Revision/Rebuild with Bleeding/Pumping

legsroses

.060 Over
Joined
Mar 6, 2012
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200
Hi in 2020 :)
I hope in your help :thumbsup:
Good Ride ;)

Usury of pads isn't regular (for cracks/furrows on some pistons), I tried with compressor for remove pistons however uselessly so I will use other tool. Any suggestions/tips/advice about as I should do

Know you which is model brand of our brakes calipers (both the double front nissin than only one rear brembo), so I could buy appropiate and correct kit for revision of them.

I need to do emptying/purge procedure (for remove old oil with air presence too) with subsequent pumping, which equipment suggest you/how proceed step by step for circuit abs system too.
 
be careful using air pressure to remove brake pistons it is dangerous!!!

you suggest well, I think so too, then I worn robust gloves.
however pressure didn't perform its function fully, so for some piston coming out while others for nothing.
I believe something blocked some of them, I don't know precisely why I think dirty/oxide.
 
If the piston is seized in the caliper, you could use a grease gun to remove it. The trick is to find fittings compatible with the caliper. Take care to ensure all the grease is removed once piston is forced out.
 
If the piston is seized in the caliper, you could use a grease gun to remove it. The trick is to find fittings compatible with the caliper. Take care to ensure all the grease is removed once piston is forced out.

I tried with grease, white lithium with teflon specifically, but didn't occur nothing. If it should be wrong then suggest kindly you other type, so nitro thinner for remove it or is better something else. Could you suggest me some tool type like plier or other like so.
 
Too bad you didn't first remove the brake pads from the caliper while it was still on the bike then pump the pistons out of the bores with the master cylinder. Each of the pistons would have bottomed out on the rotor so you wouldn't have to clamp them individually to get them out.

With the caliper on a bench disconnected from the bike, a grease gun should work. You have to clamp the pistons that aren't seized to get the seized one out though.

Here are a couple of videos for reference.



This may not work if the seal is leaking badly.
 
I fully endorse so hitch wouldn't be present, I hope however will solve it with these hints. So for now bye bye for you with everyone too :)
 
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With the caliper on a bench disconnected from the bike, a grease gun should work. You have to clamp the pistons that aren't seized to get the seized one out though........
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@legsroses Did you reinsert the pistons that came out and clamp them (or wedge with a block of wood) to prevent those from coming out again? The stuck ones will then be forced out with air or grease. If one or more is out you won't get any pressure building to remove the stuck ones.

I would not trust thick gloves using air! Those pistons come out amazing fast and hard and can easily crush or remove a finger. I put thin blocks of wood (about the thickness of one and a half or two brake pads) and wrap the cylinder in a heavy towel- then apply air with caution. If you do it right they'll stop on the wood and be out far enough to then pull them out by hand.

Grease is the safer method that @Gregger mentioned.
 
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If one of the pistons is stuck, you can use a block of wood and a large C-clamp to try and force the piston back into the cylinder. This should break loose what ever is binding it. This is how I have worked on stuck pistons in the past. Those pistons should be able to be removed by hand unless rusted.
 
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@legsroses Did you reinsert the pistons that came out and clamp them (or wedge with a block of wood) to prevent those from coming out again? The stuck ones will then be forced out with air or grease. If one or more is out you won't get any pressure building to remove the stuck ones.

I would not trust thick gloves using air! Those pistons come out amazing fast and hard and can easily crush or remove a finger. I put thin blocks of wood (about the thickness of one and a half or two brake pads) and wrap the cylinder in a heavy towel- then apply air with caution. If you do it right they'll stop on the wood and be out far enough to then pull them out by hand.

Grease is the safer method that @Gregger mentioned.

I didn't reinsert none, for not even one is unlocked. Only couple were coming out, so slowl not much too. Indeed gone out merely two pistons but however for less of 1mm. In hindsight if weren't blocked I could seriously hurt some fingers.
 
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