Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
148 Driving and Operating
Vapor Lock :If the brakes overheat
due to frequent use, the heat can
cause the brake fluid to boil so that
air bubbles are created in the brake
fluid. Pressing the brake pedal
simply compresses the air bubbles;
pressure is not transmitted to the
wheel cylinders, so the brakes'
effectiveness sharply deteriorates.
This phenomenon is called
vapor lock.
Even so, you should be very careful
when using engine braking in a low
gear because the engine is likely to
over-rev.
See Exhaust Brake 0222 and
Selector Lever 0214.
Do not adjust the exhaust brake
valve.
The engine should never be allowed
to exceed the governed speed.
Supplement the exhaust brake with
vehicle service brakes intermittently
and/or shift to higher transmission
gear to prevent engine overspeed.
A rule of thumb for gear selection is
that the vehicle should be driven
down a grade in the same gear that
would be used to climb that grade.{Warning
To reduce the risk of personal
injury, before going down a steep
or long grade, reduce speed, turn
on the exhaust brake and shift the
transmission to the next lower
gear. This will help control your
speed. Do not hold the brake
pedal down too long or too often
while going down a steep or long
grade. This could cause the
brakes to get hot and not to work
as well. As a result, the truck will
not slow down at the usual rate.
Failure to take these steps could
result in loss of vehicle control.
You and others could be seriously
injured.
Brake Effectiveness When the
Vehicle Has Been Driven on a
Flooded Road or Washed
{Warning
When the vehicle is driven on a
flooded road, parked on a flooded
road or washed, water can get
into the brakes and reduce their
effectiveness. If the brakes do not
work well afterward, drive slowly
and gently press the brake pedal
several times until the brakes dry
out and start working normally.
Always do this after driving
through water or washing the
vehicle to help reduce the risk of
personal injury. Before parking
the vehicle in winter, press the
brake pedal several times in the
same way to get rid of moisture in
the brakes. Otherwise, the
moisture in the brakes may freeze
and make the vehicle immovable.
You and others could be seriously
injured.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 153
has been parked. If the brakes do
not work well, drive slowly and
gently press the brake pedal several
times until the brakes dry out and
start working normally.
Parking in Cold Regions
When snow collects around the
wheels and the lights, try to remove
it before night falls.
Do not apply the parking brake in
extremely cold weather, such as in
temperatures or at below 0 °C (32 °
F). If you leave the parking brake
applied, the wires and brake shoes
could freeze up, making it
impossible for you to release the
parking brake. Be sure to park the
vehicle in gear.
Be sure to put chocks against the
tires.
Whenever possible, park in a
garage to help prevent parts from
freezing up and to help make the
engine easy to start.
{Warning
If you park in a place where there
is a lot of snowfall, snow
accumulating around the vehicle
could limit ventilation. Running
the engine with the vehicle in
these conditions could cause
exhaust gases to enter the cabin,
resulting in carbon monoxide
poisoning. Take preventive action
by, for example, clearing the snow
around the vehicle.
You and others could be seriously
injured.
Do not park under trees or under
the eaves of a building. Chunks of
ice could fall on the vehicle if you
park in such a place.
Cleaning the Vehicle after
Driving on Snowy Roads
. The vehicle speed sensors are
fitted on the wheels. When
removing snow, ice, and other
incrustation, take great care not
to damage the components. .
Do not use a sharp implement to
remove snow. Sharp edges
could damage rubber parts.
Refer to Antilock Brake System
(ABS) 0216.
Remove snow that has stuck to the
inside of the fenders and to the
brake hoses. Otherwise, it may
damage components. After driving
on a salted road, wash the
underside of the vehicle as soon as
possible to prevent the salt from
causing rust. Spraying water under
high pressure is an effective way to
get the salt off.
After washing the vehicle, wipe the
door openings dry.
If the Vehicle Is Stuck
When Driving on Bad Roads
Caution
Do not spin wheels faster than
32 km/h (20 mph) in mud, sand,
snow, ice, or other poor road (Continued)
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
160 Driving and Operating
SymptomCauseCorrective Action Reference
Not enough engine power Parking brake not fully
released
Make sure it is fully
released
-
Brake dragging
4-
Air cleaner clogged
4-
Fuel filter clogged
4-
Engine control system
faulty
4-
Common rail system
faulty
4-
Engine faulty
4-
DPF clogged
4-
Brakes not effective Drum-to-lining gap too
large
4-
Air in brake fluid
4-
Brake system failure
4-
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
166 Driving and Operating
Mechanical Driveshaft Brake
Burnish Procedure
It is recommended that the
driveshaft mounted parking brake
be burnished as part of the new
vehicle break-in procedure.
Increased parking brake
performance will result when the
parking brake is burnished as
specified below:
.Make 10 moderate stops, using
the hand brake, from 16 km/h
(10 MPH) while spacing the
stops a minimum of 4 km
(2.5 miles) apart.
. Operate the vehicle at 32 km/h
(20 MPH) between stops.Pedals
Sit in a correct driving position on
the seat and operate the brake
pedal (1) and accelerator pedal (2)
with your right foot. To avoid
accidentally pressing the wrong
pedal, check the pedal positions
and practice putting your foot on the
desired pedal.
{Warning
A can or bottle rolling on the floor
may prevent brake pedal
operation if it is caught under the
pedal. This is very dangerous.
A floor mat must be placed
correctly. An incorrectly installed
floor mat may hinder the free
movement of each pedal. You
and others could be seriously
injured.
Ignition Positions
Engine Control Switch
{Warning
While driving, never turn the
engine control switch to the
LOCK position. The key could be
removed from the switch, which
then locks the steering wheel.
This is extremely dangerous.
You and others could be seriously
injured.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
168 Driving and Operating
4 START :On all engines, start is in
the position furthest clockwise. The
engine is started in this position.
Turn the key against spring
pressure to energize the starter.
When key is released, spring
pressure returns it to the ON
position. Release the key as soon
as the engine has started.
If the key cannot be turned from the
LOCK position to the ON position,
lightly move the steering wheel
clockwise and counterclockwise
while trying to turn the key.
Starting and Stopping the
Vehicle
Check around the Vehicle before
Starting the Engine
Proper care and operation will not
only extend the service life of your
vehicle but also improve fuel
economy.
Before pulling away, perform a
thorough safety check, making sure
there are no children or obstructions around the vehicle. Take off the
chocks after confirming that the
parking brake is securely applied.
Sit behind the wheel, adjust the seat
position, and buckle up the seat
belt. The passengers are also
required to buckle up the seat belts.
Adjust the positions of the steering
wheel and mirrors. Lock the doors.
Turn the power of the dome light or
accessories OFF before starting the
engine. See
Seat Position 038,
Seat Belts 043, Steering Wheel
Adjustment 065, and Mirrors033.
Keep the Floor Around the
Driver's Seat Clean and Tidy{Warning
It is extremely dangerous to have
empty cans, empty bottles or
other items rolling around on the
floor because they could get
trapped under the brake pedal
and prevent brake application.
For proper pedal operation, it is (Continued)
Warning (Continued)
also essential to lay floor mats
properly. Incorrectly installed floor
mats would hinder free movement
of the pedals.
Do not use the dashboard pocket
or the top of the dashboard as a
place to put items that could roll,
which could interfere with your
driving. You and others could be
seriously injured.
Choose Your Footwear Suitable
for Driving
{Warning
Choose footwear that ensures
proper operation of pedals when
driving the vehicle. Use of
footwear unsuitable for driving
may cause an accident.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 169
Starting the Engine
Do not keep the engine control
switch in the START position for
more than about 10 seconds.
Operating the starter for too long
might cause starter and battery
failure or may result in overheating.
When the engine does not start,
wait for 20 to 30 seconds and then
turn the engine control switch again.
Before starting the engine sit in the
driver seat, check that the parking
brake is firmly engaged, the selector
lever is in the P or N (P is preferred)
position and the shift indicator also
shows P or N, and firmly press the
brake pedal to start the engine.
When stopped on a slope, start the
engine with the selector lever in the
P position. SeeIgnition Positions
0 166.
1. Make sure that the selector lever is in the P or N position
and firmly press the brake
pedal.
2. When the engine control switch
is turned to the ON position,
the wait-to-start light comes on
and it goes out in about
1 second when the engine is
warm, to about 10 seconds
when the engine is cold.
3. After confirming that the wait-to-start light has gone out,
turn the engine control switch
to the START position to start
the engine. Release the engine
control switch as soon as the
engine starts.
4. Do not crank the engine for more than 10 seconds at a
time. If the engine does not
start, wait 20 to 30 seconds
with the engine control switch
in the LOCK or ACC position
before trying to start again. It is normal for the vacuum warning
buzzer to sound for a few seconds
after the engine has started.
After the engine has started, check
to be sure the selector lever is still
in the P position.
This engine has an automatic
warm-up system that increases
engine idle speed and applies the
exhaust brake. Allow sufficient time
to let the engine circulate lubricant
oil before driving. This usually
requires 30 seconds to 2 minutes
depending on ambient conditions.
See
Brake System Warning Light
(Parking Brake Light) 074.
The turbocharged engine should be
started in a way which ensures the
bearings supporting the rotating
parts of the turbocharger are
sufficiently lubricated. Do not race a
cold engine.
At low ambient temperatures, a cold
engine may emit more smoke than
usual.
Do not drive the truck until the
engine has had sufficient time to
circulate the lubricant oil. This
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
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Driving and Operating 171
3. Always refuel at the end of aday's operation. Moisture will
condense in an empty tank;
therefore, the tank should be
filled before leaving the vehicle
standing for an extended
period.
Do not use starting aids in the air
intake system. Such aids can cause
immediate engine damage. See
Fuel for Diesel Engines 0227.
Stopping the Engine
When stopping the engine, take the
following steps: 1. Bring the vehicle to a complete stop.
2. Firmly apply the parking brake.
3. Move the selector lever to the P position and make sure that
the shift indicator shows P.
4. Allow the engine to idle for approximately 3 minutes.
5. Turn the engine control switch to the ACC or LOCK position. Do not shut down the engine
immediately after driving the vehicle.
Otherwise, a seizure or other
failures may result.
To prevent the battery from going
dead, turn the engine control switch
to the ACC or LOCK position after
stopping the engine. If you leave the
vehicle for an extended period of
time, place the engine control switch
in the LOCK position.
Let the engine idle for 3 minutes
before shutting off the engine. This
allows the turbocharger to slow
down while keeping the bearings
lubricated.
If the Vehicle Has Not Been Used
for a Long Period
If a diesel vehicle has been
standing for an extended period of
time, the turbocharger bearings
should be pre-lubricated prior to
starting. See your authorized dealer
for more detailed information.
Before using a vehicle that has not
been driven for a long period, check
the engine and transmission for oil
leakage, and make sure the oil is at the required levels. If there is
insufficient oil, it will not adequately
reach and lubricate components,
and a breakdown will result.
Start the engine and allow it to idle
for at least five minutes. Check for
abnormal noises.
For instructions on warming up the
engine, refer to
“Starting the Engine”
previously in this section.
If one year has passed since the
diesel exhaust fluid (DEF) in the
DEF tank was added, the DEF in
the tank should be replaced. Be
careful not to inhale the ammonia
odor when replacing the DEF. Also,
please contact your nearest dealer
about the replacement work.
Operating Temperature
Recommendations for Warming
Up the Engine
The engine is sufficiently warmed
up when the needle of the engine
coolant temperature gauge starts
to move.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
174 Driving and Operating
Idle Shutdown
Idle Stop is a dealer programmable
function which will automatically turn
off the engine, at idle, when specific
programmed conditions are met.
See your dealer for details. When
the Idle Stop light comes on, it alerts
you that programmed conditions
have been met and the engine is
about to shut down. This light stays
on after the engine has stopped.
This indicator light will come on
when the engine control switch is
turned to the ON position and then
should go out after approximately
3 seconds.
If the idling stop function does not
initiate, a transmission related
problem may have occurred. Please
contact your dealer. (There is a
Diagnostic Trouble Code (DTC) that
inhibits the idling stop function when
the Service Transmission Warning
Light is not illuminated).
High Idle System
Use high idle mode to increase
engine idle speed to 1,200 r/min
when the vehicle is stationary.
Activating High Idle Mode
Follow the below procedure to
activate the high idle mode:1. Set the parking brake.
2. Set the selector lever in P (Park) or N (Neutral) position.
3. Do not press the brake pedal.