[Vwdiesel] bad brakes on 2001 Jetta
Mark Shepherd
mark at shepher.fsnet.co.uk
Mon Jul 8 20:36:07 PDT 2013
Interesting discussion.
I've never used a powered/suction system, although I did make a failed bid on a Gunson's one recently. I naturally started on the 2 man system of holding
pedal down.
I moved on to a length of clear tube arching up and then down into a bottle. On the end of the tube is a ball bearing stuffed into the end. About 1/2" back up
the tube is a small bore hole.Pushed over the tube is a 'rubber' tube fitting tightly over the clear tube such that it goes say an inch beyond the hole back up
the line, creating a one-way valve that is biased to drip conveniently out the end under pressure.
I suspect that one factor for the brake failure s when bleeding may be more so on brakes that have been dormant for extended periods rather than just old
but used daily. I don't think that full strokes are necessary as long as the fluid is moving.Sufficient speed to overcome climbing air, although if that is an issue
I can't see why it doesn't climb during use and self bleed... I swear my Quantum does this to some extent! Can seals still be purchased? In the old days I
have packed behind the master cylinder seal to increase tension against the bore, and added a secondary seal behind the old one on British stuff.
To find out what is failing, I use a carb balancing vacuum gauge on the line. Check for max vac, response to pushes , overnight leaks etc Weak mk2 type
vane pumps can easily be improved by rotating the vanes. There are 3 spare 'new edges' enough to last some 60-to 75 years!
Mark
Does anyone have a do it yourself tire bead breaker they can recommend?
========================================
Message Received: Jul 08 2013, 05:54 PM
From: "Kneale Brownson"
To: "Rolf Pechukas"
Cc: "vwdiesel at vwfans.com"
Subject: Re: [Vwdiesel] bad brakes on 2001 Jetta
No more than 15 lbs. google home made brake bleeder.
Sent from my iPhone
On Jul 8, 2013, at 9:12 AM, Rolf Pechukas wrote:
> OK, so you guys are fighting about whether pedal pushing or power bleeding is preferable
>
> but in either case, you are using pressure to *push* fluid out at the bleed nipples
>
> no one is advocating vacuum bleeding - suction at the bleed nipples - which is what my mechanic was doing and I was questioning (was sucking air past
the threads, and you could never tell whether you had solid fluid or not)
>
> seems to me, ideal practice would be: constant compressor-based pressure at the reservoir, steady 25 lbs or whatever, pushing an extra 'column' of
brake fluid attached to the reservoir, so you don't ever run dry
>
> bleed nipples in order, then stomp pedal to drive any bubbles toward nipples, then bleed in order again, repeat until all air gone
>
> if I had the car, I'd do something like that
>
> any advice on how to suggest a pressure-based bleed to the mechanic? I don't want to pay him for the work and then have to re-do it myself - too much
other stuff going on
>
> thanks,
>
> Rolf in MA
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