Brake piston cap fallen off

**ColonelSponz** · 13th August 2010, 20:51

Sup,

So, I was replacing the front brake pads on my cibby today (a wee 250R) and as I was doing so the 'cap' over one of the pistons came off. Now I wondered if I could just glue it back on using any old metal compliant adhesive or if I needed something special.

Cheers in advance.

**Warr** · 13th August 2010, 21:23

Originally Posted by ColonelSponz

..... the 'cap' over one of the pistons came off......

More info required .. or perhaps a picture or 2 ??

**Max Preload** · 14th August 2010, 11:19

It'll be a cosmetic cover. Ados F2.

Edit: I'm assuming it's on the outside of the caliper, not the synthetic insert in the piston itself that pushes against the back of the pad. You'll need something a bit higher temperature than Ados if it's that insert.

**ColonelSponz** · 14th August 2010, 19:32

Pretty sure it is cosmetic. I've ended up using just a normal araldite to glue it on.

It DOES push against the back of the pad but seems to be more of a surface between the piston itself and the pad.

Another problem has arisen however and that is that this same piston is refusing to be pushed back into its 'hole'. The other has gone in fine. I've even tried using a g-clamp but nadda movement resulting. Any help on that?

**one fast tl1ooo** · 14th August 2010, 19:33

Just stick it back in the pad will hold it in

**Squiggles** · 14th August 2010, 23:50

Originally Posted by ColonelSponz

Another problem has arisen however and that is that this same piston is refusing to be pushed back into its 'hole'. The other has gone in fine. I've even tried using a g-clamp but nadda movement resulting. Any help on that?

Im going to make a scary guess that you havent taken the cap off the mastercylinder and its now full, leaving the fluid behind the other piston with nowhere to go... tell me im wrong.

**willytheekid** · 15th August 2010, 00:55

Hmmm....brakes, kinda important.

I would recommend you take the caliper completely off, drain all the fluid, check the piston seals are ok and then "carefully" reassemble the caliper and re-bleed the brakes.
If you try to force the piston back in with say a "g-clamp" you run the risk of damaging the piston seals or scouring the pistons or piston seats.
The last thing you want is to apply the brakes...and they lock on!
Take your time and search the Net for information for your particular type of calipers, there should be lots of info online to help you do the job correctly and safely.
Doing the work yourself can either save you lots of money...or cost you lots of money, just depends on how you do the work

**Max Preload** · 15th August 2010, 07:10

Originally Posted by Squiggles

Im going to make a scary guess that you havent taken the cap off the mastercylinder and its now full, leaving the fluid behind the other piston with nowhere to go... tell me im wrong.

You're probably wrong unless some cretin has topped up the fluid between pad changes.

But he should replace the fluid at every pad change though anyway.

**ColonelSponz** · 16th August 2010, 13:23

Yes, you are wrong.

Thanks for the tips, I'll try taking the caliper off and let you know how it goes.

Just seems like a really simple job that anyone should be able to do.