Cherokee 180 soft brake - causes?

On Fri, 24 Feb 2006 22:51:31 GMT, wrote:

On Fri, 24 Feb 2006 16:52:10 GMT, Nathan Young
wrote:

snip

Question: Are the symptoms I describe part of normal brake wear? Ie
the pad wears down, and now the piston has to extend further? I don't
understand why this would cause softness though...

When the master cylinders are static, fluid can flow through them to
make up the difference in volume from the pistons extending from
pad/rotor wear.

Once you apply toe pressure, the system closes, trapping the fluid
between the piston/s.

The hand brake cylinder is in series with the toe cylinders. The fluid
flows from the reservoir to the hand cylinder inlet, out of the hand
cylinder outlet to the inlets of the toe cylinders.

Sounds to me like you've got some air trapped in the one side, you are
compressing with the toe cylinder, and also with the hand cylinder
(via the route described above).

Thanks for the info, I appreciate it. Several years ago, when I first
bought the plane, it had air in the brake lines, and myself, my IA and
one of his techs spent quite a while chasing the bubbles away.

I am not looking forward to that experience again...