Date:         Mon, 16 Jul 2007 17:41:52 -0700
Reply-To:     Evan Mac Donald <macdonald1987@SBCGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Evan Mac Donald <macdonald1987@SBCGLOBAL.NET>
Subject:      Re: Some brake tech/ideas (long)
In-Reply-To:  <001101c7c808$2d120e00$4e19e442@dhanson>
Content-Type: text/plain; charset=iso-8859-1

Yup, I did. Flat-spotted the tires while I was at it! Those tires had only been on my van about a week, too. Boy, was I cheesed! Those were the standard 1985 set, just with new pads. I have since changed to 1991 brakes, for a slight upgrade.

Don Hanson <dhanson@GORGE.NET> wrote:  Brakes are fairly straight forward..no pun intended.

The brakes on my 84 are in perfect shape, and they aren't very good
brakes. I know good brakes from my Porsche racing days.

I've had just one close call in my Van because of inadequate brakes, but I
live in a rural area and drive "pretty far up the road" from my own vehicle,
so I don't encounter many situations where inadequate brakes are going to
kill me...but I will soon be changing to some better front ones, at least.

Here's the deal..Your brakes should be capable of locking up the wheels
under hard braking. Mine do not do that. You can test your own brakes by
finding a large deserted paved area and applying them hard, while going
straight, to see if you can lock your front wheels..It should not hurt
anything, but make sure your interior is free of loose objects..
.If you have ABS (dunno if Vans came so equipped) you should feel a buzzy,
pulsey vibrating, telling you that your wheels are starting to slide...and
the ABS IS working.
Over 80% of your braking force is supplied by the front brakes. So if
and when you find that yours are not capable of locking the front wheels at
full application, that's where you should make changes. Once your brakes
are capable of making your wheels lock up, then you look towards your tires
for better braking..
I have not yet looked to see which brakes might bolt right over to a
vanagon, but in order to diminish the stopping distance for any vehicle, a
few principles apply. The first is traction. If the traction you have can
overcome the amount of braking force your brakes apply (as is the case in
my 84 van) you need to get more braking force. That's done by increasing
the friction on the brake rotor or increasing the rotor's diameter or a
combo of both.
If you increase the friction on the rotor, you will create more heat..That
will become a concern if you use max braking for a long period of time, but
not so much if you just are forced to panic stop. I would think there
should be a better caliper for the front of the Vanagon, one capable of
squeezing harder..that is one place to look. Increasing the diameter of the
brake rotors also should be do-able. Or both. Those little front brakes
look more appropriate for something like a Rabbit than a heavy van..
Has anyone ever locked the front wheels of their van during an emergency
stop in their van? On dry pavement, of course..
Don Hanson