[s-cars] Bleeding brakes

[Erik Addy]

Ahh, that make more sense.  Speaking of these valves, if I recall mine was pretty stiff last time I was working on the brakes.  Should it move pretty freely?  Can it be lubed or should it be replaced?

Erik




________________________________
From: Steve Mills <s.b.mills at gmail.com>
To: Erik Addy <erikaddy at yahoo.com>
Cc: s-car-list at audifans.com
Sent: Sat, October 31, 2009 7:40:24 PM
Subject: Re: Bleeding brakes

Sorry for any confusion- "closed" probably isn't the best choice of words- "up" is probably better, assuming up is defined to correspond to suspension movement. The problem with both descriptions is since it's a proportioning valve, it probably isn't 100% "closed" or 100% "open", anywhere in it's range of motion- all the way "down" (suspension at full droop) is the most restrictive, all the way "up" (valve wired up- no simple way to fully compress that corner) is the least restrictive, but in both positions it is still limiting flow to the rear brakes to some extent.

Main point is to avoid the common mistake of bleeding the brakes with the car on stands without knowing there's a proportioning valve in the circuit and ensuring that it's not limiting the bleed by wiring it "up".

Steve


On Sat, Oct 31, 2009 at 8:32 PM, Erik Addy <erikaddy at yahoo.com> wrote:

Why wired closed?  I would think you would want it wired open to get fluid thru the valve as easy as possible?
>
>Erik
>
>Date: Mon, 26 Oct 2009 22:33:16 -0400
>From: Steve Mills <s.b.mills at gmail.com>
>Subject: Re: [s-cars] Upgrading stock UrS brakes
>To: Jerry Scott <jerryscott at wispertel.net>
>Cc: s-car list <s-car-list at audifans.com>
>Message-ID:
>    <7f8cd2c10910261933o6a0d43edla9caa2f1d3339ea1 at mail.gmail.com>
>Content-Type: text/plain; charset=ISO-8859-1
>
>I am not a fan of stainless lines, and having run both back-to-back there
>isn't significant difference in pedal feel with the stock brakes. Most of
>the "mush" in the G60 setup appears to be due to caliper design and
>mounting- I've tried many different pads with no real effect.
>
>The only thing I've seen that has significantly improved the feel of stock
>brakes is making sure that the proportioning valve is wired closed during
>bleeds on the early cars (build date through June of 1995). This is very
>frequently overlooked and results in horrible pedal feel.
>
>
>
>