
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 227
If the cruise control is turned back
on while the vehicle speed exceeds
what is set prior to the cancellation
of cruise control, the set vehicle
speed cannot be changed until the
vehicle reaches to the set speed.
Also, the vehicle speed must be 1
MPH below the previously set
vehicle speed.
If you hold the switch at the +RES
position, the vehicle will keep going
faster until you release the switch or
apply the brake. So unless you want
to go faster, do not hold the switch
at the +RES position.
Exhaust Brake Function
Diesel Vehicles Equipped with
Exhaust Brake-interlocked Cruise
Automatic activation of the exhaust
brake during cruise control driving
suppresses an increase in the
speed on a downhill slope,
decreasing the need for the driver to
apply the regular brake pedal. The
exhaust brake does not activate
when the exhaust brake switch is
turn off.The maximum slope angle at which
the system can control the vehicle
speed increase is different
depending on the load the vehicle is
carrying.
Automatic Activation and
Automatic Release of Exhaust
Brake
The exhaust brake is engaged when
the vehicle speed exceeds the set
speed on a downhill slope.
The exhaust brake is disengaged
when the vehicle slows down close
to the set.
Fuel
Fuel for Diesel Engines
Diesel Fuel Requirement and
Fuel System
Fuel Requirements
Use of fuels other than ultra
low-sulfur fuel may not conform to
emission regulations.
The fuel supply pump, injector or
other parts of the fuel system and
engine can be damaged if you use
any fuel or fuel additive other than
those specifically recommended by
the dealer.
To help avoid fuel system or engine
damage, pay attention to the
following:
.
Some service stations mix used
engine oil with diesel fuel. Some
manufacturers of large diesel
engines allow this; however, for
your diesel engine, do not use
diesel fuel which has been
contaminated with engine oil.
Besides causing engine

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
228 Driving and Operating
damage, such fuel can also
affect emission control. Before
using any diesel fuel, check with
the service station operator to
see if the fuel has been mixed
with engine oil.
. Do not use any fuel additive
(other than as recommended
under "Biocides" in Water in
Fuel 0231). At the time this
manual was printed, no other
fuel additive was recommended.
(See your authorized dealer to
find out if this has changed.)
. Take care not to run out of diesel
fuel. If you do run out of fuel,
you may need to bleed air out of
the supply pump to re-start the
engine after fuel has been filled.
Your vehicle is designed to use
either Number 1-D or Number 2-D
diesel fuel. However, for better fuel
economy, use Number 2-D diesel
fuel whenever possible. At
temperatures below -7 °C (20 °F),
Number 2-D fuel may pose
operating problems (see "Cold
Weather Operation" which follows).
At colder temperatures, use Number 1-D fuel (if available) or use a
"winterized" Number 2-D (a blend of
Number 1-D and Number 2-D). This
blended fuel is usually called
Number 2-D also, but can be used
in colder temperatures than Number
2-D fuel which has not been
"winterized". Check with the service
station operator to be sure you get
the properly blended fuel.
Do not use fuels other than those
recommended in this manual. Doing
so may adversely affect the engine.
DIESEL FUEL/APPLICABLE
STANDARD (Sulfur content below 15ppm)
ASTM
(AMERICAN
SOCIETY FOR
TESTING and
MATERIALS) Based on D975
Number 1–D
S15 or Number
2-D S15 (below
15 ppm)Biodiesel
Biodiesel, may also be referred to
as FAME blended (Fatty-acid methyl
ester) fuel is a renewable fuel
produced from vegetable oils or
animal fats that have been
chemically modified to make it
compatible with diesel fuel.
Caution
Do not use home-made biodiesel
or home test kits because the
quality cannot be verified by
approved scientific methods. Do
not use raw vegetable oil or other
unmodified bio-oils, fats,
or blends of vegetable oil with
diesel. They could damage the
fuel system and engine, and
damages would not be covered
by the vehicle warranty.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 231
At low temperatures, wax flakes are
more likely to form in Number 2-D
fuel than in Number 1-D (or
"winterized" Number 2-D) fuel. For
best operation at temperatures
below -7 °C (20 °F), use Number
1-D, or Number 2-D which has been
blended with Number 1-D for winter
use. When temperatures are
consistently below (or near) -18 °C
(0 °F), use Number 1-D if at all
possible. Bear in mind, however,
that even Number 1-D fuel will form
wax flakes when temperatures are
extremely low.
Do not use home heating oil or
gasoline in your diesel engine;
either may cause engine damage.
The addition of kerosene will not
unplug a filter plugged with wax.
Warming a "waxed" filter to a
temperature of 0 °C to 10 °C (32 °F
to 50 °F) will return the wax to
solution. Filter replacement is not
normally required.Water in Fuel
During refueling, it is possible for
water (and other contaminants) to
be pumped into your fuel tank along
with the diesel fuel. This can occur if
a service station does not regularly
inspect and clean its fuel tanks, or if
a service station receives
contaminated fuel from its
supplier(s).
To protect your engine from
contaminated fuel, there is a water
separator system on the engine
which allows you to drain excess
water from the fuel.
{Warning
The drained water/diesel fuel
mixture is flammable, and could
be hot. To help avoid personal
injury or death and/or property
damage, do not touch the fuel
coming from the water separator
drain valve, and do not expose
the fuel to open flames or sparks.(Continued)
Warning (Continued)
Be sure you do not overfill the
drain pan. Heat (such as from the
engine) can cause the fuel to
expand. If the container is too full,
fuel could be forced out of the
pan. This could lead to a fire and
the risk of personal injury and/or
vehicle damage.
Biocides
In warm or humid weather, fungus,
and/or bacteria may form in diesel
fuel if there is water in the fuel.
Fungus or bacteria can cause fuel
system damage by plugging the fuel
lines, fuel filters or injector. They
can also cause fuel system
corrosion.
If fungus or bacteria has caused fuel
system problems, you should have
your authorized dealer correct these
problems. Then, use a diesel fuel
biocide to sterilize the fuel system
(follow the biocide manufacturer's
instructions). Biocides are available

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
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234 Driving and Operating
2. Select the correct fuel (See"Diesel Fuel Requirement and
Fuel System"). Follow any
posted safety rules. Stand to
the side, never above or
opposite the filler opening.
3. Check that the fuel cap is tight, and see to it that engine oil,
engine coolant in the reservoir,
and washer fluid, etc. are at
proper levels. Then do the
Driver Daily Checklist.
See Owner Checks and Services
0 340.
Driving your vehicle until the fuel
tank is empty may activate the
check engine malfunction indicator
light. You do not need to have your
vehicle checked. After refueling,
perform the following:
. Bleed the fuel system.
. Start, turn off and restart the
engine three or four times.
. The check engine malfunction
indicator light will be cancelled. Before Starting the Engine
1. The priming pump (1) is
located on the outboard side of
the left frame rail, in front of the
batteries. Place a container
beneath the air bleed plug (2)
to receive fuel, and then fully
loosen the plug.
2. Attach a clear hose onto the air bleed plug, direct the clear
hose into a catch pan.
3. Pump the priming pump (1) up/ down for 65 times to get most
of the air bubbles out. Note fuel
was drawn into the filter bowl at
around 40 - 50 times. 4. Fully retighten the air bleed
plug (2) and wipe off any fuel
that may have adhered to the
plug or surrounding area.
5. Continue to operate the pump for 50 times.
6. Start the engine.
7. If the engine does not start, repeat steps 5 and 6 as
necessary until it does start.
After Starting the Engine 1. Without pressing the accelerator pedal, start the
engine.
2. After the engine has started, allow it to idle for about
5 seconds.
3. Fully press the accelerator pedal and increase the engine
speed to the maximum speed
for 10 seconds. (Repeat this
operation several times.)

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 239
Vehicle Care
General Information
General Information . . . . . . . . . . 240
California Proposition65 Warning . . . . . . . . . . . . . . . . . 240
California Perchlorate Materials Requirements . . . . . 240
Accessories and Modifications . . . . . . . . . . . . . . . . 240
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 241
Cab Tilting . . . . . . . . . . . . . . . . . . . . 243
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 244
Engine Cover . . . . . . . . . . . . . . . . . 245
Engine Oil . . . . . . . . . . . . . . . . . . . . 245
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 251
Engine Air Cleaner/Filter . . . . . . 253
Engine Coolant . . . . . . . . . . . . . . . 253
Engine Overheating . . . . . . . . . . 259
Power Steering Fluid . . . . . . . . . 262
Washer Fluid . . . . . . . . . . . . . . . . . 262
Brakes . . . . . . . . . . . . . . . . . . . . . . . 263
Brake Fluid . . . . . . . . . . . . . . . . . . . 268
Battery - North America . . . . . . 269 Fuel Filter . . . . . . . . . . . . . . . . . . . . 270
Rear Axle (Gear Oil Viscosity
Chart) . . . . . . . . . . . . . . . . . . . . . . . 271
Rear Axle (Oil Level Check) . . . . . . . . . . . . . . . . . . . . . . 272
Noise Control System . . . . . . . . 272
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 274
Wiper Blade Replacement . . . . 275
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 277
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 277
Headlamps and Front Turn Signal . . . . . . . . . . . . . . . . . . . . . . . 280
Roofmarker Lamps . . . . . . . . . . . 284
Sidemarker Lamps (Including Turn Signal and Cornering
Lamps) . . . . . . . . . . . . . . . . . . . . . . 284
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 286
License Plate Lamp . . . . . . . . . . 286
Interior Lamps . . . . . . . . . . . . . . . . 287
Electrical System
Electrical System Overload . . . 287
Wheels and Tires
Wheels and Tires . . . . . . . . . . . . . 295
Tire Pressure . . . . . . . . . . . . . . . . . 307
Tire Rotation . . . . . . . . . . . . . . . . . 307
If a Tire Goes Flat . . . . . . . . . . . . 310
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 311
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 315
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 317
Interior Care . . . . . . . . . . . . . . . . . . 323

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
242 Vehicle Care
chock the wheels. It would be very
dangerous if the vehicle started
to move.
When performing work on the
electrical system, begin by turning
the engine control switch to the
"LOCK" position, wait at least
3 minutes, and then disconnect the
negative cable from the negative
terminal on battery. If the negative
cable is disconnected within
3 minutes, the engine control
module may malfunction.
When working on the fuel line or
fuel filter, remove the fuel tank filler
cap. The fuel system is under
pressure and the fuel will overspill
unless the pressure is relieved,
possibly leading to combustion or
a fire.
Do not make engine adjustments
yourself. Be sure to consult your
dealer.
Use only appropriate tools.Oils, brake fluid and engine coolant
have lubrication, cooling and rust
prevention functions. If these liquids
deteriorate through loss or
contamination, it will cause a
decline in the performance of the
parts and such problems as seizure
or malfunctioning. Replenish or
change these liquids when
performing the checks (daily and
periodic checks) as required by the
relevant regulations or in
accordance with the Maintenance
Schedule (when either the specified
driving distance or period of time,
whichever comes first, has expired).
Confirm that all systems and
components are normal after
performing the work.
Do not leave the removed parts or
tools in the engine compartment.
They could damage the equipment if
caught in the belts or other moving
components.
Dirty water, dirt and other impurities
seriously impair the effectiveness of
the oil, grease and fluids, and
damage the parts. Exercise all due
caution to prevent waste or otherrefuse from coming in contact with
parts or materials that have been
removed when changing or
replenishing them.
Do not step on the engine or climb
onto it. You could cause an engine
failure by, for example, damaging
the cylinder head cover or various
connectors.
Electric Welding
Careless electric welding of vehicle
parts can cause welding current to
flow back through the vehicle’s
ground circuit and damage electrical
and electronic parts so that they do
not function normally. Whenever
electric welding is necessary,
consult your dealer.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 245
Engine Cover
Engine Inspection Cover (Crew
Cab Model)
To gain access to the engine,
release the catch hooks (3) and
raise the passenger’s seat
cushion (2). The cover can be held
up by a strap (1), permitting engine
inspection and adjustment. Engine Inspection Sub Cover
(Crew Cab Model)
To gain access to the engine
compartment, pull the lock lever
(red) (1) on the driver
’s seat
cushion (2) to unlock it, raise the
driver ’s seat cushion and remove
the sub cover. Engine Coolant Reserve Tank
Inspection Cover (Crew Cab
Model)To gain access to the engine
coolant reserve tank, remove the
inspection cover located under the
rear left seat.
Engine Oil
Engine oil is an important factor
determining engine performance
and longevity. Be sure to use only
the specified oil and oil filters. The
engine oil level must be checked

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
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246 Vehicle Care
and the oil should be changed
regularly according to the
Maintenance Schedule.
The engine oil performs the
following important functions:
.It prevents engine parts from
becoming worn.
. It cools engine parts.
. It cleans engine parts.
. It seals the combustion
chambers and prevents rust.
Replace the engine oil at regular
intervals.
When particulate matter (PM) has
accumulated to a preset level in the
diesel particulate filter (DPF), the
filter is automatically regenerated
through combustion. To make this
regeneration (combustion) possible,
a small amount of fuel is injected
into the engine combustion chamber
after firing. This causes fuel to
gradually become mixed with the
engine oil, and the engine oil level
may rise beyond the original level.
This does not indicate a malfunction
of the engine.Access to the Engine
Single Cab Model
Access to the engine oil dipstick is
located on the engine left side after
tilting the cab. See Cab Tilting
0 243.
Crew Cab Model
The engine oil dipstick is under the
engine inspection sub cover located
beneath the driver's seat.
Checking the Engine Oil Level
Press the engine oil level check
switch. If engine oil level is low the
red oil pressure warning light will
turn on. If the engine oil level is
above the "OK", the green oil level
indicator will turn on.
The oil level varies while the engine
is running, right after it is stopped,
and on sloping ground. When
checking the oil level, be sure the
vehicle is on level ground while the
engine is cool.