Medium Duty Operator's Manual - Peterbilt Motors Company

DASH- AND DOOR-MOUNTED FEATURES
Fog Lights Switch
CONTROLS AND DISPLAY
Air Suspension Deflate Switch (Dump Valve)
AIR SUSPENSION
If your vehicle has fog lights, turn them ON or OFF with
the control panel switch with the symbol shown above.
NOTE: Across the U.S.A. and Canada, State/Provincial
requirements vary as to when high beams
and fog lights can and cannot be used together.
Some states allow only four lights to be used
together, while some allow more. How your lights
are arranged will affect whether you can operate
headlights and fog lights concurrently—always comply
with the state or provincial requirements where you are
driving.
Your Peterbilt vehicle may have an air suspension deflation
switch which allows the air in the suspension to be
exhausted from a switch on the dash. The purpose of this
feature is to allow you to lower your tractor to get under a
trailer. You may notice a guard over the switch. This prevents
you from accidentally deflating the suspension.
WARNING! Operating the Air Suspension
Deflate Switch (Dump Valve) while driving can
lead to an accident. Sudden deflation while
your vehicle is moving can affect handling
and control. Use this switch only when your
vehicle is not moving.
– 52 – Y53-6008A Medium Duty (R05/09)