Once the clutch driver (master) cylinder is dry it can be difficult to get
it to bleed. Simply pumping will not work. A pressure or vacuum  bleeder or
helps a lot. Otherwise, fill and wait with the bleeder open and allow time
for fluid to flow down into the cylinder. You will need a helper. Push the
pedal down, then close the bleeder, then release the pedal.  Pedal up, open
bleeder, push pedal down again, close bleeder, repeat until you get fluid
out. Sometimes the piston in the driver gets stuck down at which point some
other action or replacement will be needed.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
David White
Sent: Saturday, July 07, 2012 12:45 AM
To: vanagon@GERRY.VANAGON.COM
Subject: the science behind the clutch

84 westie. was an automatic but I put in all the manual stuff a few years
back. I skimped and put a flexible plastic line between the master cylinder
and through the body where, underneath, I go back to steel, flared lines to
the slave cylinder. The other day I blew plastic line. It had appeared to
blow where the plastic line is connected to the barbed fittings on both ends
and I assumed the c-clamps had chewed through the plastic. However now I
can't bleed the system (after I installed a steel line replacing the plastic
line). I take the bleed screw completely out of the slave cylinder and pump
the pedal and nothing comes out. I understand this is not the way to bleed
the system but I assumed that I would get some "spit" of brake fluid after
pumping forever. This makes me think that the cylinder in the slave isn't
moving and the plastic line blew because of increased pressure? Any way to
test this before I spend the bread on both a master and slave cylinder?