freightliner WALK-IN VAN CHASSIS Operator's Manual page 60

Hydraulic and Air Brake Systems
Operation
Before driving the vehicle, secure all loose items in
the cab so that they will not fly forward during a full
brake application. Make sure that all occupants are
wearing seat belts.
During normal braking stops, depress the foot brake
control pedal until braking action slows down the ve-
hicle. Increase or decrease the pressure on the
pedal so that the vehicle comes to a smooth, safe
stop. When the forward speed of the vehicle has de-
creased to almost the idling speed of the engine,
push the clutch pedal in (if equipped) and shift the
transmission into Neutral (N). Apply the hand parking
brake if the vehicle is to be parked.
IMPORTANT: In the event of a total loss of ser-
vice brakes with full system air pressure, use
the parking brake control valve (yellow knob) to
bring the vehicle to a complete stop in the saf-
est location possible.
The yellow diamond-shaped knob on the control
panel actuates the parking brake valve. Pull out the
knob to apply the parking brake. See
03/30/2010
Fig. 7.2, Parking Brake Control Knob
WARNING
If the vehicle is equipped with an air suspension
system, do not move the vehicle with the air sus-
pension deflated. Doing so could result in a loss
of vehicle control, possibly causing personal in-
jury and property damage.
NOTICE
Do not use the spring brakes if the service
brakes are hot, such as after descending a steep
grade. Also, do not use the spring parking brakes
during freezing temperatures if the service
brakes are wet. To do so could damage the
7.3
brakes if hot, or cause them to freeze during cold
weather.
If the brakes are wet, drive the vehicle in Low (L) or
First (1) gear and lightly apply the brakes to heat and
dry them.
Allow hot brakes to cool before using the parking
brake. Always chock the tires.
Automatic Slack Adjusters
Automatic slack adjusters are required on all vehicles
equipped with air brakes manufactured after October
20, 1994. Automatic slack adjusters should never be
manually adjusted except during routine maintenance
of the foundation brakes (e.g., replacing shoes), dur-
ing slack adjuster installation, or in an emergency
situation.
When the brake pushrod stroke exceeds the legal
brake adjustment limit on a vehicle, there is likely a
mechanical problem with the foundation brake com-
ponents or the adjuster is improperly installed.
Visit a repair facility as soon as possible when
brakes equipped with automatic slack adjusters are
Fig. 7.2.
determined to be out of adjustment.
Manually adjusting an automatic slack adjuster to
bring the pushrod stroke within legal limits is
likely masking a mechanical problem. Adjustment
is not repairing. In fact, continual adjustment of
automatic slack adjusters may result in prema-
f421624
ture wear of the adjuster itself. Further, the im-
proper adjustment of some automatic slack ad-
justers may cause internal damage to the
adjuster, thereby preventing it from properly
functioning.
NOTICE