Shimano Ultegra hydaulic brakes, levers excessive travel

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flat tyre
Posts: 565
Joined: 18 Jul 2008, 1:01pm

Shimano Ultegra hydaulic brakes, levers excessive travel

Post by flat tyre »

I've put ultegra hydraulic brakes on my latest bike. I've got a problem with the levers having excessive travel, right up to the handle bars before effective braking occurs. I've tried adjusting the free travel according to the Shimano manual but this makes little difference. I've also bled the brakes since installing them several times to make sure that the problem isn't air in the system, I don't think it is as the brakes bite firmly and both levers have the same feel. All the parts I've used (cables, fittings etc) are the Shimano items supplied with the groupset.
One action that seems to cure the problem is to take the wheel off and then squeeze the brake a few times so that the pads meet together. After this the brake lever is good and feels like it should do with only a little travel before biting. However, this only lasts a few rides before it is back to the old problem with excessive travel.
I'm just wondering if this is normal with Ultegra brakes of if there's something I've overlooked with the set up.
DevonDamo
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Joined: 24 May 2011, 1:42am

Re: Shimano Ultegra hydaulic brakes, levers excessive travel

Post by DevonDamo »

flat tyre wrote: 24 Oct 2021, 10:50amI'm just wondering if this is normal with Ultegra brakes of if there's something I've overlooked with the set up.
How confident are you that you've bled all the air out? Sometimes, bleeding brakes doesn't work unless you take drastic measures. In my case, this has meant ensuring the cable run is completely vertical (which involves removing the calipers to allow them to hang down, and - for the back brake - holding the bike vertically in a stand) and then bleeding from the bottom up, injecting the fluid into the caliper and sucking the excess out from the handlebar reservoir. Add to this copious finger-flicking of the cable to dislodge any sneaky bubbles and a prolonged lever-flicking session at the end, whilst angling the reservoir in all directions to get any hidden bubbles out of the master cylinder. It's amazing how much air manages to stay resolutely trapped in the system despite all the above, but a methodical, perfectionist approach works in the end.

The only other experience I've had that matches yours was when a caliper needed replacing. It had repeatedly gone back to being spongy a few rides after bleeding, and only a new caliper resolved it. This was on a mountain bike, and I suspect the problem was a build up of contamination preventing the piston from always self-adjusting to the correct position relative to the seal. I dismantled the old caliper and cleaned the seal and piston, and will attempt to use it as a replacement if the new one ever plays up.
flat tyre
Posts: 565
Joined: 18 Jul 2008, 1:01pm

Re: Shimano Ultegra hydaulic brakes, levers excessive travel

Post by flat tyre »

Thanks for the bleeding tips (if you'll pardon the expression!). I had another go and followed your advice including detaching the rear caliper etc. The brakes seem to be be much better now, hopefully they will stay that way.
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Redvee
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Joined: 8 Mar 2010, 8:58pm

Re: Shimano Ultegra hydaulic brakes, levers excessive travel

Post by Redvee »

After bleeding go for a ride then do another quick bleed to get the last bit of air out of the system. I installed hydraulic brakes on my bike and they felt good and firm but after a ride I did a 2nd bleed and the number of air bubbles that appeared in the bleed funnel was quite high.
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