binding front brakes but no pulsing lever? (CBR600F4-Y)

[TUG]

My front brake feels like its got a warped disc but I'm not getting pulses through the master cylinder, I remember someone saying they had this problem with their CBR600F but can't find it, its really becoming bit of a pain in the arse but I don't want to rip apart my front end to find out it's something simple so thought i'd do the smart thing and ask first.
Any help would be excellent with thanks in advance and karma to dish out.
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Haz ER-5, innit!

[neatbik]

Could be filthy calipers. Whip them off, pull the pads out and see what condition the pistons are in.

[fatpies]

Its just going to be the pistons sticking. You need to take them out (complicated by the opposing calipers) and clean them up.

If you don't fix it THEN you'll get a warped disc as they are on all the time and will heat up fast.
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"It's easy to attack and destroy an act of creation. It's a lot more difficult to perform one"

[TUG]

Cleaning brakes is piss easy, I resort to using engine braking and rear brake to stop anyway so i'll whip out the pistons on friday, i wouldn't of thought this would cause front end judder though would it?

I'm a little rusty on my symptoms so cant remember.
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Haz ER-5, innit!

[MarkJ]

Are the calipers sliding or fixed calipers? My Hornet (with sliding calipers) discs warped and I never got any pulsing through the lever, just a judder at high speed and a feeling of someone using the brakes more/less as the wheel turned at low speed.

[Kickstart]

Hi

What do you mean by it feels like a warped disk but without it pulsing at the lever?

Do you mean that the brakes are juddering? If so firstly thing I would suggest would be checking the steering head bearings as any play there will amplify any juddering.

I have had a problem with some disks that caused juddering due to, for want of a better word, residue of material on one point on the disk (cast iron disk which a pad had stuck to when parked up wet).

All the best

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

[Mrjoolz]

I have the exact same problem on my ZZR600. Had it for a month or so now. purchased new discs and pads, but Paddy and I are planning to clean calipers whilst changing pads and discs this sunday.

I get a tapping noise as I am thinking piston has build of of crap on it and isnt returning as much as it should and therefore pushing pad onto a now warped disc.

Caliper off, pads out, clean pistons with brake cleaner and toothbrush then reseat pads and bolt on caliper... see if it makes a difference. (Dont forget Loctite on caliper bolts)
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Previous Bikes: TZR125, KMX125, RGV250, RD350YPVS, GXSR750H, GSXR600SRAD, R1 (2000), GSXR1000 (K1), ZZR600, CBR1100XX Super Blackbird

Current Bike: Suzuki GSX1300R Hyabusa.....

[Frost]

As already said cleaning the pistons up might help a bit, but to really sort it you'll probably need to get the pistons out completely and inspect the seals. Taking them out and cleaning them and their seats is what really needs doing. Also grease all moving parts like the brake pad pin and caliper float.

[Mrjoolz]

if I take the pistons right out, will it mean having to buy new seals ? reason I ask is that I am planning on doing this on Sunday, and if I need to replace seals, then the local dealers wont be available.

:o(
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Previous Bikes: TZR125, KMX125, RGV250, RD350YPVS, GXSR750H, GSXR600SRAD, R1 (2000), GSXR1000 (K1), ZZR600, CBR1100XX Super Blackbird

Current Bike: Suzuki GSX1300R Hyabusa.....

[Beelzebob]

[Robby]

Before replacing a disc, check for corrosion on the mounting points. I thought I had a warped disc on my old CB500, but there was just loads of corrosion on the mounting points on the wheel.

[SoND]

[SoND]

[Noxious89123]

SoND whilst you might call it pulsing, it *ISN'T* felt through the lever.

My bike does this but is only noticable just before coming to a complete stop. It's down to having areas on the disc where more friction material from the pads has been laid down.

Cleaning the discs makes it go away, but it soon returns within a few miles of riding. I'm using EBC discs and EBC HH pads.

Plan to give the discs a clean up with emery cloth and brake cleaner at some point and fit some new OEM Nissin pads, then bed them in all over again.

It's like the pads grip some parts of the disc more than others.

EDIT: Would also add that I've had this issue with 2 sets of discs, original OEM ones and EBC ones, and also have had brakes stripped and serviced by a garage with new seals. Also have had a new front wheel with the old EBC discs refitted onto. (dented the rim, unrelated). Issue persists.

Only way I have been rid of it is by cleaning the discs. I think it's down to either crappy pads or not bedding them in properly.
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'06 Honda CBR125RW-6 ~ '00 Honda CBR600F-Y ~ '07 Honda CBR600RR-7 ~ Bikeless
'53 Ford Ka 1.3 ~ '03 Vauxhall Astra SRi 1.8 ~ '52 Vauxhall Astra SRi 2.2 ~ '53 Vauxhall Astra GSi

[TUG]

[Noxious89123]

The bobbins on the discs have never been loose, even on the brand new EBC discs!

Surely whether of not they should move is down to if they are fully-floating discs or semo-floating discs. Apparently fully-floating discs are noisy as fuck and rattle. Mine have never done that, even with brand new discs.
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'06 Honda CBR125RW-6 ~ '00 Honda CBR600F-Y ~ '07 Honda CBR600RR-7 ~ Bikeless
'53 Ford Ka 1.3 ~ '03 Vauxhall Astra SRi 1.8 ~ '52 Vauxhall Astra SRi 2.2 ~ '53 Vauxhall Astra GSi

[Robby]

Have both of you taken the disc off and cleaned back any corrosion where it seats? The tiniest bit of scum makes a difference, you should clean back to bright clean metal.

If you've eliminated everything else, and it sounds like you have, then this is probably the cause.

Remember, put stainless steel and alumium alloy together and you can sit back and watch corrosion happen quickly. This is why you don't use stainless bolts on alloy engines.

[TUG]

[Noxious89123]

I think the new wheel was clean when I received it, but couldn't say for sure.

I'll let TUG be the guinea pig to save me needlessly taking out the front wheel
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'06 Honda CBR125RW-6 ~ '00 Honda CBR600F-Y ~ '07 Honda CBR600RR-7 ~ Bikeless
'53 Ford Ka 1.3 ~ '03 Vauxhall Astra SRi 1.8 ~ '52 Vauxhall Astra SRi 2.2 ~ '53 Vauxhall Astra GSi

[TUG]