WHEN Newsletter - Federal Safety Standards for Heavy Trucks - Part 1

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WHEN — Q3 2014
Dayton Parts LLC
(continued from page 7)
Regards,
Steven S. Wolf
Axle Group Product Manager
Dayton Parts, LLC
Dayton Parts, LLC • PO Box 5795 • Harrisburg, PA 17110-0795 • 800-233-0899 • Fax 800-225-2159
Visit us on the World Wide Web at
DP/Batco Canada • 12390 184th Ave. • Edmonton, Alberta T5V 0A5 • 800-661-9861 • Fax 888-207-9064
8
Look for the Part 2 continuation
of this edition of WHEN in the
Q4 Dayton Parts Distributor Mailing
0
10
20
30
40
50
60
70
80
90
100
110
120
Pressure (psi)
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
2 12
Initial Lining Temp (Deg °F)
Recovery Stops
4 14 6 16 8 18 10 20
Actual Wheel Load (lb) — 11451.7
2 Actual Inertia (slug/ft ) — 950
Brake Type — Meritor Drive
Rolling Radius (in) — 19.6
Slack Adjuster — Haldex 5.5"
Air Chamber — MGM 3030
Brake Drum — Webb 66864
Dayton Parts
DP23 Friction Material
Link Testing Laboratories, Inc.
DrumTemperature
Air Pressure
Brake Recovery
Brake Recovery – (continued)
Here’s what a typical brake recovery graph looks like.
This part of the test tells us if the friction material
can continue to create sufficient torque after it has
been subjected to higher drum temperatures. The
20 psi minimum is really a mute point now that ABS
is once again mandated (more about that in Part 2).
One last side note here. While reading through how
this test is conducted, the ability of the brake drum
to dissipate heat in a sufficient manner becomes
very obvious. You would not get the same results
shown in the charts here with a “value” drum.
In closing remember this test is only required for
friction materials that are seeking OE approval.
Aftermarket friction materials are not required to
have this test done in order to be sold. Most
aftermarket friction material manufacturers do have
this test done on their own accord which is good.
Never purchase any friction material where this test
cannot be supplied. In the next edition we’ll pick up
where we left off around 1980 and go to the present
plus a look beyond.
As always I hope you found this edition of WHEN
informative.