Rock hard brake pedal and poor brake release

["Warren R Anderson" <wranderson@xxxx>]

Good morning,
About everything has been mentioned that can lead to the above. The push rod
and bleed hole in the master cylinder are particularly good items to check.
Brake hoses should be real fresh and changed anyway if going to DOT 5 fluid.
Although replacing brake return springs can be a problem due to availability
of proper new parts this is a good idea in principle and cheap.

Have seen a lot of apply/release problems when backing plates are not
restored properly where shoes rest; squeak, grab, noise, drag. Welding up
worn areas and grinding works to restore these important supposed to be flat
surfaces.

Gummed up wheel cylinders are always a possibility and especially where the
vehicle sees only seasonal or intermittant use cycles.

Had one very revolting experience with a sleeved master cylinder done by a
very prominent supplier. The builder just forgot to drill through the new
sleevefor the bleed port so the brakes would not release occassionally.
Found this after tracing non release problem back to master by progressively
breaking brake lines from farthest brake cylinder back to master.

Had a Corvette come in with a very new but wrong master cylinder once that
would not release properly. The right cylinder was far more expensive so
possibly why someone tried what was the wrong, cheaper part.

Years ago I quit trying to rebuild any master cylinder that is intended to
run on the street. Many reasons, TNTL.

Anyway, I have seen poor brake release from all of the above and do not see
any one any more possible than any other.

Warren Anderson
Sedona,AZ