Peterbilt Medium Duty Truck Owner's Manual - Peterbilt Motors

VEHICLE RECOVERY AND SPRING BRAKES
6. With a wrench, turn the
release stud assembly nut until
the compression spring is 90–
95 percent caged. While doing
this, check to make sure the
push rod (adapter push rod or
service push rod) is retracting.
Do not over-torque the release
stud assembly. (S–Cam type
maximum: 50 ft-lb, Wedge type
maximum: 30 ft-lb.) The spring
brake is now mechanically
released.
STARTING AND OPERATING THE VEHICLE
Freeing the Vehicle from Sand,
Mud, Snow and Ice
WARNING! Do not spin the wheels faster than
35 mph (55 km/h). Spinning a tire at speedometer
readings above this can be dangerous—
tires can explode from spinning too fast.
Under some conditions, a tire may be spinning
at a speed twice that shown on the
speedometer. Any resulting tire explosion
could cause severe injury or death to a
bystander or passenger, as well as extensive
vehicle damage: including tire, transmission
and/or rear axle malfunction.
If the vehicle gets stuck in sand, mud, snow, or ice:
• Move the gearshift lever or selector from First to
Reverse.
• Apply light pressure on the accelerator pedal while
the transmission is in gear.
• Remove your foot from the accelerator while shifting.
• Do not race the engine.
• For best traction and safety, avoid spinning the
wheels.
– 144 – Y53-6027 Medium Duty (R05/09)