Getting pistons out?

[Mole_C]

Im trying to replace some seals and do some cleaning but already have my brakes off so can't use the brakes to push the pistons out. Is there any other easy way to get them out without reconecting and filling with brake fluid again?

Thanks

[paturoa]

compressed air, but be real careful cos it will come out a million miles per hour

if u dont have a compressor, then even the old lung power is normaly enough, don't drink the brake fluid, its poisonous (sp?)

[Mole_C]

Yea i tried blowing through a hose and using a hand pump but didn't work, think i even broke the pump with the pressure :shit: Im assuming that u put it in the hole where it connects to the brake line normally?

[paturoa]

Yeah where the brake line goes into the caliper.

were they working OK before?

Otherwise take the caliper and a rag to wrap around it to the nearest garage and get them to blow it out with compressed air. Make sure that it is wrapped well as the piston will make a fast exit if it is jammed in there!

[Mole_C]

yea they were working fine, might just take them in to cycletreads. Thanks for the help anyway

[Mole_C]

I did it myself at home in the end, reconected them and pumped away. Took me a while but they work brilliantly now :yes: Even got the front to slide when i was testing them. Im happy now :yes:

[paturoa]

So you replaced the seals? and checked for pitting?

[Satch]

Yeah mate, this is worth doing, just did them on Sallo's bike not long ago and it improved the braking 5 fold, they were real stuk, took a bit of getting them out tho, just used a rag in the caliper to "catch" them and compressed air to get them moving

i can give you a hand if you want

[The Stranger]

I did it myself at home in the end, reconected them and pumped away. Took me a while but they work brilliantly now :yes: Even got the front to slide when i was testing them. Im happy now :yes:

Um, you have a torque wrench and loctite aye?
We don't want a repeat of the great caliper hunt.

[scumdog]

Um, you have a torque wrench and loctite aye?
We don't want a repeat of the great caliper hunt.

Yeah, had that happen once, the BIG bolt holding the two halves together kinda unwound itself, first warning was the brrrrrrrr noise of the head of the bolt hitting the spokes of the front wheel!!!!!:gob:

The pump-jockeys at the gas stations freaked out when they saw the caliper tied to the handle-bars with a crescent taped between the disc-pads to stop them popping out if I used the front brakes.
(I was too scared to use them)

[Ixion]

They never did find that caliper

[imdying]

You don't need a torque wrench and loctite to prevent that from happening:laugh:

[The Pastor]

How do u put them back in???

[Motu]

For really stubborn pistons we use a lever action grease gun - they put out 10,000psi.

[Crasherfromwayback]

For really stubborn pistons we use a lever action grease gun - they put out 10,000psi.

Shit hot tip! A lot safer than air too.....never used that Motu, but I will!

[The Pastor]

For really stubborn pistons we use a lever action grease gun - they put out 10,000psi.

For putting pistons back in?

[Crasherfromwayback]

For really stubborn pistons we use a lever action grease gun - they put out 10,000psi.


For putting pistons back in?

If everything's clean enough....your hands.

[The Pastor]

If everything's clean enough....your hands.

I cant put it back in! :( why not

[imdying]

Just push them back in with your hands, straight. Do not cock them over slightly or you will royally fuck things up. Use a little brake fluid to lube it.

[The Pastor]

Just push them back in with your hands, straight. Do not cock them over slightly or you will royally fuck things up. Use a little brake fluid to lube it.

oh no, I did use brake fluid to lube things up, but it still wasnt going in, i used a vice to cram it back in and nothing was happing till it just sorta snapped back in.... is this bad? I now when i've hooked it all back up nothing is happening when i pull the brake lever.... I think its just a big air lock so ive taped up the handle to let all the air raise to the top......

[imdying]

It is only likely to be bad if you've either scratched the working surface of the piston (it'll leak pretty quickly), or you've snapped part of the inner caliper housing off (it'll leak pretty quickly). If it is not leaking, you're probably ok. You really shouldn't need a great deal of force to reassemble them, just the right force in the right place. I'm guessing that if it doesn't want to bleed up, you've let the master cylinder run dry, and it needs tp be primed. Use the search function, I've mentioned how to fix this a few times.

[The Pastor]

Yeah ive got it fixed now, it was a giant air lock. I tired for 2hrs to put it in nicely but i couldnt get it....... how do u put the pistons in nicely?? To get it out i had to hook it up and pump the brakes to make it come out.