Copy of: Front Brake Pads

[Mike Wattam <MikeWattam@domain.elided>]

Dear All

In response to emails from Ian Cunninham and Peter Howells, below is a copy
of an e-mail I sent out over a week ago.  If anybody would like a copy,
please let me know within the next 24 hours.

If you have already ordered your copy of the full report, it will be
despatched to you then.

Please note that although the report does refer to brake squeal there is no
consistent answer to this irrespective of car model, pad type, material,
items fitted including shims etc.  There are new cars being made today
which will do this and changing any part might cure the problem on one car,
but not the next apparently identical car.  One car will only respond to a
disc change, while the next is totally unresponsive unless new pads are
fitted etc., etc., etc.,

Also, while asbestos-free pads can give a light and responsive feel
initially, they did not stand up at all well to heavy braking from speed to
zero.  When they were noisy, they were REALLY noisy.

The box in which the pads come is no real guide to the actual manufacturer.
 For instance the original manufacturer (Lockheed) admitted to
sub-contracting manufacture and stated they could not guarantee individual
part quality - strange but that IS what they said.

IMHO - Mike Wattam
Chairman - Triumph Stag Register

---------- Forwarded Message ----------


RE:     Copy of: Front Brake Pads

Dear All

At long last, I have completed exhaustive tests in relation to the Stag
'front brake pad' objections recently raised by another club.

Please note these tests took considerable time and cost, and are not to be
taken lightly (but they did really annoy a guy in a Cessna!).  8 separate
combinations of pad were tried in various conditions including roller brake
tests and high speed braking (thus the runway) including pedal effort
required.

Below you can read a summary of the findings.  The complete report is also
available (including pictures) on request from me.  It is a PDF file that
should be downloadable by most modems/ISP's in a couple of minutes.  It
will need Acrobat Reader to be able to read it (downloadable from the Adobe
Website) as the file otherwise would be 5Mb long.

Please note that neither the report itself nor the following remarks are to
be reproduced in any manner either electronic or in paper format, for use
by any other person whatsoever without obtaining specific prior written
permission from myself.

IHMO - Mike Wattam
Chairman - Triumph Stag Register

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Summary

There are three different specifications of brake pads which have been
supplied for the Stag.  The early type symmetrical pads operate well with
the Stag and the later 'offset' specification 2 was only introduced to
prevent brake noise and for no other known purpose.  The latest
specification 3 is asbestos-free pads with a locating tag and offset
linings.  The anti-squeal properties of the 'offset' brake pads is not
proven as in one test with offset pad material, pronounced brake squeal was
noticeable.

There would need to be considerable imbalance in the braking from side to
side of the car before any noticeable swerving under braking would result. 
With one front brake hose partially clamped to restrict force/response on
that brake, the Stag was much more difficult to stop - obviously - but was
perfectly controllable to stop in a straight line.  This may not be the
case when the rear brakes are seized.

There was no practical braking advantage discovered in rolling road or
real-life tests for any permutation of pad configurations on the car. 
Therefore it was concluded that there was no evidence whatsoever to support
the claim to that only 'offset' pads fitted the 'right' way up must be
used.

Further, the quality of pads supplied is very poor from many sources.  It
is necessary to closely check the pads you purchase to ensure they meet
specification 3 before attempting to fit to the car.  This is not for
safety reasons as has been erroneously claimed without any supporting
evidence - but if you continue to use the standard Stag brakes it is
recommended that the current specification 3 is used, as otherwise
responsibility for accidents arising from 'incorrectly fitted' brake pads
may be voided by motor insurers.

The Stag brakes when fitted with the current specification 3 asbestos-free
pad linings do not stand up well to very arduous conditions.  This is the
only really important factor to bear in mind from the tests, and is one
which has not been documented before.

Yet again, this raises the question of the importance of fitting uprated
brakes such as supplied by Monarch and Brighton Stag Specialists.  These
suppliers of uprated brakes have been 'rubbished' in another magazine for
no proven justifiable reason.  I know what I'll be doing.  When I do and
assuming I have time to do it, I'll let the results of proper tests be
known.  Please note that neither the author nor the TSR has any vested
interest in either of these companies.

Mike Wattam
Chairman - Triumph Stag Register