check engine 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
Vehicle Care 297
Tire Pressure
Tire Load and Inflation Table
Tire Load and Inflation Table
TIRES FOR VEHICLES IN HIGHWAY SERVICE
TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES
Tire Size Designation Cold Inflation Pressure (psi) 50 55 60 65 70 75 80 85 90 95
LT215/85R16E Dual Single(lbs) 2470
2680
225/70R19.5F Dual Single(lbs) 3115
33153245
34503415
3640
See Wheels and Tires 0285.
Tire Rotation
{Warning
Be sure to check the wheel studs,
wheel nuts and disc wheel for any
abnormality whenever the disc
wheel is removed.
(Continued)
Warning (Continued)
If you find any abnormal condition
on the wheel studs, wheel nuts or
disc wheel, do not continue to use
the wheel. Contact the nearest
dealer as soon as possible
Tires at different locations wear
differently. For uniform tire wear and
longer tire life, you should rotate the
tires on your vehicle regularly. Make sure to use tires of the same type
on the same axle. If you install tires
of different types on the same axle,
the vehicle may drift right or left
when you apply the brakes.
New tires are more likely to build up
heat and wear faster than old tires,
so they should be installed on the
front axle where the load is smaller.
If there is a difference in diameter
between the inner and outer tires of
a dual-tire wheel, install the smaller
diameter tire inside.

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
298 Vehicle Care
The difference in diameter of the
tires for a dual-tire wheel should be
within the limit specified in the table
below. If the limit is exceeded, the
tires wear more rapidly than they
should.
{Warning
If tires of different sizes, load
ranges, constructions, or tread
designs are used between the
front and rear axles, do not
exchange tires between the front
and rear axles; otherwise, the(Continued)
Warning (Continued)
tires may get loaded beyond their
limits. This will also affect vehicle
handling, brake performance, and
ride comfort. This is highly
dangerous because the tires and
disc wheels could break down
under an excessive load. You and
others could be seriously injured.
Permissible diameter difference
Radial tire Within 8 mm (0.31 in)
The tightening torque of the wheel
nuts may decrease after a tire
change due to their initial
settlement. Upon driving 50 to
100 km (31 to 62 mi) after a tire
change, retighten the wheel nuts to
the specified torques according to
the instructions in "Retightening
Wheel Nuts" following.
See Maintenance Schedule 0317.
Retightening Wheel Nuts
Check the wheel nuts to make sure
they are tightened to the specific
torque by using a torque wrench.
Use the following methods to check
loose wheel nuts. The tightening
torque of the wheel nuts may
decrease after a tire change or
rotation due to their initial
settlement. After driving 1 040 km
(650 mi) and after 10 400 km
(6,500 mi), be sure to retighten the
wheel nuts to the specified torque.
Repeat whenever a wheel, wheel
bolt, or wheel nut is removed.
Tightening torque
500 N·m (362 lb·ft)

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
300 Vehicle Care
3. Next, tighten the outer wheelnuts to the specified torque.
{Warning
If you find any abnormal
conditions with the wheel nuts
such as frequent loosening of
retightened nuts, have your
vehicle checked or serviced at the
nearest dealer as soon as
possible.
Fully engage the wheel wrench on a
wheel nut in order to tighten the nut
to the specified torque. However, do
not use a pipe as a handle
extension or your foot to apply force
on the wrench. This would tighten
the nut more than required and
might damage components.
Both under-tightening and
over-tightening of wheel nuts may
cause broken wheel studs or
cracked disc wheels and could lead
to wheel detachment. Adhere to the
specified tightening torques. When replacing a tire with a new
one, use only a tire of the same
type and size as the replaced tire;
otherwise, driving safety could be
affected. Avoid mixed use of
different types or different size tires
at all costs.
If a Tire Goes Flat
When the tire goes flat while driving,
ease off the accelerator pedal, avoid
hard braking, hold on to the steering
wheel firmly, and stop the vehicle.
The tire should be changed in a
safe, open location to prevent
obstructing other vehicles or
pedestrians.
{Warning
If you continue to drive on a flat
tire, undue force will be applied to
the wheel studs, possibly causing
the studs to break and the wheel
to come off. You and others could
be seriously injured.
See “Tire Replacement
Recommendations” underWheels
and Tires 0285.

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
306 Vehicle Care
Front End Towing (All Wheels On
the Ground)
Your vehicle may be towed on all
wheels provided the steering is
operable. Remember that power
steering and brakes will not have
power assist. There must be a tow
bar installed between the tow
vehicle and the disabled vehicle.
Towing with all wheels on theground
1. Bumper
2. Tow Hook
3. Front Axle
4. Towing Guide
5. Towing Chain
To prepare a disabled vehicle for
front end towing with all wheels on
the ground, the following steps are
necessary:
.Block the rear wheels of the
disabled vehicle.
. Disconnect the driveshaft at the
rear axle. Secure the driveshaft
to the frame or crossmember.
When towing, disconnect the
driveshaft at the rear axle to ensure
the transmission is not damaged.
The rear end of the driveshaft must
be disconnected and safely secured
if the 80 km (50 mi) or 48 km/h
(30 mph) is exceeded.
Provide wood blocking to prevent
towing chains and bar from coming
into contact with the bumper.
If there is damage or suspected
damage to the rear axle, remove the
axle shafts.
Cover the hub openings to prevent
the loss of lubricant or entry of dirt
or foreign objects. After Towing
After towing the vehicle, block the
rear wheels and install axle shafts
or driveshaft.
Apply the parking brake before
disconnecting from the towing
vehicle. Check and fill rear axle with
oil, if required.
Rear End Towing
When towing a vehicle with rear
wheels raised, secure the steering
wheel to maintain straight-ahead
position. Make certain that the front
axle is not loaded beyond the front
axle gross axle weight rating
(GAWR) as indicated on the
vehicle's VIN and weight rating
plate.
Special Towing Instructions
1. All state and local laws regarding such items as
warning signals, night
illumination, speed, etc., must
be followed.
2. Safety chains must be used.

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 317
Service and
Maintenance
Maintenance Schedule
Maintenance Schedule . . . . . . . 317
Owner Checks and Services
Owner Checks andServices . . . . . . . . . . . . . . . . . . . . 330
Additional Maintenance
and Care
Additional Maintenanceand Care . . . . . . . . . . . . . . . . . . . . 336
Recommended Fluids,
Lubricants, and Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . 339
Maintenance Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . 341
Maintenance
Schedule
Caution
Damage caused by improper
maintenance can lead to costly
repairs and may not be covered
by the vehicle warranty.
Maintenance intervals, checks,
inspections, recommended fluids,
and lubricants are important to
keep the vehicle in good working
condition.
Do not have chemical flushes that
are not approved by GM
performed on the vehicle. The
use of flushes, solvents, cleaners,
or lubricants that are not
approved by GM could damage
the vehicle, requiring expensive
repairs that are not covered by
the vehicle warranty.
Make sure the vehicle is inspected
at regular intervals. Inspections and
maintenance enable you to use the vehicle with peace of mind. They
also extend the vehicle's
service life.
For safe and economical driving, we
recommend that you have your
vehicle inspected and serviced
regularly according to the schedule
indicated in this chapter.
To drive your vehicle safely and at
minimum cost, it is essential to have
your vehicle regularly inspected and
serviced at your dealer as per the
specified maintenance schedule.
Contact your dealer for inspection
that requires disassembly and/or
special equipment.
The Maintenance Schedule in this
manual and a Warranty Information
Booklet are supplied with your
vehicle. Read all publications for a
full understanding of your vehicle's
maintenance needs.
The quality of maintenance your
new vehicle receives is as important
as the regularity with which it is
serviced. Authorized dealers provide
nationwide quality in customer
service. The program includes the

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 319
.Frequent short trips of less than
16 kilometers (10 miles) in sub-
freezing temperatures
. Frequent and extended low-
speed engine operation (door-
to- door deliveries, stop- and- go
traffic, etc.)
. Driving on unpaved roads with
heavy dust
. Towing a trailer
Power Take Off (PTO) and
Extended Idle Use
When the vehicle is used with the
PTO equipment or used in a way
that requires extended idle time,
one hour of use shall be deemed
the same as 33 miles. See Driver
Information Center (DIC) 070 for
hourmeter.
Preventive Maintenance
As any mechanical device operates,
a certain amount of wear occurs.
The amount of wear depends on
certain variables –type and method
of operation and the schedule of
maintenance. These variables may be emphasized as critical to
malfunction but each is dependent
upon the other. For example, if a
vehicle is repeatedly overloaded,
driven at excessive speed or
improperly shifted, no schedule of
maintenance can prevent
malfunction. Also, if a preventive
maintenance schedule is not
followed, or is improperly carried
out, no amount of correct vehicle
operation will prevent malfunction.
If vehicle application, operation and
preventive maintenance schedules
and procedures are followed and
properly carried out, the life of the
vehicle will be greatly extended.
For example, regular attention to the
engine oil is essential. The oil level
must be periodically checked and oil
added whenever needed. Also, the
oil should be changed at the
intervals specified with the proper
quality and viscosity of oil. If your
engine should run excessively low
on oil or if the oil has lost its
lubricating qualities because of old
age, serious engine damage could
occur.
Maintenance Schedule Table
Letters Used to Indicate
Maintenance Service Types
I :
Inspect then clean, repair or
replace as necessary
A : Adjust
R : Replace
T : Tighten to the specified torque
L : Lubricate
C : Clean

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 325
maintenance intervals and may
cause a problem with engine
durability.
(3)Refer to "Air Cleaner Indicator
Light" under Engine Air Cleaner/
Filter 0243.
(4) Initial check at 1 040 km
(650 miles) is required.
(5) Be sure to discard used grease
seal, and always use new grease
seal for installation.
Explanation of Complete
Vehicle Maintenance Schedule
The following is a brief explanation
of each of the services listed in the
preceding Complete Vehicle
Maintenance Schedule.
1. Engine Noise : These
components have an effect on the
control of noise emissions. Service Interval Maintenance procedure
Engine
Every 16 000 km (10,000 miles) Inspect sound absorption materials for
tears, broken out sections or
attachment. Repair or replace as
necessary.
Cooling System
Every 16 000 km (10,000 miles) Inspect fan, shroud and radiator for
attachment, tears or cleanliness.
Replace as necessary.
Air intake system
Every 24 000 km (1,500 miles) Inspect all ducts, hoses and intake
silencers for leaks or chafing. Repair or
replace as necessary.
Exhaust system
Every 16 000 km (10,000 miles) Inspect silencer, pipes, gaskets, clamps
and mounting for exhaust gas leaks or
looseness. Repair or replace as
necessary.
Cab
Every 16 000 km (10,000 miles) Inspect sound absorption materials for
tears, broken out sections or
attachment. Repair or replace as
necessary.
2. Valve Lash : Incorrect valve
clearance will result in increased
engine noise and lower engine
output, thereby adversely affecting
engine performance. Retorque rocker shaft bracket nuts before
checking and adjusting valve
clearance.
Check and adjust valve clearance
every 80 000 km (50,000 miles) or
12 months whichever occurs first.

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.