warning CHEVROLET LOW CAB FORWARD 2020 Owner's Manual

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
236 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
0 233.
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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 239
Change Intervals
The oil and oil filter change intervals
for your engine are based on the
use of recommended oil quality and
viscosity, as well as high-quality
filters such as genuine GM oil filters.
Using oil other than recommended,
or oil and filter change intervals
longer than recommended, could
reduce engine life. Damage to
engines due to improper
maintenance or use of incorrect oil
quality and/or viscosity is not
covered by the new vehicle
warranty.
Your engine was filled with a
high-quality engine oil when it was
built. You do not have to change this
oil before the first recommended
change interval. Oil and filter
change intervals depend on how
you use your vehicle. For
information on the proper oil and
filter change intervals. See
Maintenance Schedule0317. Engine Oil Additives
Engine oils contain a variety of
additives. Your engine should not
need any extra additives if you use
the recommended oil quality and
change intervals.
{Warning
Used engine oil contains harmful
contaminants that have caused
skin cancer in laboratory animals.
Avoid prolonged skin contact.
Clean skin and nails thoroughly
using soap and water–not mineral
oil, fuels or solvents. Launder or
discard clothing, shoes or rags
containing used engine oil.
Engine Oil and Gear Oil
Viscosity Charts
Select appropriate engine oil in
accordance with the table below.
It is also important to select the
viscosity appropriate for the
temperature at which your vehicle
operates. Use the following table for
making correct selections. Engine Oil
Engine oil viscosity (thickness) has
an effect on fuel economy and
cold-weather starting. Lower
viscosity engine oils can provide
better fuel economy; however,
higher temperature weather
conditions require higher viscosity
engine oils for satisfactory
lubrication.
When choosing an oil, consider the
range of temperature your vehicle
will be operated in before the next
oil change. Then, select the
recommended oil viscosity from the
chart.
Do not use any viscosity of oil not
recommended. Such oils could
cause engine damage.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 241
or bodies of water. Instead, recycle
it by taking it to a used oil collection
facility which may be found in your
community.
Automatic Transmission
Fluid
{Warning
Overfilling of the automatic
transmission can cause the fluid
to be "PURGED" out of the
breather hose onto the hot engine
parts and can cause a fire.
You and others could be seriously
injured.
Both quality and quantity of fluid are
important factors that have a
significant influence on the
performance and durability of the
automatic transmission. Be sure to
use only the dealer recommended
fluid for replenishment, and observe
the specified fluid level. Too much or too little transmission
oil could damage your transmission.
Too much could cause your
transmission to overheat and fluid to
spill out from the breather hose. Be
sure to get an accurate reading if
you check your transmission fluid.
When cleaning around the dipstick
and guide tube, make sure that you
thoroughly wipe away all of the dirt
and dust etc. Failure to do so may
cause a fault in the transmission.
Do not let coolants (ethylene glycol
type), water based substances,
or other fluids etc., mix with the
fluid. Otherwise, degraded
performance and faulty operation of
the system will result.
Checking the Automatic
Transmission Oil level
This operation could be difficult and
you may choose to have this done
at your dealer.
If you choose to do it yourself, then
be sure to follow all the instructions
below or you could get a false
reading on the dipstick.Position of the Dipstick
For the single cab vehicle, the
dipstick is located to the left side of
the automatic transmission at the
rear of the engine. Tilt the cab up to
inspect it.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 243
.Dipstick H (HOT) —
Transmission fluid
temperature Approx. 70 -
80 °C (158 - 176 °F).
. The “C (COLD)” range on
the dipstick is a guide used
by your dealer for
specialized equipment used
to replace or service the
automatic transmission
fluid. When performing your
own inspections, always
use the “H (HOT)” range
after warming up the
vehicle.
The fluid must be hot to
ensure an accurate check.
The fluid level rises as
temperature increases.
6. If the fluid level is too low, add the specified fluid through the
dipstick guide tube. Also, check
whether there are no fluid
leaks.
7. Insert the dipstick securely into position.{Warning
Be extremely careful not to burn
yourself when checking the oil
level if the engine temperature is
high. Protect yourself with
gloves etc.
You and others could be seriously
injured.
Discarded parts, oil, grease and
fluids could have an adverse effect
on the environment. It is difficult to
dispose of these, so have your
dealer handle all checks and
replacements.
Engine Air Cleaner/Filter
Air Cleaner
Using a clogged air cleaner element
not only reduces engine output but
also causes increased fuel
consumption and an increased DPF
regeneration frequency. Be sure to use a genuine air cleaner
element. If a different air cleaner
element is used, it may cause the
sensor to output a wrong signal.
See
Maintenance Schedule 0317.
Air Cleaner Indicator Light
When the air cleaner indicator light
comes on, check the air cleaner
element. If the air cleaner element is
clogged, replace the air cleaner
element.
See Vehicle Messages 074.
See Maintenance Schedule 0317.
Engine Coolant
Protection of Engine Against
Overcooling
Overcooling of the engine not only
accelerates wear of the vital engine
parts but also hurts fuel economy.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
244 Vehicle Care
Engine Coolant in Cold
Weather
To prevent the engine damage due
to freezing of the engine coolant,
mix the coolant and water at the
ratio of 50/50.
Replace rubber hoses whenever
they crack or are damaged; even
minor cracks allow engine coolant
solution to leak.
{Warning
If your engine cooling system
overheats, seeEngine
Overheating 0249. Continued
operation of the engine even for a
short time may result in a fire and
the possibility of personal injury
and/or severe vehicle damage.
You and others could be seriously
injured.
Your vehicle has an engine coolant
recovery system, expansion bottle
and/or an engine coolant reserve
tank system. Engine coolant in the
system expands with heat and overflows into the reserve tank.
When the system cools, engine
coolant is drawn back into the
radiator.
The engine cooling system has
been filled at the factory with a
quality engine coolant. It is
important to use proper engine
coolant to prevent damage to
engine cooling system components.
The engine cooling system is
designed to use engine coolant
rather than plain water. See
Recommended Fluids and
Lubricants
0339.
See the Maintenance Schedule to
find out when the engine coolant
must be replaced. Note that
changing the engine coolant is
needed to replenish the rust
inhibitors to make certain that all
parts of the engine cooling system
work well.
{Warning
Check, replenish or change the
engine coolant only after the
engine has sufficiently
cooled down.
Do not loosen or remove the cap
of the radiator or engine coolant
reserve tank cap when the engine
coolant is still hot. Hot vapor or
boiling water may burst out and
cause a burn.
When removing the radiator cap
or engine coolant reserve tank
cap, use a thick cloth to cover the
cap and turn it slowly.
Engine coolant is toxic and must
not be ingested. If the engine
coolant is mistakenly ingested,
seek prompt medical attention.
If the engine coolant gets in your
eyes, rinse your eyes immediately
with a large amount of water for
15 minutes or longer. Also, if your (Continued)

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 245
Warning (Continued)
eyes are still irritated or otherwise
feel abnormal, seek immediate
medical attention.
If the engine coolant gets on your
skin, rinse it off using a soap with
a large amount of water. Also,
if abnormality is seen, seek
medical attention.
Engine coolant is flammable, and
therefore, it must be kept away
from flames and other heat
sources. Engine coolant also
could ignite if it comes in contact
with a hot surface, such as the
exhaust manifold. Exercise
caution to prevent this from
happening.
You and others could be seriously
injured.
Preparing Engine Coolant
To prevent engine damage due to
freezing of the engine coolant and
to protect the cooling system from corrosion, use a mixture of the
recommended type antifreeze and
water. If the engine of the vehicle is
at
−30 °C (−22 °F) or above, the
coolant concentration should be
50%. Direct use of “50/50
Pre-diluted” product which is already
diluted to 50% concentration is
recommended. If the outside
temperature engine or vehicle is
used at −30 °C (−22 °F) or below,
coolant concentration of 55% is
recommended.
It is the owner ’s responsibility to:
. Maintain the engine cooling
system freeze protection at or
above −30 °C (−22 °F) (at or
below −30 °C (−22 °F) in colder
climates to ensure protection
against corrosion and loss of
engine coolant from boiling.
A 50/50 (55/45 for colder
climates) mixture of the
recommended type antifreeze
and water will provide freeze
protection to at or above −30 °C
(−22 °F), (at or below −30 °C
(−22 °F) in colder climates) and
boil protection to 128 °C (262 °F). Periodic replacement
of engine coolant is needed to
replenish the anticorrosion
additives that wear out with use.
Engine coolant that has become
dark in color shows that it needs
to be changed.
. Use only the recommended
coolant. See Recommended
Fluids and Lubricants 0339.
. Do not use methanol-base
antifreeze, alcohol or plain water
alone in your vehicle at any time.
They will boil at a lower point
than that at which the engine
coolant temperature gauge will
warn of overheating, and they do
not provide proper protection
against corrosion.
Engine Coolant Quantity
For the quantity of engine coolant,
see Capacities and Specifications
0 349. After changing the engine
coolant, check that the engine
coolant is up to the specified level.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
246 Vehicle Care
{Warning
For storage, close the cap of
coolant container securely and
keep it in a place inaccessible to
children.
You and others could be seriously
injured.
Using any coolant other than that
recommended by your dealer could
cause damage to the engine,
radiator or heater core. In particular,
use of coolants containing borate
salts or silicates may result in
engine or radiator corrosion,
causing engine coolant leaks and
other problems.
To dilute the coolant, use distilled
water or deionized water.
Do not use the coolant at any
coolant concentration other than
that specified. If the coolant
concentration is 60% or higher,
overheating is likely to occur, while
if it is 30% or lower, anti-corrosion
function is not provided sufficiently. Using coolant at any coolant
concentration other than that
specified may reduce anti-freezing
performance, and engine coolant
may freeze.
If the engine coolant decreases
rapidly, stop the vehicle in a safe
place and contact your dealer for
advice and repair.
Checking the Engine Coolant
Level
For the single cab model, the
engine coolant reserve tank is
located behind the front-right wheel.
See
Cab Tilting 0233.
For the crew cab model, the engine
coolant reserve tank is under the
access panel beneath the left rear
seat. See Engine Cover 0235.
When the engine has cooled down,
make sure that the fluid level in the
engine coolant reserve tank is no
lower than the “MIN”line. In
addition, carefully remove the
radiator cap and check to see if it is
damaged. Check that the engine
coolant is full to the filler neck.
Check the engine coolant level only
when it is cold.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 249
Engine Overheating
When the Engine Overheats
The engine cooling system may
overheat if the engine coolant level
is too low, if there is a sudden loss
of engine coolant (such as radiator
hose failure), or if other problems
occur. It may also temporarily
overheat during severe operating
conditions such as:
.Climbing a long hill on a hot day.
. Stopping after high-speed
driving.
. Idling for long periods in traffic.
If engine power drops and the
needle on the engine coolant
temperature gauge goes up above
the upper limit of the safety zone
and enters the "H" zone, the engine
is overheating. The engine overheat
warning light will come on and the
warning buzzer will sound. Either
steam or boiling engine coolant will
squirt out of the radiator. The
vehicle will also have an “OVERHEAT”
message displayed. Take the
following corrective actions
immediately.{Warning
To help avoid being burned:
Do not tilt the cab or open the
engine access cover if you see or
hear steam or engine coolant
escaping from the engine
compartment. Wait until no steam
or engine coolant can be seen or
heard before tilting the cab or
opening the engine cover.
Do not remove the radiator cap or
engine coolant reserve tank cap if
the engine coolant in the tank is
boiling. Also do not remove the
radiator cap while the engine and
radiator are still hot. Scalding fluid
and steam can be blown out
under pressure if either cap is
taken off too soon.
You and others could be seriously
injured. If Steam Is Coming from the
Engine Compartment
{Warning
If the engine coolant temperature
gauge shows an overheat
condition or you have other
reasons to suspect the engine
may be overheating, continued
operation of the engine (other
than as described here) even for
a short period of time may cause
a fire and the result in personal
injury and severe vehicle
damage. Take immediate action
as outlined.
You and others could be seriously
injured.
If you see or hear escaping steam
or have any other reason to suspect
there is a serious overheat
condition, stop and park the vehicle
as soon as it is safe to do so, turn
on the hazard warning flasher and
then turn off the engine immediately
and safely exit the vehicle.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
250 Vehicle Care
If Steam Is Not Coming from the
Engine CompartmentIf the engine coolant temperature
gauge shows an overheat condition,
or you have reason to suspect the
engine may be overheating, take
the following steps:1. Operate the hazard warning flasher and pull the vehicle
immediately over to a safe
place that does not impede
traffic and park it.
2. Idle the engine and wait until the engine coolant temperature
drops to safety zone. If your air
conditioner (if equipped) is on,
turn it off. And turn on the
heater to help the engine
expel heat.
3. When the needle of the engine coolant temperature gauge
returns to the middle of the
safety zone, stop the engine.
If the needle of engine coolant
temperature gauge does not
drop inside into the safety
zone, turn the engine off and
have your vehicle serviced at
the nearest dealer. When the cooling fan for the
radiator is not turning, turn off
the engine immediately.
{Warning
Even when the engine has been
stopped, the engine coolant in the
radiator remains under pressure.
Immediately removing the radiator
cap could cause steam or hot
water to blow out, and you could
be scalded as a result. The
engine coolant in the reserve tank
may also be hot. Immediately
removing the cap could cause hot
water to blow out, and possibly
scald you. Perform inspection,
refilling, and replacement of
coolant only when its temperature
has cooled.
When removing the radiator cap
and reserve tank cap, use a thick
cloth to cover the cap and turn it
little by little.
You and others could be seriously
injured.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
252 Vehicle Care
Power Steering Fluid
The power steering fluid level must
be checked and it must be changed
according to the Maintenance
Schedule. SeeMaintenance
Schedule 0317.
When replenishing power steering
fluid or flushing the power steering
system, always use ATF
(Dexron
®-VI). Failure to use the
proper fluid may damage the power
steering system seals and hoses,
leading to fluid leakage.
Checking the Power Steering
Fluid Level
The fluid level is correct if it is
between the “MAX”and“MIN” lines
on the power steering fluid tank.
If the level is lower that the “MIN”
line, add fluid up to the “MAX”line.
The reserve tank is located at the
rear of the engine compartment on
the right. When you have finished
checking the fluid level, securely
reinstall the cap and cover.
{Warning
Before adding fluid, clean the
area around the cap and pour
fluid from a clean jug or filler.
Foreign matter getting in the tank
may cause power steering system
failure.
Do not mix the recommended
power steering fluid with fluids of
other brands. Due to chemical
reactions, any mixture of
differently branded fluids may
cause failure of the system.
You and others could be seriously
injured.
Washer Fluid
Windshield Washer Fluid
The windshield washer is equipped
on the windshield wiper arm.
Check the level of fluid in the
windshield washer fluid tank. In
addition, spray windshield washer
fluid and operate the windshield
wipers to check for any areas not