[T3] bleeding brakes question

[Dave Hall]

The specific instruction in the VW Factory literature is to do the front
circuit first on the dual circuit brakes.

This is to ensure there is resistance from the front circuit to allow the
rear circuit to be bled.  I assume this applies to bleeding by pumping the
pedal.  It may not matter if you use a pressure bleeder on the reservoir.

Whether to do the left or right wheel first would depend on which side the
steering wheel is.  LHD would be the right wheel first; RHD would be left -
ie the one further from the master cylinder.

I thought single-circuit brakes were always done furthest first, which would
be passenger rear, driver rear, passenger front, driver front.   

As Jim says, they don't usually seem to give much trouble, though sometimes
I suspect that air gets in the bleed screw if it's opened too much.  Any
problem of that nature can be solved by having a helper push on the pedal,
and only open the screw momentarily when there's pressure on the fluid.
Just raising the end you're doing can help if they're being stubborn to
bleed.  

Most of us use a simple tube with or without a one-way valve.  I use a
rubber tube with a blocked end and a slit in the side, with a collecting
bottle and hang it on the bleed screw.  No real cost and has worked fine for
decades without a need for a helper!

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 Jim Adney
Sent: 01 August 2011 05:46
To: type3 at vwtype3.org
Subject: Re: [T3] bleeding brakes question

On 31 Jul 2011 at 16:22, Bryon Garvin wrote:

> On a dual circuit MC, it wouldn't matter if you bled your brakes by 
> starting in the front vs rear, or vice versa, correct?  I have 
> sometimes heard of starting at a particular wheel and going in some 
> specific order.  But seems to me the circuits are independent and it
wouldn't matter.

I've wondered about this for years, but never come to a sound conclusion.
The only thing I think helps is to do the RR before the LR. If I really
thought hard about it, I would probably do

RR
LR
LF
RF

But it really doesn't seem to matter if you're willing to go around a second
time. And if you do it by gravity and just let it take its own time, it
doesn't seem to matter at all. Almost any pattern works as long as you don't
let the reservoir go dry and suck air into the MC. 
If you do that, you get to start all over again.


--
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************

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