Supermooser Posted May 12, 2011 Share Posted May 12, 2011 I'm renovating a DT125R and had to replace the rear wheel. Now I have done that I CANNOT GET ANY PRESSURE FROM THE REAR BRAKE AND THE BRAKE DOES NOT OPERATE. The rear brake caliper is fixed to the wheel spindle, so when I removed the wheel I (probably incorrectly), I disconnected the rear brake cable from the caliper so that the caliper could be removed connected to the wheel spindle. I have now read that I have made some errors in the way I removed the wheel and in particular the rear brake caliper. The rear brake cable that I disconnected from the caliper has obviously leaked some brake fluid whilst the wheel was replaced. Now I have replaced the wheel/caliper and reconnected the rear brake cable to the caliper, the rear brake arm swings almost freely with no pressure and does not apply the brake. I have tried to bleed it to remove any air/ but because there is no pressure it does not seem to even pump the brake fluid out of the bleed nipple, although I can hear air being projected from the bleed nipple when i operate the foot lever/brake. Can anyone help me as I am dying to ride it again but not without a rear brake. One additional point - does anyone know why the caliper removal is not included in the instructions for removing the wheel or at all in the Haynes manual. The caliper doesn't even exist in the diagrams of the rear wheel/spindle etc and is not mentioned in removing or replacing the wheel - hence my error Help!!! Link to comment Share on other sites More sharing options...
edw231193 Posted May 26, 2011 Share Posted May 26, 2011 I'm renovating a DT125R and had to replace the rear wheel. Now I have done that I CANNOT GET ANY PRESSURE FROM THE REAR BRAKE AND THE BRAKE DOES NOT OPERATE. The rear brake caliper is fixed to the wheel spindle, so when I removed the wheel I (probably incorrectly), I disconnected the rear brake cable from the caliper so that the caliper could be removed connected to the wheel spindle. I have now read that I have made some errors in the way I removed the wheel and in particular the rear brake caliper. The rear brake cable that I disconnected from the caliper has obviously leaked some brake fluid whilst the wheel was replaced. Now I have replaced the wheel/caliper and reconnected the rear brake cable to the caliper, the rear brake arm swings almost freely with no pressure and does not apply the brake. I have tried to bleed it to remove any air/ but because there is no pressure it does not seem to even pump the brake fluid out of the bleed nipple, although I can hear air being projected from the bleed nipple when i operate the foot lever/brake. Can anyone help me as I am dying to ride it again but not without a rear brake. One additional point - does anyone know why the caliper removal is not included in the instructions for removing the wheel or at all in the Haynes manual. The caliper doesn't even exist in the diagrams of the rear wheel/spindle etc and is not mentioned in removing or replacing the wheel - hence my error Help!!! Hmmmmm this sound like a tricky one, if it is not bleeding then there must be something jammed in the pipes or the lever is broke. I have changed pads on mine before but when i did i never disconnected any pipes, one thing that was very clear why my brake would not work was the fact the the pads were so rusted and impossible to move. What i would do is try to unblock the pipe and look at the condition of your caliper, and lastly when filling with new fluid be sure not to allow any air into the system, this can be avoided by having the nib of the oil conatined fully emersed in your oil resevoir. Let me know how you get on Elliot Link to comment Share on other sites More sharing options...
NEV Posted May 26, 2011 Share Posted May 26, 2011 Hmmmmm this sound like a tricky one, if it is not bleeding then there must be something jammed in the pipes or the lever is broke. I have changed pads on mine before but when i did i never disconnected any pipes, one thing that was very clear why my brake would not work was the fact the the pads were so rusted and impossible to move. What i would do is try to unblock the pipe and look at the condition of your caliper, and lastly when filling with new fluid be sure not to allow any air into the system, this can be avoided by having the nib of the oil conatined fully emersed in your oil resevoir. Let me know how you get on Elliot Try opening the bleed nipple on the caliper just the tiniest of amounts, rather than opening two or 3 turns fully open,, failing that cable tie your lever on to the grips, sometimes the air travels back up to the reservoir. Link to comment Share on other sites More sharing options...
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