Troubleshooting binding brakes

[pooneej]

New build. 0 miles on anything. Just noticed today as I was going to ride it for the first time for lunch break. Rear brake squeeze felt weird. As in there was some play in it. I then noticed that the caliper wasnt releasing so was causing that play in the lever.

Messed with the open close and adjusted the cable a little bit but was tight on time since it's my lunch break so I took another bike. Came back little while ago and it's not binding anymore. I don't get it. But I suspect it'll probably be back.

There were no real adjustment or installation instructions that came with the brakeset so I'm not sure if spring tension can be adjusted? Or levers? Or is it the actual cable? WHere to start with something like this (when it happens again).

-- DA9100 brakeset. retail box. only instructions were the open close lever.

thanks

[dave thompson]

First you have to determine if the brake itself is binding or if it’s somewhere upstream in the cable or lever. Disconnect the cable from the caliper to see if the caliper is operating properly. I suspect something in the cabling. Also check to see the head of the cable is seating correctly in the lever.

[dddd]

Shimano has now for many years stopped putting instructions in their parts packaging.
Instructions (ostensibly for service professionals) is available online.

Perhaps in this case a cable housing end was not seated somewhere, but has since slipped into place. Did you note any decrease in cable tension adjustment after first noticing this binding?
I very much doubt that the caliper itself was binding, almost surely it was the cabling.

So, if it recurs, first thing I would do is detach the cable from the caliper and check for caliper friction/binding by hand.

[pooneej]

One thing I did do and forgot to mention was that I did squeeze the calipers and they didnt seem to be the cause of the binding. I just thought maybe when tension on it, there is some spring adjustment to make it stronger to return to position?

Next time it happens I'll undo the cable from the caliper itself and go upstream. thanks!