2020 CHEVROLET LOW CAB FORWARD engine

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
232 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 orcontamination, 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 other
refuse 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 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 233
Cab Tilting
Before Tilting the Cab (Single Cab
Model)
{Warning
To help avoid personal injury and
property damage:. Park the vehicle on level
ground and check that there
is enough space in front of
and above the cab.
. Set the parking brake firmly
and block the front wheels.
. Move the selector lever in
the "P" position.
. Secure loose articles in
the cab.
. Stop the engine.
. Close the cab door.
. Keep the area surrounding
the cab clear.
You and others could be seriously
injured. Tilting the Cab
1. Check that all personnel are clear of the cab.
2. Unlock the handle (2) whilepulling the lever (1).
3. Hold the assist handle (3) andpull the safety hook (4).

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
234 Vehicle Care
4. Raise the cab fully and be surethe cab support (5) is locked by
the support lock lever (7).
5. Insert the safety lock pin (6).
Always be sure the safety lock pin is
installed when the cab is tilted.
{Warning
To help avoid personal injury or
death, keep hands, tools, and
clothing clear of the engine
cooling fan when the engine is
running.
You and others could be seriously
injured.
Lowering the Cab 1. Have all personnel stand clear of the cab.
2. Remove the safety lock pin (6). 3. Hold the assist handle (3) and
unlock the cab support by
pulling the support rearward
while pressing the support lock
lever (7).
4. Lower the cab and push the handle (2) down firmly to lock.
{Warning
To help avoid personal injury or
death, be sure the tilt cab is
securely locked in the lowered
position before operating the
vehicle.
You and others could be seriously
injured.
Engine Compartment
Overview

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 235
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 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 237
The engine oil level must be kept at
the right level to help assure proper
lubrication of your vehicle's engine.
It is the owner's responsibility to
check the oil level at regular
intervals (such as every fuel stop),
according to the following
instructions. Park the vehicle on a
level surface and check the engine
oil level before starting or at least
30 minutes after turning off the
engine.
1. Remove the oil dipstick (2) andwipe off any oil on the oil
dipstick.
2. Reinsert the oil dipstick fullyand then gently remove it.
The oil is at the correct level if
the oil level is between the
"FULL" and "MIN" marks.
3. If the oil level is too low, add oil to the "FULL" mark.
4. Reinstall the oil dipstick into position after checking the oil
level.
Any oil level above the "FULL" mark
on the oil dipstick may cause engine
malfunctions. The oil level cannot be checked
correctly when the engine is
running.
If the engine has been running, wait
at least 30 minutes before checking.
Adding the Engine Oil
When the engine oil level is near or
below the "MIN" mark on the oil
dipstick, remove the oil filler cap (1)
and add the oil. Remove the oil
dipstick (2) at this time. Use only the
specified engine oil.

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
238 Vehicle Care
Caution
When adding oil, be careful not to
spill any, but keep a workshop rag
handy just in case there are any
spills. If any oil should spill onto
the engine, carefully wipe it away.
If this precaution is not taken, the
spilled oil could ignite and a fire
could spread.
Do not leave flammable items,
such as rags or gloves, in the
engine compartment. They could
cause a fire. You and others could
be seriously injured.
Engine oil lubricates and cools the
engine's internal components. The
quality of the oil is degraded and the
quantity of oil is reduced by
evaporation, discharge and
combustion during the operation of
the engine. Continually using the
same oil without checking the level,
or without replenishing and
changing it could cause seizure or
damage to the engine. Prevent dirt from entering the filler
port when adding the oil. If foreign
matter mixes with the oil, it could
damage the engine.
Adding oil above the "FULL" mark
on the oil dipstick could result in
faulty engine operation. Be sure to
check the oil level by using the oil
dipstick.
Failure to use the recommended
engine oil could result in engine or
DPF breakdown, or in poor fuel
efficiency. Be sure to use the
recommended engine oil.
Choosing the Right Quality Oil
If you do not use the oil intended for
a vehicle equipped with a Diesel
Particulate Filter (DPF), both the
engine and the DPF may break
down and fuel economy may
decrease. Be sure, therefore, to use
the oil intended for vehicles
equipped with DPF.
GM recommends engine oil that
supports DPF (Low ash oil). Use of
engine oil that does not support low
ash will increase the PM produced
by engine combustion.Consequently, the maintenance
interval of the DPF filter will be
reduced.
Oil Identification Logo
A logo (symbol) is used on most oil
containers to help you select the oil
you should use. The top portion of
the logo shows the oil quality by API
designations such as CK4 or others.
The center portion of the logo
shows the SAE viscosity grade,
such as SAE *W-40 (* indicates
viscosity on the low temperature
side). You should look for this logo
on the oil container, and use ONLY
oil containing the logo.

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.