Dura Ace BR7800 rear brake QR problem - Sorted

Gerryattrick

A friend has just bought a Dura Ace equipped bike second hand that she wants me to service. There's a problem with the QR on the rear brake in that the bit that grips the cable moves with the QR instead of always staying in the vertical position. The previous owner obviously ran it with the QR fully opened and the cable tightened to correctly position the brakes. The front is fine and looks to be exactly the same mechanism (as confirmed in the Shimano tech doc). It looks as if it should come apart easily with a bit of prising, but doesn't, and as it's someone else's bike I'm wary of putting too much force on it in case I bugger something up.

Any ideas please :idea: :idea:

Sussed out

I have exactly the same issue, I got a set from a friend who I don't think ever opened the quick release so it's really sticky. I tried taking the little screw out and prised it but it got to a certain extent then wouldn't budge further.

Gerryattrick

It seems as if it should just slide out but I put a fair bit of pressure on it and it doesn't move. I may have to give up and get my friend to take it to a bike dealers, which will probably cost a fair bit of money.

I hate not being able to sort something that should be simple. :twisted:

Gerryattrick

Finally sorted it. It was stuck, either with grit or corrosion. I soaked it first in Plus Gas and then sprayed it with GT85. Then I fixed the QR lever in position with a strong cable tie to stop it moving. Next I used a hex spanner in the cable securing nut to provide leverage and started using increasing force in both directions until I had some movement then continued working at it. After a couple of minutes it became fully loose and now works perfectly.

I didn't need to take it apart thank goodness as I understand there's a very fiddly, small spring and bearing inside it that's a swine to re-assemble.

Hope it works for you.