Paccar PX-9 Operator's Manual - page 51
OPERATING INSTRUCTIONS
WARNING!
DO NOT use the engine brake
when operating on surface with
poor traction (such as wet, icy, or
snow covered roads). Retarders
can cause the wheels to skid on
a slippery surface. You could lose
control of the vehicle and jacknife if
the wheels begin to skid, resulting
in an accident.
Failure to com-
ply may result in death, personal
injury, equipment or property dam-
age.
WARNING!
DO NOT use an engine brake
when driving bobtail or with an un-
loaded trailer. There may not be
enough weight on the rear axle to
provide traction. This could cause
a loss of control and jackknife re-
sulting in an injury accident. Make
sure the engine brake is switched
“OFF” when bobtailing or with an
unloaded trailer. Failure to com-
ply may result in death, personal
injury, equipment or property dam-
age.
CAUTION
Never exceed governed engine
speed because engine damage
can occur. Operating engine be-
yond the governed speed causes
additional strain on valve train and
internal engine components. Op-
erate the engine within governed
engine speed.
NOTE
Once you have determined what
the safe speed is for your vehicle,
operate the engine brakes with the
transmission in the lowest gear that
will not cause the engine speed
to exceed the rated engine speed.
The optimum braking power of the
engine brakes is reached at rated
engine speed. Correct gear selec-
tion, therefore, is critical.
The two-position selector switch can
be used to vary braking power as road
conditions change.
Vehicle service brakes must be used
when additional braking power is
required.
(12/2014)
Y53-1185-1B1
4-15
4