You're definitely looking at a hydraulic issue, but it may not be the master
cylinder.  Look at the brake fluid level first.  If that's normal, it may
indeed be the MC, as fluid may be flowing past the piston seals.  My
experience has been that an external leak is more likely the culprit.  Check
for fluid around the front calipers, or remove the rear drums and see how
the slave cylinders are doing.

Regarding DIY, it all depends if you're comfortable with dismantling your
dashboard, if it is the Master.

Another note, from personal experience:  immediately, IMMEDIATELY, wipe up
any drop of brake fluid off of the plastic.  The fluid will silently eat
through your dashboard if left unattended.  That's what it did to mine.

Cecil

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
BJ Feddish
Sent: Monday, May 05, 2008 10:07 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Great gas mileage, crappy breaks.

I went to GGB4 over the past weekend. I was happy that I got 21 MPG round
trip and that included plenty of mountain climbing in 2nd and brake fade on
the way down.

Anyway, 1 mile from my house yesterday I almost rear ended a pickup truck as
my brake pedal went all the way to the floor. Pumping did not help. My pads
and shoes are less than a year old and the system was bled a month ago.  I
left a message at my mechanics to fix this but is this most likely the
master cylinder on it's way out? Should I pick one up at Bus Depot before
bringing the van over? Is this something I can replace myself?

Thanks,
Bryan