Re: Bleeding Disc's

zen cycle <funkmasterxx@hotmail.com> wrote:

On 3/20/2025 4:53 PM, AMuzi wrote:

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.
 

 
We called that "physics" where I come from.
 

I’d suggest using a bike shop at this point! I have to as my brain just
doesn’t work the way it used to.

And frankly bleeding discs is every few years.

Roger Merriman