User Manual

SERIES 50 OPERATOR'S GUIDE
DrivingonFlat,Dry
Pavement
Use the following guidelines when
driving on flat, dry pavement:
1. If driving on flat,dry,open
stretches wit h a light load and
greater slowing power is not
required, place the progressive
brakingswitchintheLOW
position.
2. If you find you are still us ing the
service brakes, move the switch
to a higher position until you do
not need to use the service brakes
to slow the vehicle down.
3. If you are carrying a heavier load
and road tractio n is good, move
the progressiv e braking switch to
the “High” position.
4. Check your progressive braking
switch often for proper po sitio n,
since road c on dition s can change
quickly. Never skip a step when
operating the progressive brakin g
switch. Always go from OFF
to LOW, and then to a higher
position.
Descending a Long, Steep
Grade
An explanation of “control speed”
may b e helpful in understan din g how
to use the engine brake system while
descending a grade. Control Speed
is the constant speed at which the
forces pushing the vehicle forward on
a grade are equal to the forces holding
it back, without using the vehicle
service brakes. In other words, this
is the speed the vehicle will maintain
without using the service brakes or
fueling.
BRAKE FADE
To avoid injury, do not over
apply the vehicle service brakes
when descending a long, steep
grade. Excessive use of the
vehicle brakes will cause them
to heat up, reducing their
stopping ability. This condition,
referred to as “brake fade”, may
result in loss of braking, which
could lead to personal injury or
vehicle/property damage or bo t h.
Use the following guidelines when
descending a long, steep grade:
1. Before beginning a long, steep
descent, first determine if you r
engine brake system is operating
properly by lifting your f oot
briefly off the throttle. You
should feel the system activate.
2. When descending the grade,
make sure the progressive braking
switch is in the appropriate power
position.
All information subject to change without notice. (Rev. 01/04) 43
DDC-SVC-MAN-0058 Copyright © 2004 DE TROIT DIESEL CORPORATION