Re: Bleeding Disc's

On 3/20/2025 2:46 PM, cyclintom wrote:

I can't say what's going on. The fact that you had to bleed the rear brakes backwards but I cured the front brakes which you would think wouldn't be a problem since it is all vertical hoses was amazing. Bleeding that brake from top to bottom releases a lot of air bubbles after which the disk levers were hard and with about a half way pull to lock.
 The levers with the bleeding cap off appeared top be full of liquid so the levers were full and it couldn't be air trapped somewhere in the levers.
  but installing a funnel and filling it half way and using the syring on the bottom pulled a great deal of air out of the system.
 So while the Shimano instructions and most of the videos showed bottom to top, bleeding trom top to bottom as one video, made by a woman mechanic seems to be the only way to get the brake properly bled.

Right you can't purge the air unless fluid flow is bottom to top. Exactly the opposite of autos.
Air collects in the various caliper voids and doesn't readily reach the line when you are pushing fluid. Remove the caliper from its mount and tap it with something while you flush the line.
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971