Date: 16-06-19  Time: 14:10 PM

Author Topic: New technique? Cleaning brake pistons.  (Read 1756 times)

roxburd

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New technique? Cleaning brake pistons.
« on: 22 October 2018, 10:57:17 PM »
I've gotta share this coz I'm dead chuffed with how well it works!! Maybe it's well-known already but I'd never heard of it so here goes.


I was cleaning up my front brake calipers coz the right-hand one had started to drag a bit. Haynes has its usual text - push the pistons out a little and clean the edges up so you don't push any crap back under the seal when you push the pistons back inside the caliper. But while you can get to most of the piston edges, on some parts the clearance between the side of the piston and the caliper body is minute - maybe less than a millimeter. My brush sure wouldn't go in there! And there was plenty of crap that needed shifting. I couldn't rotate the pistons either. The technique I used was this:


Get some thin material (mine was an old shirt). Tear off a strip about 5mm wide. Use brake & clutch cleaning fluid. Thread the strip of material into the gap and work it back-and-forth round the piston. That's it - works a treat. Cleaned up the piston and the caliper body around it. Pistons pushed back into the caliper a treat. Lovely jubbly.


So like I said, maybe everyone does this already but hey, if not, give it a go next time.

coffee

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Re: New technique? Cleaning brake pistons.
« Reply #1 on: 22 October 2018, 11:41:53 PM »
Defo try that next time ;)
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stevierst

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Re: New technique? Cleaning brake pistons.
« Reply #2 on: 23 October 2018, 08:47:20 AM »
The simple ones are normally the best, I’ll give that one a go next time it’s brakes service time 👍
Stop polishing it and ride the bloody thing!!

robbo

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Re: New technique? Cleaning brake pistons.
« Reply #3 on: 23 October 2018, 09:33:41 AM »
A useful tool if you maintain your own brakes, is a set of Sealey VS1806 Brake Piston Removal Pliers, cheapest I've seen is £12.50 from Tools4Trade. These would allow you to turn the piston during maintenance/cleaning etc, so the entire leading edge surface can be visually checked.

roxburd

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Re: New technique? Cleaning brake pistons.
« Reply #4 on: 23 October 2018, 06:48:16 PM »
A useful tool if you maintain your own brakes, is a set of Sealey VS1806 Brake Piston Removal Pliers, cheapest I've seen is £12.50 from Tools4Trade. These would allow you to turn the piston during maintenance/cleaning etc, so the entire leading edge surface can be visually checked.


On order! Cheers robbo


I'll turn the pistons to clean them and use the rag-thread technique to clean all the crap out of the gap between the piston and the caliper. Job's a good 'un!

stevierst

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Re: New technique? Cleaning brake pistons.
« Reply #5 on: 24 October 2018, 01:06:31 PM »
Just done my calipers using the rag technique, and it did the trick perfectly 👍


Get it in the top tips as a sticky!
Stop polishing it and ride the bloody thing!!

roxburd

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Re: New technique? Cleaning brake pistons.
« Reply #6 on: 24 October 2018, 01:38:13 PM »
Just done my calipers using the rag technique, and it did the trick perfectly 👍


Get it in the top tips as a sticky!



Excellent - glad you like it ;-)


I'm happy to do a proper write-up... but don't know where to put it... or how to make it sticky - is that an admin-only thing?


The forum could do with a non-model-specific section coz stuff like this applies to all Fazers (and all bikes), not just the 1000.

roxburd

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Re: New technique? Cleaning brake pistons.
« Reply #7 on: 27 October 2018, 03:25:36 PM »
So the Sealy piston removal pliers arrived yesterday and I did my right-hand caliper today. I ended up using the rag-strip technique to clean the pistons all round (gave up using a brush as the rag worked better all-round), then pushed the pistons outs a bit to get to the strips that were hidden inside the caliper but outside of the seals, if you see what I mean. I then buffed up the bits of the pistons that I could see and then used to pliers to turn them round to buff up the bits of the pistons that had been hidden in the small-clearance section. Happy with that - I could see the pistons were in good condition and shiny-clean all round before I pushed them back in.


Cheers robbo - top bit of kit.
« Last Edit: 28 October 2018, 06:32:02 PM by roxburd »

roxburd

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Re: New technique? Cleaning brake pistons.
« Reply #8 on: 28 October 2018, 06:43:14 PM »
I *was* happy with the job... until I tried spinning the front wheel and found that with a good heave it only manages one rotation. I can also hear slight rubbing. Without the calipers the front spins freely so the bearings are fine. The discs don't get massively hot but still, it's not right.


Is it worth lubricating the pistons as it advises in the Haynes manual (silicone grease)? Would that make any difference? Or, as I suspect, is it going to be crap built up behind the seals causing the seals to grip the pistons? Or the seals themselves swelling for some reason and gripping the pistons? Either way, that means a proper overhaul. Bugger.


Anything I should be aware of doing a full overhaul? What's the best way to clean out the seal recesses given the difficulty in accessing them? In the past I've found muck in there that needs cleaning out.

agricola

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Re: New technique? Cleaning brake pistons.
« Reply #9 on: 28 October 2018, 07:37:12 PM »
Lid off the master cylinder, then try pushing them in a little more. It could be that one of the pistons has crabbed, so they might need to be pumped out a little again, checked for squarness to the bores, then eased back in again. Failing that, it might be that you need to pull them out for seal replacement etc. To clean the crap out of the seal locations, I use a small pick tool. There are normally three in a set, one right angled, one oblique, and a straight one. Soak the crap first with something like penetrating fluid to loosen it up. Dont scratch the bores

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Re: New technique? Cleaning brake pistons.
« Reply #10 on: 28 October 2018, 07:55:48 PM »
Lid off the master cylinder, then try pushing them in a little more. It could be that one of the pistons has crabbed, so they might need to be pumped out a little again, checked for squarness to the bores, then eased back in again. Failing that, it might be that you need to pull them out for seal replacement etc. To clean the crap out of the seal locations, I use a small pick tool. There are normally three in a set, one right angled, one oblique, and a straight one. Soak the crap first with something like penetrating fluid to loosen it up. Dont scratch the bores


Cheers dude

ogri48

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Re: New technique? Cleaning brake pistons.
« Reply #11 on: 28 October 2018, 08:08:56 PM »
you guys probably know this, but if you use a vacuum pump to pull the fluid out when you've changed lines or just bleeding( I do), take the bleed nipple out and wind a bit of plumbers ptfe tape around it, then screw it back in but not fully. nip it up when your done, and take off any ptfe excess with a scalpel or Stanley blade if it offends your eyes lol.. stops air getting pulled in around the bleed nipple threads. ;)

darrsi

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Re: New technique? Cleaning brake pistons.
« Reply #12 on: 09 June 2019, 10:56:31 AM »
I *was* happy with the job... until I tried spinning the front wheel and found that with a good heave it only manages one rotation. I can also hear slight rubbing. Without the calipers the front spins freely so the bearings are fine. The discs don't get massively hot but still, it's not right.


Is it worth lubricating the pistons as it advises in the Haynes manual (silicone grease)? Would that make any difference? Or, as I suspect, is it going to be crap built up behind the seals causing the seals to grip the pistons? Or the seals themselves swelling for some reason and gripping the pistons? Either way, that means a proper overhaul. Bugger.


Anything I should be aware of doing a full overhaul? What's the best way to clean out the seal recesses given the difficulty in accessing them? In the past I've found muck in there that needs cleaning out.


Don't use anything other than Red Rubber Grease on brake pistons. You can use it to keep the rubber seals in place, and aid the refitting of the pots, and it will prolong the life of the rubber.
Then smear it on the exposed area of the pots before pushing them back in so that the pads can be placed.
I service mine just before winter kicks in and then around April when it warms up again, and it keeps them functioning perfectly all year round.
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roxburd

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Re: New technique? Cleaning brake pistons.
« Reply #13 on: 09 June 2019, 04:39:06 PM »
Don't use anything other than Red Rubber Grease on brake pistons. You can use it to keep the rubber seals in place, and aid the refitting of the pots, and it will prolong the life of the rubber.
Then smear it on the exposed area of the pots before pushing them back in so that the pads can be placed.
I service mine just before winter kicks in and then around April when it warms up again, and it keeps them functioning perfectly all year round.


Cheers dude, good tips!