Changing brake pads

[ShaunGASGAS300]

Any advice on the best tools to use for prying open Brake cylinder to get new brakes in.
Just took me an hour using a screw driver one sockets ect. Any better tools or advice?

[Beerbelly]

Water pump pliers are useful

[Dominic]

If they are sliding calipers you should be able to slide them open by pushing them gently against the brake disk. If they don't slide then they may need disassembly and greasing

[Dominic]

Greasing the pins on which the caliper slides I mean. Don't grease elsewhere

[ShaunGASGAS300]

Thanks guys.

May need to disable next time and geese up when i have time. I did eventually get them open enough to fit new pads in.
This is what they look like. It just took forever to compress the piston!

[Dominic]

So where it 'i' of the word 'caliper' is in the picture above is where 1 of 2 sliding pins are. If the caliper does not slide towards the wheel when you push on the flat part above the 'ra' of the word hydraulic then your pins are seized. Seized pins will shorten pad and disk life.

To fix this you need to take the wheel and caliper bracket off... clean and regrease the pins. While you are there you should clean the pistons and backing plates too.

[mudeevee]

So where it 'i' of the word 'caliper' is in the picture above is where 1 of 2 sliding pins are. If the caliper does not slide towards the wheel when you push on the flat part above the 'ra' of the word hydraulic then your pins are seized. Seized pins will shorten pad and disk life.

To fix this you need to take the wheel and caliper bracket off... clean and regrease the pins. While you are there you should clean the pistons and backing plates too.

I can feel a club night demo coming on Dom! You up for it?

[Dominic]

I am no expert any many others will be much more competent than I (G-Bru still laughs at my mechanic skills) but happy to give it a go!

[muckybear]

Usually the major cause of the problem is dirt and corrosion in the dust seal grove pushing the dust seal, Not the hydraulic seal, onto the piston making it difficult for the piston to move. This can often be identified by a brake that when applied gently does not slow you but with a little more pressure grabs a bit all of a sudden.
Solution:- Order up "Caliper Repair Kit" or dust and hydraulic seals, remove Caliper, remove pads, remove pistons. Either pump out with brake lever (Trickier with dual piston calipers) or easier with compressed air. *** Warning make sure fingers are out of the way, you can easily lose a finger.
Do not split calipers that are made of two bits (Couple of very tight bolts) (Opposing Piston jobs rather than sliders) It won't help and you will regret it.
Remove the old seals carefully. The hydraulic will come out easily, the dust seal the thinner one near the top of the bore can fight back at being evicted.
Clean out the dust seal grove very thoroughly, you will need a scriber or small sharp screwdriver, take your time and make sure there is no white corrosion remaining. Clean the pistons with Solvo Autosolv or similar. I completely strip the caliper and wash it in the sink with Fairy, blow off with an air gun and dry in a warm oven. When reassembling make sure there is "Red Rubber Grease" in the dust grove. This keeps the muck and corruption out. It has to be a "Rubber Grease" as the dust seals are not Neoprene and grease rots rubber. Reassemble & refit, road test, but be careful as you will have forgotten what a good set of brakes feel like.
Enjoy

Chris Avery & Teddy

[Weet-rider]

Good info from Dom and Chris there.
If I could also add a word of caution regarding phenolic (plastic) pistons which can usually be identified as being black with a thin metal cap over the exposed end.
These are brittle and the ends crumble away easily, more so with heat and age so do not be tempted to use any tool to help ease them out or squeeze them back in.
Dave