Disc Brakes stucked

m o b

Speeding Up
Jun 22, 2008
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Bremen
cyclitis.wordpress.com
#1
I am a roadie, all my bikes are road bikes of various materials but I own one Cannondale Bad Boy Ultra 2005 model:

http://cyclitis.wordpress.com/2012/04/02/bad-boy-der-bose-bub-eugen/

Nowadays I only use it during winter time. I store it in the garage between April and November; then I clean it and ride through the snow and then I clean and lubricate it and store it again for the next year.

Unfortunately bad boy is equipped with hydraulic disc brakes of which I have no clue whatsoever how to maintain and repair them.

Now the brake pads constantly rub on the rotor. So I removed the pads, cleaned them, also cleaned the brake saddle with brake cleaner and WD40.
Then I took a wedge and moved the brake pads away from the rotor, then reinstalled the wheel.

When I brake first nothing happens becuase the pads are too far away from the rotor first. They move in and after braking two or three times, they touch the rotor and braking starts. But they don't move back again, basically rubing again at the rotor. So I deinstalled the wheel, moved the brake pads away from the rotor with a wedge again and again and again.

Any idea what the cause could be and how to repair this? Thanks for your help. Disc brake type is Hayes, no idea about which model.
 

kiwisimon

Maximum Pace
Dec 14, 2006
2,681
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Japan
#2
I am a roadie, all my bikes are road bikes of various materials but I own one Cannondale Bad Boy Ultra 2005 model:

http://cyclitis.wordpress.com/2012/04/02/bad-boy-der-bose-bub-eugen/

Nowadays I only use it during winter time. I store it in the garage between April and November; then I clean it and ride through the snow and then I clean and lubricate it and store it again for the next year.

Unfortunately bad boy is equipped with hydraulic disc brakes of which I have no clue whatsoever how to maintain and repair them.

Now the brake pads constantly rub on the rotor. So I removed the pads, cleaned them, also cleaned the brake saddle with brake cleaner and WD40.
Then I took a wedge and moved the brake pads away from the rotor, then reinstalled the wheel.

When I brake first nothing happens becuase the pads are too far away from the rotor first. They move in and after braking two or three times, they touch the rotor and braking starts. But they don't move back again, basically rubing again at the rotor. So I deinstalled the wheel, moved the brake pads away from the rotor with a wedge again and again and again.

Any idea what the cause could be and how to repair this? Thanks for your help. Disc brake type is Hayes, no idea about which model.
You need to bleed the brakes, sounds like you have air in the system.
Do a search on you tube for bleeding hayes brakes and you'll find the method. Easier to pay a shop to do it but once you know how it's not that difficult.
 

StuInTokyo

Maximum Pace
Dec 3, 2010
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#3
You need to bleed the brakes, sounds like you have air in the system.
Do a search on you tube for bleeding hayes brakes and you'll find the method. Easier to pay a shop to do it but once you know how it's not that difficult.
.... and the caliper could have been bumped moved etc and might need to be realigned, basically you loosen two bolts, and then apply the brakes, and tighter the bolts, again, look it up on the net, easy to do.

Cheers!
 

AlanW

Maximum Pace
Jan 30, 2007
1,214
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Tokyo
#4
Sounds like you have sticky or stuck pistons.

In the photos your brakes look like Hayes HFX-9 or some variant thereof. My experience of these brakes has been bad, primarily because of the rubbing issue you mentioned. It's tough to get them running quietly and drag-free for any length of time.

The sticky pistons are probably due to degraded seals, given your bike is from 2005 and has been sitting for long period. The good news is that you can get new seals which will probably fix the problem. The bad news is that changing seals is fairly complicated and messy, as the hydraulic fluid used by Hayes is toxic and corrosive enough to strip paint.

Before you try a seal change, check first that the pads are not excessively worn. When the amount of pad material left is thin, sometimes the pistons don't retract properly. You can buy new Hayes pads anywhere.
Secondly, try pushing the pistons back in and out a few more times. They may free up. Be cafeful not to pop the piston out.
Third, make sure the caliper is exactly centred across the rotor. I mean exactly.
Fourth, stop using WD40 near your brakes! WD40 has mineral oils that will attack the seal material used in a system like Hayes that uses DOT brake fluid.
Fifth, you could try a bleed, but I don't think that's the problem. You will need a bleed kit.
Sixth, for the time and difficulty of a seal change on a seven year old brake, I'd think very seriously about ditching the Hayes and getting a new Shimano XT, SLX or something like that. They are much more powerful, easier to control (less on/off than the Hayes) and lighter too. Rose bikes in Germany often have good deals.
Good luck.
AW.

Hayes service instructions here:
http://www.hayesdiscbrake.com/support/heritage-products/hydraulic-disc-brakes/hfx-9-xc/

Caliper seal and piston set here:
http://www.chainreactioncycles.com/Models.aspx?ModelID=20169
 

m o b

Speeding Up
Jun 22, 2008
341
23
38
Bremen
cyclitis.wordpress.com
#5
Wiser

Finally I found the time and also the Hayes bleeding kit to visit my MTB friend and dics brake specialist Jörg. As I couldn't get any sealings for my Hayes Nine brakes, we started with bleeding and other manual adjustements, including replacing the brake pads.

This worked quite well for the rear brake and the pads started to move again in and out. However, the front brake is a different issue.

Anyway, thanks a lot for all the good advise, in particular the one from Alan was very helpful. I hope I will find some Hayes sealings under the Christmas tree and then replace them in due time.