Fazer Owners Club - Unofficial
Bikes, Hints'n'Tips => FZS600 Fazer => Topic started by: Mr Juju on 29 October 2017, 12:22:21 pm
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Hi All, Gone to replace rear brake pads and the cylinder won't go back into the pistons. What could I try? Cheers!
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Brake cleaner spray could be your friend, but if it's not budging it really does sound like it's clogged up and needs an overhaul to be honest.
It's not gonna get better, it'll just end up wearing your pads and disc out if it can't release through movement.
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For stuck caliper pistons I use duck oil and a G clamp.
Give it a good clean with duck oil and a rag then gently and slowly clamp back into place, remove clamp and pump piston or about 75% and repeat until smooth and free.
When happy push the piston in and clean with brake cleaner. Finally apply a smear of red rubber grease to the piston.
I have specified duck oil for this as it is safe for use on the seals. Do not use wd40 it will destroy them.
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For stuck caliper pistons I use duck oil and a G clamp.
Give it a good clean with duck oil and a rag then gently and slowly clamp back into place, remove clamp and pump piston or about 75% and repeat until smooth and free.
When happy push the piston in and clean with brake cleaner. Finally apply a smear of red rubber grease to the piston.
I have specified duck oil for this as it is safe for use on the seals. Do not use wd40 it will destroy them.
Any mineral based oil or grease will perish the seal or any other rubber parts, I have heard of guys using Cooper Slip/Ease on their brake Pistons/Pots, again the kiss of death to the seals.
Red Rubber Grease or a Silicon Grease will stand you in good stead, there may be others but Red Rubber grease is always my choice, I used it on the needle bearing on my suspension linkage as well, just because it is waterproof and will not get washed off or slowly dissolved in a wet area link the linkage that take a battering from spray.
https://www.ebay.co.uk/itm/Granville-Red-Rubber-Grease-Lubricant-70g-Brake-Calliper-Piston-Hydraulic-System/401157686201?epid=1075137105&hash=item5d66dc83b9:g:~1IAAOSwRgJXkM3r (https://www.ebay.co.uk/itm/Granville-Red-Rubber-Grease-Lubricant-70g-Brake-Calliper-Piston-Hydraulic-System/401157686201?epid=1075137105&hash=item5d66dc83b9:g:~1IAAOSwRgJXkM3r)
or alternatively this will last a life time
http://www.ebay.co.uk/itm/Granville-0846-500g-Rubber-Grease-Red/112588817758?_trkparms=aid%3D555019%26algo%3DPL.BANDIT%26ao%3D1%26asc%3D20151005190705%26meid%3Db5680e409d3a448c8e7ede0aa091fb93%26pid%3D100506%26rk%3D1%26rkt%3D1%26&_trksid=p2045573.c100506.m3226 (http://www.ebay.co.uk/itm/Granville-0846-500g-Rubber-Grease-Red/112588817758?_trkparms=aid%3D555019%26algo%3DPL.BANDIT%26ao%3D1%26asc%3D20151005190705%26meid%3Db5680e409d3a448c8e7ede0aa091fb93%26pid%3D100506%26rk%3D1%26rkt%3D1%26&_trksid=p2045573.c100506.m3226)
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Before you start pushing the piston back with clamps or other mechanical devices, with the caliper off pump the brakes a bit. Not too much that the piston pops out completely, but enough to push it out a bit more that it would when fitted. This should give you access to better clean up the ridge of crud that is likely causing you problems.
Trying to push it in before cleaning this up is likey to ruin the seals,
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Split the caliper then change the seals. Make sure you clean out the groves, a round wire brass dremmel wheel is ideal these groves will be corroded pushing seals out so the piston sticks.
Don't loose the small oring between two halves. Polish pistons or replace if pitted on surface in contact with seal. Use red rubber grease when fitting seals.
Good as new.
Hope that helps.
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Chances are it's still on the original seals and if pistons are sticking it's pretty certain the seals are buggered. Unless you're pressed for time it's worth doing the job properly.
Use a clamp to hold the less-jammed piston while you use the brake pedal to force the stuck one out.
You might want to buy a piston removal tool to wriggle the other one out.
Alternatively you can split the calliper which does make cleaning easier, though that's another seal to buy.
Strip out the old seals and replace with new (OEM).
The pistons are heavily chromed and often clean up OK. While there may be some pitting, so long as it is outside the area that contacts the seals you won't need to replace.
Duck oil, WD40, GT85 whatever your favourite water displacement fluid is… they're all basically the same stuff i.e petroleum distillates. Stick to brake cleaner or isopropanol and red rubber grease.
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hi all, i bought myself a set of caliper removal pliers (sealy} and i cant praise them enough. i was impressed with the control, moving the pistons in / out and turning to them for cleaning cheers
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I'm going to be Doing this very job in the next few days, cleaning Pistons in situ does improve your brakes but replacing the seals totally transform your brakes ( if the Pistons are scrap replace with new)
I've got new seals ready, new stainless bleed screws and banjo bolts and new ebc HH rated pads ready to go in.
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oops what i meant to say was caliper piston removal pliers, as they grab the piston on the inner surface,
i would be interested to know if pulling the piston out rather than actuating pressure to it would be bad for
the brakes. as i have only cleaned once using these. stainless banjos essential mogs