<VV> Another Brake Question

[N. Joseph Potts]

I've seen no answer to this question by Wednesday, so here goes:

All I can think of (and I'm straining my imagination) is that your shoes are
not accurately arced to the drums. This is common enough, and there are
various ways of fixing this INCLUDING just continuing to drive. EVENTUALLY,
they will arc themselves, if you can stand to wait for what may turn out a
long process.
     And I HAVE thought of something else. You mention new front drums. New
drums are typically supplied with a preservative film on the surface the
shoes bear on. Did you clean this surface (with alcohol) before installing
new drums? If you didn't, it's too late - either grin and bear it and see if
it goes away, or get new front shoes. By the way, you should clean turned
drums in a similar manner, but it might not be necessary in every case.
     You don't mention replacing the springs in your brakes. If this problem
continues (to concern you), consider replacing all the springs. The springs
are NOT hard to find (vendors) nor are they expensive. As for how hard they
are to put on, well, you already know that.
     If you pull your rear drums, measure them for: (a) diameter over 9.56
inches; (b) runout over specification; and (c) taper. You can get a gauge
designed for this purpose from the auto supply or (I expect) our vendors. It
is not expensive.
     Some Corvairs came with finned drums. Not to worry if the drums are
Corvair.

Joe Potts
Miami, Florida USA
1966 Corsa coupe 140hp 4-speed with A/C

-----Original Message-----
From: virtualvairs-bounces at corvair.org
[mailto:virtualvairs-bounces at corvair.org]On Behalf Of Roger Gault
Sent: Monday, June 06, 2005 9:17 PM
To: Corvair List
Subject: <VV> Another Brake Question


This weekend I rebuilt my '65 convertable's brakes.  Now they have this
weird "flutter" to them.  When I apply the brakes, I feel a high frequency
(maybe 10-20 times the wheel rotation rate) vibration or flutter.  By the
end of my 15 mile commute (mostly freeway), it's nearly gone, but it comes
back the next time I drive it.

Work done:
  Replaced all 4 rubber brake lines
  Rebuilt wheel cylinders
  Replaced shoes
  Turned rear drums
  New front drums
  New right front wheel bearings
  Repacked left front wheel bearings
  Replaced the oval spring on the emergency brake reaction rod in left rear
brake.
  Replaced emergency brake cable.
  Bled system

Did not:
  Check turned rear drums
  Sand surface of new front drums

So, smart guys, have you ever seen this before?  If it was grabbing, I'd
think contaminated shoes.  If it was at wheel speed, I'd think warped drum.
But, as it is, I'm baffled.

Thanks,
  Roger

PS:  The new front drums have small fins on the outside, which I am
concerned might be touching the wheels (stock 13"), but I was tired and
hurrying when I put the wheels on and did not check.