Date:         Mon, 9 Feb 2004 11:58:30 -0700
Reply-To:     mark brauer <beeser750@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mark brauer <beeser750@EARTHLINK.NET>
Subject:      Re: wisdom of DOT 5 brake fluid (kinda long)
In-Reply-To:  <200402071935.1aPFJy2Aa3NZFl40@penguin>
Content-type: text/plain; charset="US-ASCII"

George, you're absolutely correct with regard to the need to remove all
traces of DOT3/4 before converting a brake system to DOT5.  You're also
correct that IF people conducted the proper maintenence of their brake
system (like flushing and replacing the fluid every 3-4 years), most of the
problems associated with DOT3/4 water absorbtion would be eliminated.
However, regular maintenence is a dirty term in the US of A, and so in the
real world, it's simply not done.

(I will also say here that every ABS system I've come across specifically
warns against using DOT5 in the system.  I'm not sure why that is, but until
I do more investigation, I wouldn't consider changing a vehicle so equipped
over to DOT5.)

The best method for cleaning brake lines and the rubber bits is to use the
purest isopropyl alcohol that can be obtained from your local pharmacy.
Most auto parts stores sell "brake cleaners" that come in spray cans which
work pretty well for the metal parts, but you really need to soak the
rubber, and the spray stuff is too evaporative (and expensive) for soaking
purposes.  The alcohol will remove all traces of DOT3/4.

Remove the master and wheel cylinders, disassemble and clean them thoroughly
with the alcohol.  Or, rebuild them with new rubber kits, or replace the
entire units with new or rebuilt ones.  Before re-installing them, flush out
the lines.  There are numerous methods for forcing the alcohol through the
brake lines without removing them from the vehicle; I just use a syringe
with a rubber hose, one line at a time, blocking off the other three at the
wheel cylinder ends.  I then blow out the lines with clean, compressed air
(using a water and oil separator, of course!), and let everything sit for a
day or two to dry out.  (This is best NOT done during the rainy season.)
Re-install everything, and bleed thoroughly with DOT5.  I like to flush
about 1/2 quart or so through before I close everything up, just to be that
much more sure of getting all the alcohol out.

Right now, DOT5 is about $18-$20 a quart.  I have not noticed, nor ever
heard of any problems associated with ambient moisture getting into the
system and causing problems; unlike DOT3/4, DOT5 does not actually draw
moisture to it.  It hasn't been very many years since I did my DOT5
conversions (8-years on the Vanagon, 3 on the '53 Cadillac), but I doubt I
will ever have any problems with my lines, both metal and rubber, rotting
from the inside out; nor have I experienced brake fade due to boiling brake
fluid (a problem I used to have with both of these vehicles); I don't have
to worry about spilling caustic DOT3/4 behind my dash or on any part of my
expensive paint jobs; and, I've given up spending a Saturday every three
years tearing up the floor of my Cadillac just to do regular maintenence.  I
don't know what the life span of DOT5 is, but it seems to be very long.  (I
have an '82 Sportster that had DOT5 installed from the factory, and outside
of pad replacement, it hasn't had any brake system repair done since, well,
EVER!  Still has the original fluid....)

Mark in Westminster, CO

> In a message dated 2/7/04 1:20:45 AM, jmeeks@GASLIGHTMEDIA.COM writes:
>
> << Could you elaborate on the "proper procedures" and perhaps any other
> benefits of using DOT 5 >>
>
> From my hard earned experience with DOT 5, the only proper procedure to
> retrofit it is to completely disassemble EVERY component of the braking system
> and
> thoroughly scrub them in hot soapy water.  Of course, after the cleaning all
> has to be dried completely.  One problem is how to clean the internals of such
> parts as brake equalizers and convoluted lines.  Another is how to swab the
> brake hoses which have end fittings with a smaller ID than the ID of the hose
> to
> which they are attached.
>
> As I have proven to my self on two separate occasions, flushing copious
> amounts of DOT 5 through the system will not remove all of the original fluid;
> enough of the original brake fluid will be left behind in the numerous nooks
> and
> crannies of the system to do damage.
>
> DOT 3/4 brake fluid is hygroscopic whereas DOT 5 is not.  On the surface,
> this might seem to be a very desirable quality, and it is, if it is used in
> its
> uncontaminated form in a SEALED system.  But, a Vanagon does not have a sealed
> system and since DOT 5 does not absorb moisture, bubbles of water will form in
> it.  The density of water being greater than the density of DOT 5 will cause
> the bubbles of water to migrate to the low points of the system where they
> will collect to do their nastiness.
>
> So, the proper procedure to replenish the brake fluid of a Vanagon with DOT 5
> would be:
> 1/ Antiseptically clean the system.
> 2/ Fill it from a fresh container of DOT 5.
> 3/ Devise some manner to seal the system.
>
> The alternative, which I recommend, is to flush the system with clean DOT 4
> every few years.  When I was addicted to DOT 5 some twenty years ago, it cost
> me $32 a quart.  I don't have any idea what it costs today, but I know that
> DOT
> 4 has to be MUCH cheaper with no palpable difference in its performance in a
> road car.
>
> George
>