caliper help please

[Airman]

Just another bit to add.
As the pads wear, the piston comes out and stays out more, exposing more of it to the elements.
These things should be able to slide in and out with a finger, once the seal has been lined up.
Either the caliper bore or the piston is not cleaned properly, corroded etc or... you pushed it in off square causing it to lock in place.
Also, the shoulder that the seal sits in also needs to be cleaned properly to allow a seal , but not grip too tight.

Either way, they need to come out again.
I got my rusty ones out by pumping the lever, holding it and tapping the caliper (or eventually beating the shit outta it) to "nudge" the piston out. took me a day or two of arsing, had the caliper in a bag while doing it, so eventually when it came out with an unmercyfull bang, the bag caught all the fluid and piston.

[Wolffcastle]

Eh.. did you bleed the master cylinder?? Crack open the banjo going to the master cylinder while the lever is held in. Repeat till theres no bubbles...Try blleding as normal then

[the landshark]

its important to clean the white shite out of the grooves the seals sit in, it presses the seal against the piston so's it wont move, as airman says, you should be able to press them in with a finger and thumb

[viffer750]

Originally Posted by dwyermcalaster

ye lads think the pistons might be fucked got them out but cant get them in now seem to be siezed , any body any ideas what other caliper would fit a fz750

discard the outer dust seals (they cause more trouble than they're worth), clean the pistons properly and they should slide back in easily.

[motthomas]

Originally Posted by viffer750

discard the outer dust seals (they cause more trouble than they're worth), clean the pistons properly and they should slide back in easily.

If your suggesting getting rid of the dust seals so the piston only slides on one seal then your mad!
To view pics on this biker's forum - your post count must be 2 or greater.
Thats a one way ticket to a jammed and scored piston and cylinder! Very bad "advice" there IMO. Bike manufacturers put those seals in for a reason.
To view pics on this biker's forum - your post count must be 2 or greater.
You suggesting you know more than the engineers in Honda/Suzuki/etc?
To view pics on this biker's forum - your post count must be 2 or greater.

[Motormike]

In Offaly if you need any help with them. Let me know.

[Motormike]

Dont discard any seals. THEY HAVE A VERY IMPORTANT PURPOSE and I would not risk leaving them out.

[the landshark]

Originally Posted by viffer750

discard the outer dust seals (they cause more trouble than they're worth), clean the pistons properly and they should slide back in easily.

Gud jaysis what a load of shite, nothin to protect the seals from grit, and no front brakes when you need them
@the op
pull out the pistons, use wet and dry sandpaper(600-1000 grit) on the pistons, wetted with diesel and a brake caliper hone on the cylinders,
use a dremel brass wire brush to clean the grooves,
if the pistons and seals are fucked get new ones, horsepower do seals and pistons for about €25 per set,
and make damn sure you put the fluid seals in the right way round
To view pics on this biker's forum - your post count must be 2 or greater.