I don't know how to diagnose my brake problem.  I changed master
cylinders and bled the brakes already.  Anyway the basic symptom is if I
pump them up and push hard the brakes hold pressure.  If I ease off on
the pressure the slowly go to the floor.  Sometimes if I quickly push
the brake pedal it goes to the floor, but a quick pump will make it hold
the pressure.  There are more symptoms but that seems to be the main
one. I don't see any evidence of leaking around the wheel cylinders.
Now fact is I substituted an old master cylinder I had lying around from
parting out van a few years ago. The symptoms from the replacement MC
are more or less the same as with the one I replaced, except the one I
replaced wouldn't hold pressure at all.
Any clues or tutorials from the wise members of this group?

1980 Aircooled Westfalia

John Jensen
johnjensen@johnjensenartist.com
http://www.johnjensenartist.com
bluesbug@verizon.net