User's Manual

97
BW7248
GLOSSARY OF TERMS
FT: Fabricated, Tapered, Bendix’ term for brake design with a closed anchor pin rib. Interchanges with Rockwell
P design.
GAW: Gross axle weight
GAWR: Gross Axle Weight Rating, a rating in pounds of brake lining material, or axle carrying capacity.
GCW: Gross combination weight: the total weight carrying capacity of a combination vehicle as determined by
axle ratings.
GCWR: Gross combination weight rating
Grease-Stained Drum: A brake drum with discoloration of the friction surface caused by, for example, improper
greasing of brake camshaft.
GVW: Gross vehicle weight: the total weight carrying capacity of one vehicle, (such as a straight truck, bus,
tractor or trailer) as determined by axle ratings.
GVWR: Gross vehicle weight rating
HA: Suffi x used to denote brake shoes used on axles produced by Bendix’ Heavy Axle & Brake Division.
HDBMC: Heavy Duty Brake Manufacturer’s Council
Heat-Checked Drums: A brake drum with a pattern of hard, slightly raised, dark spots on its friction surface.
Caused by localized overheating and sudden cooling. Those spots should be ground off to prevent drum
cracking, uneven lining wear and loss of braking effi ciency. If spots cannot be removed, the drum should be
discarded.
Lining Growth: Permanent swelling of brake linings due to heat exposure.
Lining Number : Numbers shown are FMSI (Friction Materials Standards Institute) standards and fi t the
corresponding brake shoe core.
NHTSA: National Highway Transportation Safety Administration
Out-Of-Round Drum: A brake drum with variations in its inner diameter, causing reduced braking effi ciency
and excessive wear on one side of the brake linings. An out-of-round drum often can be machined, within
manufacturer’s limits, to restore concentricity.
Over-Sized Drum: This refers to a brake drum having an inner diameter greater than the discard diameter
marked on the drum by its manufacturer.
P Brake: Rockwell’s term for brake design with a closed anchor pin rib. Interchanges with Bendix FT design.
PM: Preventive maintenance
Polished Drums: A brake drum with a friction surface polished to a mirror-like fi nish by unsuitable brake linings.
Remove gloss from drum with eighty grit emery cloth.
Push Rod: A rod, protruding from a brake chamber, which is connected to the arm of a slack adjuster via a
clevis pin.
Q Brake: Quick-change, Rockwell’s term for brake design with an open anchor pin rib. Interchanges with
Bendix FC design.