Date:         Mon, 23 May 2005 11:40:14 EDT
Reply-To:     THX0001@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         George Goff <THX0001@AOL.COM>
Subject:      Re: Pressure Bleeding the Clutch slave/master
Comments: To: Oxroad@aol.com
Content-Type: text/plain; charset="US-ASCII"

In a message dated 5/23/05 3:07:41 AM, Oxroad@AOL.COM writes:

<< The mini-vac in a suction pump for self brake bleeding and the like which
is pumped by hand. Or does the system need to be pressure bled with a pressure
type pump attacted to the master cylinder reservoir? >>

I've never had a Mini-Vac, but I've used vacuum sources to bleed automotive
hydraulics; I prefer pressure bleeding.  Vacuum bleeding might work well if the
bleeders are the O-ring type.  In my experience, a standard bleeder under
vacuum will suck air through its threads and so it is hard to tell at what point
all the air has been removed from the line.

A pressure bleeder can be hacked together in so many different ways that it
merits no description.  Any reservoir which can safety contain air at as little
as 10 psi will do and any source of compressed air (even a bicycle pump) will
work.  A vacuum bleeder is similar and a running engine is a ready source of
15-20 psi of negative pressure with which to charge an air tank.

On procedure which I have not seen mentioned in these discussions is bench
bleeding the master cylinder.  Bench bleeding the master cylinder can make a big
difference in how easily the system is purged of air, especially with a two
circuit master brake cylinder.

George