BRAKES FROZEN OR LOCKED. Lining frozen to brake drum. Release air line frozen due to moisture in the system.
Broken air line, fitting or seals. Damaged lining jammed between drum and shoe. Wedge return spring broken jamming
unit.
FRONT AXLE AND STEERING
Carriers in heavy duty service require careful attention to front axle and steering maintenance. Special attention should be
given to checking all difficulties as the safety of the operator and carrier is directly concerned.
HARD STEERING. May be due to under-inflated tires, front wheel misalignment, excessive friction, lack of lubrication, or
loss of power assist.
LOW SPEED SHIMMY. Caused by incorrect caster, front brake drums out-of-round, worn steering knuckle bearings or
loose wheel bearings.
HIGH SPEED SHIMMY. Generally due to the tire or wheel assembly not being balanced, unequal tire inflation or worn and
maladjusted steering mechanism.
TIRES
Tires should be carefully checked for inflation and condition before each trip. The following wear characteristics
indicate the need for alignment work:
INCORRECT TOE-IN. When tire wears from outside to inside of tread with feather edge on inside of rib, and generally is
more pronounced in the right tire.
INCORRECT TOE-OUT. When tires wear from inside of tread to outside edge of ribs and is usually more pronounced on
the left tire.
INCORRECT CAMBER. Excessive camber causes wear on the outside half of the tire and wear of this type usually
takes the form
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