Bleeding Shimano Dura-ace groupset

[wojpolwoj]

I installed new hoses in my Dura-ace 9170 groupset and bled a whole system. All works great until I tighten up the lever clamp to the recommended 6-7 NM, and then the levers get stiff, and the levers do not go back to the beginning without manual help. Do you have any ideas on what is going on?

[mike]

you may be bending the hose at an extreme angle when tightening lever to your bars. you may have to cut some of the hose to make a perfect fit and no bends

[mikehhhhhhh]

you may be bending the hose at an extreme angle when tightening lever to your bars. you may have to cut some of the hose to make a perfect fit and no bends

This, levers not returning is classic kinked hose behaviour

[wojpolwoj]

Thank you for your advice. I will investigate this but still can't understand how tightening up a lever clamp may cause something like this.

[wojpolwoj]

I've just found this movie: https://www.youtube.com/watch?v=U2g-t4Msl0w
It exactly portrays my problem. Shimano recommends tightening the clamp to 6-7NM. Is it ok to use 5NM because then all is good?

[Mr.Gib]

Yes, 5nm is fine - more then enough. 3 - 4nm might be all that is needed. Experiment to test that the lever won't move from normal riding forces. Don't forget any sprinting you might do on the hoods.

Love my 9170 but what a joke that the design is susceptible to this problem.

[pushpush]

I try to tighten everything on my bars to the minimum torque that keeps them from moving. An old mtb habit to minimize damage when crashing into things. Things that don't move at all tend to break.

[svendsvin]

Somewhere on the internet, a shimano rep is cited for, that it is connected to undersized bars. The bars diameter are below 23.8mm? The lever housing distorts from the clamping force and the master cylinder binds.

Maybe try thickening the bars under the clamps with something...

[wojpolwoj]

Somewhere on the internet, a shimano rep is cited for, that it is connected to undersized bars. The bars diameter are below 23.8mm? The lever housing distorts from the clamping force and the master cylinder binds.

Maybe try thickening the bars under the clamps with something...

I was trying to install a Roval Rapid cockpit in my Tarmac Sl7. I do not think it is undersized. Finally, after much trial and error, I installed levers and torqued them with 6NM. I have a feeling that levers are almost in the sam position like at the beginning but now levers work perfectly. Thank you all for your advice.