Date:         Sat, 14 Sep 1996 11:54:22 -0400
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         jag@cs.rochester.edu
Subject:      Re: Knocking in 1983 transporter

In article <51dt4h$ltj@mn5.swip.net> you write:
>I have a VW transporter from 1983. When I use the brakes I can
> hear a knocking from the left rear wheel the last seconds before
> the car is brougt to standstill. The brakes do not show any faults
> and in spite of installation of a distanceplate which moved the 
>brakedrum 1,5 mm the knocking is still there. If I reverse and brake
>there is no knocking. Does anyone know what could be wrong?
>Anders Andersson.

I get this knocking sound for a while after not using my '82 VW Westy for
a month or so. I've assumed it comes from the drum being slightly
corroded under the brake shoe, where it can trap condensation, and
less corroded elsewhere. The knocking usually stops after a few days
use of the van. Then the corroded surface is polished clean again.
Beware however that a severely corroded surface will wear your
brake shoes very quick, and the drum may get groved and uneven.

Another possibility is that the drum is slightly out of round. I don't
know why there is a difference when you go forward and backward. I
never tested this myself when I had the knocking. It is not strange
that it behaves differently though, since the twisting forces on the brake
assembly are different in reverse and forward.

I would carefully check the brakes once more, and if that doesn't
reveal anything take a look at more unlikely causes (in suspension and
drive shafts (CV's).

/Martin ('82 VW diesel camper bus (Westfalia))

PS How much does a descent condition early 80's VW bus cost in
Sweden? Can you find the Westfalia campers also?

PPS There is a really cool internet club/mailing list for VW busses, check:
	http://www.automatrix.com/~skip/volkswagen/
for info. I'll crosspost this to them, to see who can come up with a better
hypothesis of what's wrong with your brakes.

-- 
Martin Jagersand                 email: jag@cs.rochester.edu
Computer Science Department             jag@cs.chalmers.se
University of Rochester          Fax:   (716) 461-2018
Rochester, NY 14627-0226         WWW: http://www.cs.rochester.edu/u/jag/