105 5700 brake lever loose

louman999
louman999 Posts: 90
edited July 2016 in Workshop
When ever I go to apply pressure to my rear brake lever it's very loose. I can press it with one finger but it won't apply the brake. To apply the brake I have to pull the lever even further and it's like normal. Does a screw or something need tightening up???

Comments

  • keef66
    keef66 Posts: 13,123
    Sounds like there's drag in the cable somewhere. Undo the clamp bolt at the caliper and operate the lever while pulling on the inner wire to see how easily it is sliding through the outers. Clean and lubricate to see if it improves.

    Also while the wire is disconnected, squeeze the caliper to see if it's moving freely and there's adequate spring tension.
  • pilot_pete
    pilot_pete Posts: 2,120
    Sounds more like slack in the cable. Look on the Shimano website and get the installation instructions for your brake/ levers, or alternatively search the Park Tools website for how to set up caliper brakes. There are hundreds of videos online that will show you how to do this.

    Basically you need to loosen off the cable clamp at the caliper, pull the cable taught with hands or pliers and clamp the cable again so there is no slack. If you wind the adjuster in before doing this you can then fine tune the outer cable length by winding the adjuster out to bring the pads closer to the rim. This will set where on the lever pull your pads contact the rim and thus the 'feel'.

    You may need to squeeze the caliper together by hand before clamping the cable if the pads sit a long way off the rim under their return spring pressure. Just be sure you pull the cable taught before clamping it to remove excess play which is your 'I can press it with one finger but it won't apply the brake', I.e. The pads are so far from the rim to start with that the lever has to pull up all the slack before they touch the rim, hence you loose all that lever throw before the brakes are applied. I am guessing the lever arm then contacts the bars without full braking effect?

    PP
  • keef66
    keef66 Posts: 13,123
    If he's got slack in the cable his blocks will be so far from the rim he'll have no braking at all before the lever hits the bars. He says it's initially loose then normal.

Categories