Hi all,

TLDR version:

Help please – the rear brake is going soft when the bike is lifted so the front wheel is in the air.

Longer version:

I've had to repair a rear brake, which was caused by a snapped line at the exit of the reservoir. All has largely gone well, except I noticed that it loses the rear brake when it's tipped up with the front wheel in the air i.e. to hang vertically on a wall.

My process when I repaired the line:

  • Used a funnel on top of the reservoir (ensuring it always had enough oil), gravity feed through the rear bleed screw to clear the line & change the oil.
  • Fitted the rear bleed screw
  • Tapped the lines while pumping the brake handle, some bubbles came up the funnel
  • Eventually removed the funnel and refitted the reservoir screw
  • Test run, it worked well
  • Then when lifting vertically up stairs I noticed the rear handle went soft, however, it would mostly come back when it was flat on the ground again
  • Thinking there was still air in the line, this time I used the two syringe method, seemed to get some more bubbles coming up, though I can't be sure I didn't introduce them when fitting the syringes..
  • Back and forth between the syringes 5 times
  • Including 2 times after no more bubbles to be seen

But it's still going soft the front wheel is in the air, recovering when back down.

Am I doing something obviously wrong here?

by rslegacy86

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