Document byM19wge2jqXrJ2JG1p4eLqOy
ENGINEERING AND MANUFACTURING STAFF
March o 1986
to: Mr, R- J.Donnell an cci Mr. R. S. Krause
Subject: COMMENTS ON TWO EPA MEMORANDA FROM MR. R. S- KRAUSE
1. Atny Moll memo -from Weil and Del pi re. dated October 17. 198S
I am in agreement with the data and commentary
of this
document. The authors also feel that the value from Rohl (of
29.3 f/cc, 1^76) was not representative of typical brake
service. As I recall, but not with much clarity,
this was
discussed with (I believe) Sinai's Arthur Danger. My opinion
then, more firm today, is that such high values result 'from
measurements on a drum brake that was!
a. of inferior initial quality {e.g. using a drying oil
or similar low grade binder resin; and was
b. e>iDosed to long periods of high temperature (e.g. hard
braking and/or parking brake left dragging for some time);
and then c. worn, with attendant very high brake lining wear rates
and resultant friable fiber release.
The only other mechanism that could lead to such high fiber emissions during service would appear to be from high lining wear rates, with prolonged 1dw rubbing speeds, after severe rusting of the cast iron and/or from rust bonding of the cast iron to lining. This is a statistically improbable. though
possible, usage situation.
The TWA value of 0.04 f/cc that was suggested does aopear to be reasonable and correct for most service mechanics, based on the information at my disposal.
2. Amy Moll memo tfrom ICr Corporation, dated March 13, 1935
There is an air Df superficiality to this document.
It is
fraught with numerous errors of both technical data and of
apparent fundamental understanding. For example:
p5/Pl Nuturn's comments were not interpreted correctly here. Flexibility during forming is not a major problem in finding asbestos substitutes for drum brakes,
p5/P2 Disc brakes are not new (Lancaster's patent on disc brakes was before 1910). Disc technology did not develop due to pressure from car downsizing.
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pA/Pl "Most heavy vehicles use drum brakes
brake blocks" Tch! Tchl
which
are
called
p6/P2
Brake tooling is not done according to wheel size, as
suggested. However, retooling may be needed -for the different
disc brake designs used in -foreign cars. Asbestos substitution
e-f-forts at Bendi>: concentrated on the larger markets, not the
1arger brakes#
p7/P2
Non--asbestos linings, in some cases, are being re-fitted
to brakes that originally were asbestos-based.
That does not
make them equal or equivalent. In general, a-ftermarket linings
are cheaper, poorer wearing (esp. at elevated temperatures),
and less stable fnctionally than DEM.
Sears dropped an
advertizing blitz on their non-asbestos brake linings when they
became aware o-F their attendant performance shortcomings.
plh/Pl
The aftermarket for drum brakes is larger than that for
disc brakes because many older vehicles were all--drum, where
now thev are tvpically disc-'drum combinations.
plO/P2
For
per vehicle.
four, blocks
al 1 #
heavy trucks there are eight blocks per a>:le, not The heavy truck brake is assumed to have two, not
per brake# Trailer brakes were not addressed at
pll/PT There are many more lining manufacturers than 21 m the
USA.
Bendix and Raymark fnow BSD do not supply a majority of
the market. The reference for this was listed in the appendix
as the owner of a brake rehne shop! The aftermarket estimate
also appears tD be in error, where Brazil, Mexico, and Korea
apparently were not included.
The above comments cover less than half of the 'ticks' I made
to the memo. I called several of the persons interviewed and
referenced.
One, Francis Hudson of Abex, did not even recall
having the telephone interview and was displeased that he had
been referenced without having been told of, or shown, the
text.
The 'interviews' were exclusively by telephone, from January IS
to March 7, 1935# Published references were poorly selected,
such as Loken's infamous SAE paper that
contained
much
misinformation
about
Kevlar
and
non--asbestos
friction
materials. Since the memo was dated March 13, 1985, the
author(s) apparently wasted little time m completing this
draft. The header stamp showed it to be an Asbestos Ban
Support Reference. It is disheartening to think that important
EPA decisions may be based on memos of such dubious quality.
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A. E. Anderson SRLYE1152
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