fuel CHEVROLET LOW CAB FORWARD 2020 Workshop 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
240 Vehicle Care
This Engine Oil Viscosity Grade
Chart shows general information.
For this vehicle, oil with *W-40
viscosity is recommended.
Changing the Engine Oil and
Oil Filter
Engine oil and the oil filter are
important factors in engine
performance and lifespan. Be sure
to use only the specified oil and oilfilters. The engine oil level must be
checked and the oil should be
changed regularly according to the
Maintenance Schedule.
Use the indicated oil quantities only
as guidelines when changing the
engine oil. After changing the oil,
make sure the oil is at the required
level. See
Capacities and
Specifications 0349. 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.
Engine oil change precaution:
.
When adding oil, remove the
dipstick.
. After adding oil, wait for at least
5 minutes before starting the
engine. Be sure to reinstall the
dipstick.
Discarded Parts, Oils and
Other Liquids
When changing oils, filters, engine
coolant or other liquids, be sure to
have a container ready in advance
for their disposal.
Use methods conforming to legal
requirements for discarding or
disposing of parts, oils, filters or
engine coolant after change or
replacement.
Do not dispose of used engine oil,
fuel or any other oil in a careless
manner such as pouring it on the
ground, into sewers, or into streams

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
260 Vehicle Care
Remember to check and recharge
the battery as necessary, as well as
keep connection clean.
The hydrometer (green-eye test
indicator) in the top of each battery
(if equipped) provides information
for testing purposes only.
If the vehicle is not going to be
driven for 30 days or longer,
disconnect the ground cable from
the negative (–) terminal of the
batteries to prevent discharge.
For full power needs at replacement
time, a battery with the same
specifications, as shown on the
original battery's label, is
recommended.
{Warning
WARNING:Battery posts,
terminals, and related
accessories contain lead and lead
compounds, chemicals known to
the State of California to cause
cancer and birth defects or other
reproductive harm. Batteries also
(Continued)
Warning (Continued)
contain other chemicals known to
the State of California to cause
cancer.WASH HANDS AFTER
HANDLING. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition
65 Warning 0230 and the back
cover.
Fuel Filter
Change the fuel filter in accordance
with the Maintenance Schedule or
when the fuel filter indicator light
(amber) comes on.
Drain the water when the water
separator (fuel filter) warning light
comes on. (Drain the water from the
chassis-side fuel filter and
engine-side fuel filter.) Failure to replace the fuel filter when
needed may lead to fuel system
damage. Your authorized dealer can
inspect your fuel filter and replace
your fuel filter, if needed.

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
284 Vehicle Care
No. Description Rating8 A/C 10A
Relay locations (1): No. Description
1 STARTER
2 ECM MAIN
3 NOX & DEF SENSOR
4 A/C COMPRESSOR
5 CONDENSER FAN
6 RR DOME LIGHT
7 SCR HEATER VALVE
8 MARKER LIGHT
9 –
10 –
11 FUEL HEATER When Slow-blow Fuses Blow Out
Slow-blow fuses protect the
electrical circuits, and they are
installed so that they can be quickly
replaced if there is a malfunction.
If an overload exists in the circuit
from the battery, the slow-blow fuse
will blow out before the wiring
harness is damaged to protect the
electrical circuitry. InspectionWhen the headlights and other
devices in the electrical system do
not work, but there is no problem
with the fuses, check the
slow-blow fuse.
The slow-blow fuse is blown if it
looks like the illustration.
Immediately contact the nearest
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 311
can cause serious damage to the
engine and its components,
particularly the fuel supply pump.
Handling the Radiator and
Charge Air Cooler
Cleaning the Radiator Core and
Charge Air Cooler Core
Cooling efficiency is compromised
when there is dirt or dust plugging
air passages in the radiator core
and charge air cooler core (diesel).This can also cause corrosion of
these cores. Wash the radiator core
with tap water every 24 months.
Make sure to turn the engine off and
remove the key from the engine
control switch before cleaning
cores.
The engine, exhaust pipe, and
radiator will be hot immediately after
the vehicle is driven. Be careful
around these parts to prevent burns.
Clean the engine when it is cold.
Do not clean the radiator, charge air
cooler (diesel) and their surrounding
areas using water that is supplied
under high pressure. Doing so may
cause 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 313
Underbody Maintenance
Corrosive materials used for ice and
snow removal, and dust control can
collect on the underbody. If these
materials are not removed,
accelerated corrosion (rust) can
occur on underbody parts such as
fuel lines, frames, floor pan and
exhaust system even though they
have been provided with corrosion
protection.
At least every spring, flush these
materials from the underbody with
plain water. Take care to clean well
any areas where mud and other
debris can collect. Sediment packed
in closed areas of the frame should
be loosened before being flushed.
If desired, your authorized dealer
can do this for you.
Interior Care
General
Remove dust and dirt from the
interior of the cab using an
automotive cleaner or vacuumcleaner, and gently wipe surfaces
clean using a cloth wet with warm or
cold water.
{Warning
Water should never be sprayed
directly into the interior of the cab
when cleaning. Failure to observe
this precaution can lead to vehicle
malfunction and possibly to fire if
water should enter the audio
system or other electrical
components located underneath
the floor carpet.
Petroleum ether, gasoline and
other organic solvents should not
be used to clean safety belts. In
addition, safety belt webbing
should be neither bleached nor
redyed. Failure to observe these
precautions can lead to the
performance or strength of the
safety belts being impaired. In the
case of a collision, therefore, the
safety belts could be insufficiently
effective, and serious
(Continued)
Warning (Continued)
life-threatening injuries could
result. When cleaning, use warm
water in which a small amount of
neutral detergent has been
dissolved to gently wipe the
safety belts.
Follow the manufacturer's advice
whenever cleaning agents or
other chemicals are used, inside
or outside the vehicle. Some
cleaners may be poisonous or
flammable, and improper use may
cause personal injury or damage.
When cleaning the inside or
outside of the vehicle, do not use
volatile cleaning solvents, such as
acetone, lacquer thinners, enamel
reducers, nail polish removers; or
such cleaning materials as
laundry soaps, bleaches or
reducing agents, except as noted
in the following fabric cleaning
advice on stain removal. Never(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
320 Service and Maintenance
No. Service Interval16 000 km/10,000 mi
24 000 km/15,000 mi
32 000 km/20,000 mi
48 000 km/30,000 mi
64 000 km/40,000 mi
72 000 km/45,000 mi
80 000 km/50,000 mi
96 000 km/60,000 mi
112 000 km/70,000 mi
120 000 km/75,000 mi
128 000 km/80,000 mi
144 000 km/90,000 mi
160 000 km/100,000 mi
168 000 km/105,000 mi
176 000 km/110,000 mi
Service intervals
months or
kilometers
(miles)
whichever
occurs first (1)
1 Engine noise check I - I I I - I I I - I I I - I
2 Valve lash - - - A - - - A - - - A - - - or every
12 months
3 Engine oil and oil filter (2) R - R R R - R R R - R R R - R or every
12 months
4 Fuel filter - R - R - R - R - R - R - R - or every
24 months
5 Pre-fuel filter/water
separator
- R - R - R - R - R - R - R - or every
24 months
6 Air cleaner filter - - - - - - - - - - - - - - - indicator (3)
7 Damage to air intake
ducts and hoses - I - I - I - I - I - I - I - or every
12 months
8 Drive belts I - I I I - I I I - I I I - I or every
12 months
9 Engine bolt torques - - - - - - I - - - - - I - -
10 Rotate tires Every 10 400 km (6,500 miles)

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
Service and Maintenance 321
No. Service Interval16 000 km/10,000 mi
24 000 km/15,000 mi
32 000 km/20,000 mi
48 000 km/30,000 mi
64 000 km/40,000 mi
72 000 km/45,000 mi
80 000 km/50,000 mi
96 000 km/60,000 mi
112 000 km/70,000 mi
120 000 km/75,000 mi
128 000 km/80,000 mi
144 000 km/90,000 mi
160 000 km/100,000 mi
168 000 km/105,000 mi
176 000 km/110,000 mi
Service intervals
months or
kilometers
(miles)
whichever
occurs first (1)
11 Engine cooling system I - I I I - I I I - I I I - I or every
12 months
12 Engine coolant Every 12 months: I
Every 24 months: R (when dealer recommended coolant is used)
13 Exhaust system I - I I I - I I I - I I I - I
14 DPF (clean filter) - - - - - - - - - - - - C - - or every
3,000 hours
15 DPF (pressure difference
sensor 0 point
adjustment) - - - - - - - - - - - - A - -
or every
3,000 hours
16 DPF (pressure difference
sensor hose) Every 160 000 km (100,000 miles): I
Every 400 000 km (250,000 miles): R or every
3,000 hours: I
17 Fuel line system I - I I I - I I I - I I I - I or every
12 months
18 Brake lining and pad
for wear I - I I I - I I I - I I I - I

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
326 Service and Maintenance
3. Engine Oil and Oil Filter :
Change at interval noted below
depending upon driving conditions.
•Normal Service —Change every
16 000 km (10,000 miles) or
12 months whichever occurs first.
• Severe Service —Change every
8 000 km (5,000 miles) or 3 months
if you often drive under one or more
of these conditions: (a) driving in
dusty areas, (b) frequent idling or
idling for long periods, (c) driving
6 km (4 miles) or less in freezing
weather, or other short trips in cold
weather, where the engine does not
thoroughly warm up.
Change oil and filter as soon as you
can after driving in a dust storm.
When recommended oil is used, it
conforms to this maintenance
schedule. (Recommended oil: CK-4
(API designations))
4. Fuel Filter : Replace the fuel
filter every 24 000 km (15,000 miles)
or more frequently if clogged or
replace when the fuel filter indicator
light comes on (if equipped). 5. Pre-Fuel Filter/Water
separator :
Replace the fuel filter
every 24 000 km (15,000 miles) or
more frequently if clogged or
replace when the fuel filter indicator
light comes on (if equipped).
6. Air Cleaner Filter : The level of
dirt in the air cleaner element can
be checked against the indicator.
Replace the air cleaner filter when
the Driver Information Center (DIC)
shows "CHECK AIR FILTER".
7. Damage to Air Intake Ducts and
Hoses : Check for damage of air
intake ducts and hoses and that
those are correctly installed every
24 000 km (15,000 miles) or
12 months. Replace or adjust those
if necessary.
8. Drive Belts : Check belt driving
the fan, alternator or A/C
compressor every 16 000 km
(10,000 miles). Look for cracks,
fraying, wear, and proper tension.
9. Engine Bolt Torques : Loosened
bolts result in lower engine output.
Check and adjust manifold mounting, and injectors to correct
torque every 80 000 km
(50,000 miles).
10. Rotate Tires :
To equalize wear,
rotate tires and adjust tire pressures
every 10 400 km (6,500 miles). See
Tire Rotation 0297.
11. Engine Cooling System : At
12 months or 16 000 km
(10,000 miles) intervals, wash
radiator cap and filler neck with
clean water, pressure test system
and radiator cap for proper pressure
holding capacity, tighten hose
clamps and inspect condition of all
cooling and heater hoses. Replace
hoses if cracked, swollen or
otherwise deteriorated. Have the
hoses replaced by your authorized
dealer.
12. Engine Coolant : Inspect the
engine coolant every 12 months.
Replace the engine coolant every
24 months, drain the engine coolant
by opening the drain plug at the
bottom of the radiator core, flush
and refill the engine cooling system
with a new engine coolant. Refer to
"Preparing Engine Coolant" in

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
Service and Maintenance 327
Engine Coolant0243. Have the
Engine Coolant replaced by your
authorized dealer.
13. Exhaust System : Check the
complete exhaust system every
16 000 km (10,000 miles). Check
body areas near the exhaust
system. Look for broken, damaged,
missing, or out-of-position parts.
Also inspect for open seams, holes,
loose connections, or other
conditions which could cause heat
build-up at the rear body floor pan,
or could let exhaust fumes seep into
the passenger compartment. Dust
or water in the cabin may indicate a
leak in that area. Required repairs
should be made at once.
14. DPF (Clean Filter) : Clean the
filter every 160 000 km
(100,000 miles) or 3,000 hours
whichever occurs first.
15. DPF (Pressure Difference
Sensor 0 Point Adjustment) :
Adjust the sensor every 160 000 km
(100,000 miles) or 3,000 hours
whichever occurs first. 16. DPF (Pressure Difference
Sensor Hose) :
Inspect the sensor
hose every 160 000 km
(100,000 miles) or 3,000 hours
whichever occurs first. Replace the
sensor hose every 400 000 km
(250,000 miles).
17. Fuel Line System : Inspect the
fuel tank, cap and lines for damage
which could cause leakage every
16 000 km (10,000 miles). Inspect
fuel cap for correct sealing ability
and indications of physical damage.
Replace any damaged or
malfunctioning parts.
18. Brake Lining and Pad for
Wear : Check drum brake lining and
disc brake pad for wear or cracks
every 16 000 km (10,000 miles).
Check brakes (including parking
brake) more often if operating
conditions or driving habits result in
frequent braking.
Front disc brakes have built-in wear
noise indicators which are designed
to make a high pitched squeal or
cricket-like warning sound when the
brake pads are worn to the point
where new pads are needed. When the truck is in motion, the
sound may be constant or it may
come and go. Pressing the brake
pedal firmly may cause the sound
to stop.
Have the brake linings or the brake
pads replaced by your authorized
dealer as soon as possible after the
warning first becomes evident.
Failure to do so can result in
expensive damage to the brake
system or a serious crash.
19. Brake Drum and Rotor for
Wear and Damage :
Check brake
drums (rear and parking) and rotors
(front) for wear or damage every
32 000 km (20,000 miles) or
12 months whichever occurs first.
20. Brake Electric Vacuum Pump
(4500HD, 4500XD models) :
Inspect the brake electric vacuum
pump operation every 16 000 km
(10,000 miles) or 12 months,
whichever occurs first.