Date:         Thu, 26 Mar 2009 18:15:53 -0400
Reply-To:     Ed McLean <email99@BELLSOUTH.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Ed McLean <email99@BELLSOUTH.NET>
Subject:      Re: Pulsating Brake Pedal (Need Solution)

You can try cleaning the drum and then reinstall the wheel, torquing the lug
nuts to 129 ft-lbs in a star pattern with a torque wrench evenly in three
steps.

You have to torque the lugs yourself every time you have your wheels mounted
by someone else because you just can't get any tire shop to do this
properly.  Never, ever let anyone mount a wheel "NASCAR style" using an
impact wrench, even if they say they will check it with a torque wrench.
They simply don't understand that your concern is not that the lugs might be
too loose but that you don't want them too tight.  I've had a Volvo dealer
service manager argue until he was blue in the face that lugs were torqued
properly (to 63 ft-lbs on the Volvo) because his technician used a "torque
stick" with his impact wrench.  I then got him to loosen the lug nuts with
his expensive SnapOn torque wrench and and watched his face get redder and
redder as he found that lug nut after lug nut required considerably more
than 150 ft-lbs of torque to remove, even though they had been tightened
only minutes earlier.  Improperly torqued wheel lugs can cause pulsing
brakes and tires that shimmy.

If you suspect something is bent you can then check the mounted wheel
assembly for roundness by rotating the wheel while the bus is jacked up and
comparing the edge of the rim to a pointer that is siting on something on
the ground.  This will show both out of round and wobble in the wheel and/or
the tire, depending on what you are measuring.  I doubt, however, from your
explanation that this is a problem.

If this doesn't fix it, replace the brake drum and brake shoes on both sides
with new stuff.  The drum is probably out of round or it has overheated and
cooled unevenly.  Either of these will cause uneven braking resulting in
more uneven heating of the drum and the problem will get even worse.  If you
turn the drum to remove the out of roundness you will have a drum surface
that is too large in diameter for the shoes to make good, even contact and
you will have poor braking.  You might have an smooth surface but the
chemistry and thickness of the metal will still be non-uniform and cause
uneven braking.

I had problems with pulsing brakes on my Vanagon for years until I did the
ultimate brake fix.  I replaced the thin unvented front discs and the rear
drums with oversize vented Audi disc brakes.  These suckers are about an
inch thick and have remained absolutely true.  The braking performance is
simply amazing and is oh so smooth.  It was one of the best modifications
I've done in my 18 years of Vanagon ownership.

I hope this helps.

Ed