2019 CHEVROLET LOW CAB FORWARD fuel pressure

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 321
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 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Service and Maintenance 331
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 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
336 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 0307.
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 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Service and Maintenance 337
Engine Coolant0253. 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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Service and Maintenance 341
Recommended Daily
(Pre-operation) Inspections
These checks are in addition to, not
instead of, any legally required daily
inspections. See related topics
under "Maintenance Schedule",
especially if problems are found.
For safe and comfortable driving,
keep record of the distances driven
and the condition of the vehicle
during operation. Perform
inspections at appropriate intervals,
and perform maintenance in
accordance with the findings of the
inspections. If an inspection reveals
an abnormality or there was an
abnormality the previous time the
vehicle was driven, have the vehicle
repaired by the nearest dealer
before it is driven again.1. Components that showed abnormalities during the
previous operation
.Check components that
showed abnormalities
during the previous
operation 2. Checks performed at the
engine
.Fan belt looseness and
damage
. Engine oil level
. Engine coolant level
. Power steering fluid level
3. Checks performed from the driver's seat
.Brake fluid level
. Brake pedal free play
. Operation of meters,
gauges and warning/
indicator lights
. Engine startability,
abnormal noise and color of
exhaust gases
. Parking brake lever stroke
. Windshield washer fluid
spray condition and
windshield wiper
effectiveness
. Windshield washer fluid
level .
Steering wheel position and
free play
. Operation of horn and turn
signal lights
. Door lock operation
4. Checks performed during a walk around the vehicle
.Illumination, flashing,
contamination, damage and
obstruction of lights
. Contamination, damage ad
obstruction of windows,
mirrors and reflectors
. Leaf spring damage
. Oil, engine coolant, fuel,
brake fluid and power
steering fluid leaks
. Water separator
5. Checking wheels and tires .Air pressure
. Cracks and other damage
. Abnormal wear
. Tread depth

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Index 375
DevicesAuxiliary . . . . . . . . . . . . . . . . . . . . . . .117
Diesel Engine Engine Alarm andAutomatic Shutdown . . . . . . . . 173
Diesel Exhaust Fluid . . . . . . . . 24, 189
Diesel Exhaust Fluid (DEF) Gauge . . . . . . . . . . . . . . . . . . . . . . . . . 72
Diesel Exhaust Fluid (DEF) Warning Light . . . . . . . . . . . . . . . . . . 80
Diesel Particulate Filter . . . . . . . . . 180
Distracted Driving . . . . . . . . . . . . . . . 139
Dome Lamps . . . . . . . . . . . . . . . . . . . . 96
Door
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Power Locks . . . . . . . . . . . . . . . . . . . . 33
Drive Belt Routing, Engine . . . . . . 363
Driver Behavior . . . . . . . . . . . . . . . . . 139
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . . . 82
Driving
Emergencies . . . . . . . . . . . . 154, 164
For Better Fuel Economy . . . . . . . 24
Hill and Mountain Roads . . . . . . 150
If the Vehicle is Stuck . . . . . . . . . 153
Wet Roads . . . . . . . . . . . . . . . . . . . 149
Winter . . . . . . . . . . . . . . . . . . . . . . . . 151E
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 236
Electrical System Overload . . . . . . . . . . . . . . . . . . . . . 287
Emergencies . . . . . . . . . . . . . . 154, 164
Engine Air Cleaner/Filter . . . . . . . . . . . . . 253
Alarm and AutomaticShutdown . . . . . . . . . . . . . . . . . . . 173
Check Light (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . 73
Checks Before Operating . . . . . 175
Compartment Overview . . . . . . . 244
Coolant . . . . . . . . . . . . . . . . . . . . . . . 253
Coolant Temperature Gauge . . . . 72
Cover . . . . . . . . . . . . . . . . . . . . . . . . . 245
Drive Belt Routing . . . . . . . . . . . . 363
Exhaust . . . . . . . . . . . . . . . . . . . . . . 177
Heater . . . . . . . . . . . . . . . . . . . . . . . . 172
High Idle System . . . . . . . . . . . . . 174
Oil Pressure Light . . . . . . . . . . . . . . 79
Overheating . . . . . . . . . . . . . . . . . . 259
Reduced Power Light . . . . . . . . . . . 81
Running While Parked . . . . . . . . 179
Shutdown Warning Light . . . . . . . . 80
Engine Oil Level Indicator Light . . . . . . . . . . . . 79 Engines
Diesel Fuel . . . . . . . . . . . . . . . . . . . 227
Exhaust Brake . . . . . . . . . . . . . . . . . . 222
Exhaust Brake Light . . . . . . . . . . . . . 77
Exhaust Fluid Diesel . . . . . . . . . . . . . . . . . . . . . . . . 189
Extender, Seat Belt . . . . . . . . . . . . . . 49
Exterior Lamp Controls . . . . . . . . . . 92
F
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Filter, Engine Air Cleaner . . . . . . . . . . . 253
Fixed Mast Antenna . . . . . . . . . . . . 102
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . 93
Flashers, Hazard Warning . . . . . . . 94
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 310
Fluid Automatic Transmission . . . . . . 251
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 268
Diesel Exhaust . . . . . . . . . . . . . . . . . 24
Power Steering . . . . . . . . . . . . . . . 262
Washer . . . . . . . . . . . . . . . . . . . . . . . 262
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . 370
Front Seat Position Seats Adjustment . . . . . . . . . . . . . . . . . . . . . 38