Brake pistons and stuck retaining pins

[Tubz1983]

Replacing pads and discs before MOT. Right hand side caliper is done but the pistons did not come out evenly?! Top two pistons are ok but bottom two dont pop out as much, particular on one side, in fact it hardly moves?!
Is this normal? Im guessing not...

[Bretty]

Do this...

put a spanner or bock of wood between the moving calipers so you can force out the stuck pistons, then clean and grease as per the video. That should sort it. I'd guess your seals are not in too bad a state if the other pistons are moving.

[Fazerider]

Possibly just crud on the piston. You can clean them by pushing them out a bit, one at a time, by using tyraps/ thin G-clamps/etc. to hold the ones you’re not working on in the cylinders out of the way. You’ll need to rotate the piston to get all the muck off.
Possibly, the seals need changing… particularly if you find the brakes drag excessively. Either way, if you’re doing it yourself, a brake piston tool makes it a much easier job.

[Tubz1983]

Thanx guys il get to it tomorow

[tommyardin]

Thanx guys il get to it tomorow

Thanks for the post guys and to Del Boy.


Just been out and done my brakes, after the video that was posted it leads on to another of Del's videos.
Cleaning the calipers not as a maintenance task, but, just as a part of your cleaning routine.
I spun my front wheel by hand before the clean up and it spun about 4 or 5 revolutions before coming to a stop, back wheel is difficult cos of the chain drag.
Anyway after following Del's video my front wheel no spins 10 or 11 revolutions before coming to a halt, obviously removed a lot of brake dust and crud from in the caliper.
The rear is harder to quantify because of chain drag but as cleaning the front has a least doubled the number of revolutions I am assuming that the rear has now improved as well.
One thing Del does say is 'DO NOT USE A PRESSURE WASHER ON THE CALIPER' because water can get forced under the piston seals and contaminate the hydraulic brake system.


The whole operation took about 20 minutes plus I gave it ten mins to start with to allow the hose water to help soften up the crud.

[Tubz1983]

Yea ive watched it as well and got hold of some clamps fir the working pistons

[Gnasher]

Do this...

What is this bloke on  rotate your pads, so they last a bit longer   this is going to end in  DON'T do it.


The fact the pads are worn uneven is telling you something is wrong especially with any opposed piston caliper.  Basically one side of the caliper the pistons have started to seize or the the pads are seizing in the caliper body.  Pads wear to the disc turning them around means they aren't now parallel to the disc and therefore have reduced surface contact and until they wear back in reduced brake force, depending on the condition of any given disc this could mean almost no brakes!   This is madness to save a few quid or because you don't have the know how or can't be bothered!

If you pistons are sticking any quick fix i.e. pumping them out against something to free them is just temporary they WILL seize again.

If your pads are wearing at uneven rates or at angles (front/back - left-right) there's something wrong.  I've made many post here over the years there's no short cut here and there're many reason why they wear this way, cheap or poorly fitting pads (EBC were and still are terrible on certain bikes) lack of maintenance, wrong maintenance. 

U tube is full of this stuff but this is almost the worst I've seen, it's bloody dangerous

[darrsi]

Do this...

What is this bloke on  rotate your pads, so they last a bit longer   this is going to end in  DON'T do it.


The fact the pads are worn uneven is telling you something is wrong especially with any opposed piston caliper.  Basically one side of the caliper the pistons have started to seize or the the pads are seizing in the caliper body.  Pads wear to the disc turning them around means they aren't now parallel to the disc and therefore have reduced surface contact and until they wear back in reduced brake force, depending on the condition of any given disc this could mean almost no brakes!   This is madness to save a few quid or because you don't have the know how or can't be bothered!

If you pistons are sticking any quick fix i.e. pumping them out against something to free them is just temporary they WILL seize again.

If your pads are wearing at uneven rates or at angles (front/back - left-right) there's something wrong.  I've made many post here over the years there's no short cut here and there're many reason why they wear this way, cheap or poorly fitting pads (EBC were and still are terrible on certain bikes) lack of maintenance, wrong maintenance. 

U tube is full of this stuff but this is almost the worst I've seen, it's bloody dangerous

I just watched this and the main thing that struck me as being a bit naughty was jacking up the bike and putting a lot of pressure onto the side stand and making the bike very unstable.
I wonder if anyone's ever tipped their bike over when trying that?