Looking after front calipers

[Glenben92]

Is there anything I can do to stop the front brakes from jamming up so quickly in winter / wet weather. Whenever I come in, whether I hose the bike down or not and whether I wipe the discs down or not, the next morning there's always a small film of rust over the disc and over time the pistons and sliders need pulling apart, cleaning and greasing before reassembly. I understand that it's a common problem but what can I do about it?
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57 Huoniao HN125-8 - , 97 Kawasaki GPZ500S -
99 Yamaha FZS 600 -
Mod 2 Passed - 01/10/2010

[shippy]

[mysterious_rider]

[Robby]

Discs rusting over is normal and nothing to worry about.

Calipers binding is likely to be down to corrosion behind the seal - I assume you've been stripping and cleaning them, maybe popping out the pistons and cleaning them. You also need to (once every 10 years) remove the seal in the caliper and scrape out the corrosion behind it. You should replace the seal afterwards, but I normally don't. Be careful removing it.

[janner_10]

If you have just got the bike and have this problem, I would be inclined to arm yourself with a new set of seals and give the calipers a bit of a rebuild and fit the new seals.

This should also give you chance to have a peak at the pistons thoroughly and the space behind.

I did it after winter, and whilst its a good mornings work, its nice to know all is well down there!

I paid about £25 for the seals and various bits.
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Yamaha FZS600 (Now gone to heaven) > CBR600F4i (SOLD) > '99 YZF-R1

[numpty2]

Yes this seems to happen to all my bikes eventually. It is a consequence of bike age & riding through multiple British winters.

Pick a nice day and spend it stripping the whole calliper right down.
If the bike is a keeper, I'd simply replace everything - pistons, seals, pins etc. This should then see you right for the next few years.

People seem to then use a variety of greases on rebuild, which should help to minimise subsequent sticking. I'm sure others will be able to recommend appropriate stuff.

[Kickstart]

Hi

Disk rust isn't unusual but depends on the material the disks are made from. Cast iron is a good material for brake disks but rusts like crazy hence is virtually never used on Japanese bikes. Sometimes used for aftermarket disks though. Other materials rust to a lessor extent.

However, where are the calipers sticking? If the brake is binding on hard, and then frees suddenly then it could be the disk and the pads binding together. Reasonably common with cast iron disks (the Bimota is a pig for it).

If the calipers themselves are sticking (rather than the pads sticking to the disk) then as above, whip the caliper off, pump the pistons out, take the seals out and clean behind the seals. The reasemble and bleed. Depends on the bike how often this needs doing (Charlottes Triumph needs this doing very regularly while the Bimota is over 20 years old and I don't think it has ever been done).

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Glenben92]

well the surface rust on the disc was the main thing, i used to get it on the GPZ all the time. The GPZ was the one with the seizing problem but that's because the caliper is pretty much shot. It was just walking out thismorning to see surface rust on the disc of the fazer that made me think is there anything i can do to preserve a good disc and calipers. fazers brakes havent stuck or anything, i'm not expecting it because there aren't massive holes in the rubbers this time lol. a few reviews mention fazer calipers in winter though.
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57 Huoniao HN125-8 - , 97 Kawasaki GPZ500S -
99 Yamaha FZS 600 -
Mod 2 Passed - 01/10/2010

[janner_10]

I find the back suffers more than the front due to its position - but both sets are very easy to dismantle and rebuild. I just give mine a bit of a spray and a clean with a toothbrush monthly since the rebuild.

Other than that, awesome brakes.

I don't have rusty discs though ever, but they are the yam genuine ones, whether that makes a difference or no.
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Yamaha FZS600 (Now gone to heaven) > CBR600F4i (SOLD) > '99 YZF-R1

[Glenben92]

[neil.]

Preventative maintenance is a good idea with these. I give mine a going over at every service interval (2'500 miles). By that, I mean;

Take the calliper off the disc.

Carefully pump out the pistons about halfway, making sure the fluid level doesn't drop too low in the master cylinder.

Attack the lot with brake cleaner and a toothbrush until it's clean.

Do the same with the sliders and pad pin.

Grease the sliders and pistons with red rubber grease (don't use much on the pistons, you only want a thin smearing). Give the pad pin a smearing of copper grease, especially on the threads.

Roughen up the pads with some wet and dry paper and give them a going over with brake cleaner.

Smear copper grease on the backs of the pads - not the braking surfaces!.

Put it all back together.

After riding all year round and accumulating 15'000 miles on the current bike, the front wheel still turns freely after applying the brake and the pistons can still be pushed back in by thumb pressure alone.
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CBT February 2008 | A2 June 2008 | Yamaha YBR125 (written off) | Honda CBF125 (current)

[Fizzer Thou]

A friend got caught in the rain a while back and when the bike was next ridden the pads were stuck to the discs.I put this down to the high metallic content of the pads.Once the brakes had been applied after riding off the braking area of the disc was clean again and the wheel rotated freely.
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