Seized brake pistons / calipers

[Icemaestro]

Hi,

Have tried to search but nothing coming up. Last bled calipers, cleaned pistons and replaced seals on my nc30 in 2015, bike then went into storage in 2016. Getting it going again brakes are seized on. Freed up a little with a bit of movement - my query is (as 1) I hate bleeding brakes and 2) the fluid is clear as anything) is there anything I can do to unseize them without needing to re bleed them?

On a side note how often do people replace piston seals? No ice or salt on the roads where I am, bike lives nice and dry in a garage (albeit has a good layer of dust and a bit of sawdust!).
And final query where is the current cheapest place to get pistons from if I needed to? I remember them being a little corroded and not being perfect when I put them back in.




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[magg]

Un-seizing and re-bleeding are un-related processes. You may be able to free up the pistons simply by pushing them back into the calipers and then pumping them out, a number of times. Place a spacer, of similar thickness to the disc, between the pads so that the pistons do not pop out.

[Neosophist]

rubber seals deteriate from age and wtih brake fluid etc, your mileage may vary... as an example my 94 rmx250 still has its original pistons and seals in it but its an offroad enduro bike (non road version) so doesnt get ridden on public roads and stuff and some unexpect failure wouldnt be the end of the world for what i use it for.

for the cost and for piece of mind id probably hcange the seals every 5 - 10 years as part of a brake service / check.

pistons can last pretty much forever if they dont corrode / sieze up.

[Yakama]

If they are seized you could try something like this to move them and try and free them off without splitting the calipers though that may be difficult

https://rover.ebay.com/rover/0/0/0?mpre ... 1718534343

If they are really stuck you will need to split them and most likely need this tool, they are great

https://rover.ebay.com/rover/0/0/0?mpre ... 2395858783

[Yakama]

You can get new pistons here but not cheap

https://titanclassics.com/?post_type=product&s=Vfr400

[moforockband]

The brakes shouldn't be seized in 2 years?? Did you use rubber grease and brake fluid when installing the seals? Make sure you clean out the grooves behind the seals on service as clean as a whistle to minimise aggro. If you used genuine seals 2 years ago then you won't need to buy any more, just suss out what is the problem (probably corrosion behind the seals) :)

[Icemaestro]

The brakes shouldn't be seized in 2 years?? Did you use rubber grease and brake fluid when installing the seals? Make sure you clean out the grooves behind the seals on service as clean as a whistle to minimise aggro. If you used genuine seals 2 years ago then you won't need to buy any more, just suss out what is the problem (probably corrosion behind the seals) :)

Thank ou for the responses. I did use red rubber grease and brake fluid (initially just grease but remember finding the pistons wouldn’t go in until I had covered in brake fluid). I did clean out the grooves, though maybe not clean as a whistle - I remember an hour or two of sitting with a safety pin scraping the crap out! If corrosion behind the seals, assume I would need to split the calipers open and re bleed? (Will try just pulling them off and pumping in and out a bit first, thanks :-))


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[Icemaestro]

If they are seized you could try something like this to move them and try and free them off without splitting the calipers though that may be difficult

https://rover.ebay.com/rover/0/0/0?mpre ... 1718534343

If they are really stuck you will need to split them and most likely need this tool, they are great

https://rover.ebay.com/rover/0/0/0?mpre ... 2395858783

Thanks haha I seem to remember using vice grips with some padding duct taped to the end seemed to work well.

Why would you need the second ones? Getting the pistons out and in wasn’t too much hassle from memory with the first tool?


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[Yakama]

The set of brakes I had were really seized, the first tool wouldn’t even touch them. It took a fair bit of effort even with the second tool. They came in a box of spares I had

[moforockband]

use a small piece of 0000 wire wool, it cleans the grooves really well. Any stubborn stuff can be gently picked out with a flat screwdriver or similar. Just dont scrape the grooves with anything sharp as they are alloy and will score instantly,