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[Closed] Formula Oro piston extraction...

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[#2331009]

How easy is it to pull them out once they're pretty seized/stubborn?

I've seen folk use air to blow out car pistons on da toob of you...looked well easy, but i have no access to compressed air.

Is there a specific tool?

Ta muchlee in advance of the flood of helpful replies.
Stan.


 
Posted : 02/01/2011 6:12 pm
 RicB
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Compressed air works but has the danger of blowing DOT vapour in your face- not nice!

I found the easiest way was to extract one piston at a time by holding one piston back in the caliper with a spanner and pumping the lever. Disassemble caliper, sort/replace seals & piston, rebuild, rough bleed then repeat for other piston

Bit long winded but I cracked a piston trying to hold it with pliers.


 
Posted : 02/01/2011 6:56 pm
 RicB
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Track pump with football inflator adapter should give plenty of pressure if you want to try the air pressure trick


 
Posted : 02/01/2011 6:59 pm
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I got a slightly larger diameter bolt that I screwed into the piston. In other words the bolt cuts a thread into the piston. It doesn't matter as the piston walls are thick enough to take it (its basically a cylinder with a blocked end). Once its in far enough then just pull it out.
This avoids damaging the side of the piston trying to pull it out with pliers. I'd doubt there would be enough showing to get a proper grip this way.


 
Posted : 02/01/2011 7:26 pm
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Nice one, people!
Some good stuff to mull over...
Muchas gracias.


 
Posted : 02/01/2011 7:37 pm
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UPDATE:

1) track pump w/ football adapter = not a good enough seal/pressure.
2) Bolt trick = composite material of piston is crumbling, (and finally rotating), but it's too seized.

Will rebuild/use lever and see if that will work now that the pistons are at least rotating in their bores....


 
Posted : 02/01/2011 8:58 pm
 RicB
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Try using a small bit of inner tube with a pinprick hole to seal the adapter?


 
Posted : 02/01/2011 9:15 pm
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Conveniently brakes come with their own high pressure piston moving tool.


 
Posted : 02/01/2011 9:40 pm
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Flathead screwdriver and a hammer, i'd wear safety glasses if i did it again though, DOT 4 bloody stings.

Obviously the piston wont be re-usable


 
Posted : 02/01/2011 11:52 pm