[T3] bleeding brakes question

[Jeremy Menzies]

I like the upward curving tube method and if I remember correctly, the illustration in the Bentley has the same configuration.   When I bled mine a couple weeks ago after replacing the rubber lines, I noticed the bubbles creeping back towards the bleed valve but having a helper, I was able to prevent them from going back in.
On a related but different note, I wondered about something a friend told me to be careful about when bleeding the VW brakes.  He said that when bleeding by the 'pump method', the person pushing the pedal down shouldn't go all the way down but only like 3/4 or so.  His reasoning was that when the brakes haven't been worked on in a while (as mine hadn't), there is corrosion that build up on the portion of the piston inside the master cylinder that doesn't move a whole lot during normal, less than full stroke braking.  He was saying that what can happen is that when you go to the floor w/no pressure, it'll push this corroded portion beyond it's normal range of travel and either damage the seals inside the MC, get stuck in the extended position or crud things up as the corrosion is scraped off.  Or something along those lines.  Result being: need to rebuild the MC.
Of course when I bled them I didn't know this so we went to the floor with it.  Now, I noticed that my pedal travels farther than before the bleeding and generally feels softer and I've been wondering if his tale could be a part of it (and a little worried I may have messed up the MC).  I did change the old fluid w/fresh when I bled but I adjusted the rear stars tighter so I expected them to feel harder.  
Any thoughts on this?  The guy did a ton of restoration work on a '76 Bay window he had and pretty much does all his own work on his current Vanagon and New Beetle, so I typically trust his experiences.
-Jeremy

> Date: Tue, 2 Aug 2011 10:34:50 -0500
> From: dhbadeer at gmail.com
> To: type3 at vwtype3.org
> Subject: Re: [T3] bleeding brakes question
> 
> So true.  I read somewhere to use a little grease around the bleeder threads
> to prevent this problem, which I've done.
> 
> On Tue, Aug 2, 2011 at 10:11 AM, Dave Hall <dave at hallvw.clara.co.uk> wrote:
> 
> > You can still get into trouble if the air gets round the bleed screw thread
> > itself - the less you need to open that, the better!
> >
> > Dave
> > UK VW Type 3&4 Club
> > ===================
> >
> > -----Original Message-----
> > From: type3-vwtype3.org-bounces at lists.vwtype3.org
> > [mailto:type3-vwtype3.org-bounces at lists.vwtype3.org] On Behalf Of Know One
> > Sent: 02 August 2011 15:28
> > To: type3 at vwtype3.org
> > Subject: Re: [T3] bleeding brakes question
> >
> > > I'm a little confused on the gravity
> > > system.  How do you get the air bubbles out?  Please explain the
> > > procedure in a little more detail. I've always used a helper.
> >
> > Have been a terrible brake bleeder in the past I finally found a process
> > that works for solo brake bleeding.
> >
> > The key is to run the drain line from the bleeder -up- and then down to a
> > container. By having it up hill of the bleed valve, bubbles go -up- and
> > away
> > from the valve. Bubbles at the end of the valve will be sucked back up into
> > the cylinder if the tube runs directly down.
> >
> > By doing this you can press on the brake pedal without the need for a
> > helper.
> >
> > I have confirmed this on my '64 Ford truck (which has lots more clearance
> > than a VW). I was under watching what happened when my son pressed on the
> > brakes and released with the bleeder tube heading up. It works great, there
> > is very little drawback into the cylinder on the pedal return, but it draws
> > fluid not air since the bubble went up and away from the valve. You do have
> > to wait a little for the bubbles to move up.
> >
> > Be sure to keep an eye on the master cylinder reservoir.
> >
> > Jeff '67 Sqbk - with great brakes, but a gas leak! however I'm on vacation
> > in Montana, so won't get to fixing for at least a week.
> > For those asking about the parts I found at a VW show, I won't have access
> > to anything until I return home.
> > _______________________________________________
> > VWType3.Org mailing list - type3 at vwtype3.org
> > http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org
> > Contact gregm at vwtype3.org if you need help with the list.
> >
> > _______________________________________________
> > VWType3.Org mailing list - type3 at vwtype3.org
> > http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org
> > Contact gregm at vwtype3.org if you need help with the list.
> >
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <http://lists.vwtype3.org/private.cgi/type3-vwtype3.org/attachments/20110802/92b19dbd/attachment.htm>
> _______________________________________________
> VWType3.Org mailing list - type3 at vwtype3.org
> http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org
> Contact gregm at vwtype3.org if you need help with the list.
 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.vwtype3.org/private.cgi/type3-vwtype3.org/attachments/20110802/a9e05d68/attachment.htm>