had sort of guessed it's a case of getting it moving without popping the other side out. Just figuring how to do it.

Cool, Never had much success using the rotor method. Found that the rotor was too flexible, and sometimes created a bit of a warp in the rotor.
  • Author
Cool, Never had much success using the rotor method. Found that the rotor was too flexible, and sometimes created a bit of a warp in the rotor.
I had thought of jamming a screwdriver between the disk and the caliper to stop the disk bending.

It a shame that you didn't live locally to me, as I would offer to help you.

 

Try the advice that Denis99 has kindly offered, but if you get really stuck, I have a new take off XT caliper that I would happily give to you, but I have robbed the pads from it. I needed a lever assembly in a hurry, and frustratingly had to buy the whole assembly as there was no UK stock at the time.

My one hesitation is that I don't know if the internal ratio assembly and bore of the master cylinder/lever is the same on SLX as it is on an XT assembly, which could mean that there might be an issue compatibility between the two systems.

 

Also by the time that you have bought a bleed kit and pads, it wouldn't really be a viable option.

 

Anyway, the offer is there if you want it.

 

brake_1.jpg

Edited by EddiePJ

  • Author
It a shame that you didn't live locally to me, as I would offer to help you.

 

Try the advice that Denis99 has kindly offered, but if you get really stuck, I have a new take off XT caliper that I would happily give to you, but I have robbed the pads from it. I needed a lever assembly in a hurry, and frustratingly had to buy the whole assembly as there was no UK stock at the time.

My one hesitation is that I don't know if the internal ratio assembly of the master cylinder/lever is the same on SLX as it is on an XT assembly.

Also by the time that you have bought a bleed kit and pads, it wouldn't really be a viable option.

 

Anyway, the offer is there if you want it.

 

brake_1.jpg[

Bleeding and fitting the pipes us a step too far for me

Not laughing at you SW, just the thought of Gubbins riding to the local shop, whilst using Hope brakes. :D

 

Gubbins, that wasn't meant in a derogatory way. :)

  • Author
Not laughing at you SW, just the thought of Gubbins riding to the local shop, whilst using Hope brakes. :D

 

Gubbins, that wasn't meant in a derogatory way. :)

Yeah i know.

I think sw thinks I am rich..

well there not 400 quid lol.;)

http://www.chainreactioncycles.com/magura-mt-trail-carbon-disc-brake-set/rp-prod156323

 

i just think given the extra waight all these bikes should come with mid point 4 piston brakes front and rear and 2 part disc rotors.

 

you also get lever adjust and brake point adjust which i would miss and have serviceable parts also.

 

ask the lbs if they have anything 2nd hand and px what you have ;)

  • Author
Joking side, its something thats been brewing for a while. I had this trouble before with brakes getting noisy and not working right after a wetting so put new pads in, and to get them in I had to really force one of the pistons back in, cleaned all the black dust out and they were fine for a while so it looks like the issue is there. I only have 3 options.. Fix it, pay someone to fix it or buy a new bike, (SW's choice as he always finds expensive ways around my issues), but I prefer to waste my cash on .. well, Junk, some would say!
Joking side, its something thats been brewing for a while. I had this trouble before with brakes getting noisy and not working right after a wetting so put new pads in, and to get them in I had to really force one of the pistons back in, cleaned all the black dust out and they were fine for a while so it looks like the issue is there. I only have 3 options.. Fix it, pay someone to fix it or buy a new bike, (SW's choice as he always finds expensive ways around my issues), but I prefer to waste my cash on .. well, Junk, some would say!

well you will have to spend 6k plus to get high end anything on a new bike so them hope brakes are cheap compared to that at 300 quid for 2 but you can also then put them on a new bike if the stock ones are crap be serviceable last longer be more adjustable than low end stock ones.

 

i have avid xo trail on my bike but the rotors that came with it was crap even on a 6k bike so they had to go as was getting so hot i just warped the crap out of them but not had any problems since i fitted hope 203 rotors front and rear as was about 40 quid each for just new rotors plus rear adaptor.

  • Author
well you will have to spend 6k plus to get high end anything on a new bike so them hope brakes are cheap compared to that at 300 quid for 2 but you can also then put them on a new bike if the stock ones are crap be serviceable last longer be more adjustable than low end stock ones.

 

i have avid xo trail on my bike but the rotors that came with it was crap even on a 6k bike so they had to go as was getting so hot i just warped the crap out of them but not had any problems since i fitted hope 203 rotors front and rear as was about 40 quid each for just new rotors plus rear adaptor.

I won't ever spend 6 killion pounds on a bike.

i got it for 3500 of ebay with 160 miles on it the guy travels 3 times that to deliver it for 100 quid pmsl ;)

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