low oil pressure CHEVROLET LOW CAB FORWARD 2019 User Guide

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 265
Another characteristic of the HBB
system is that the brake pedal may
be pressed easily to the floor with
the vehicle at a stop. This is not a
sign of malfunction.
When the engine is running, the
system automatically charges the
accumulator whenever pressure has
been reduced after braking. Auto
charge may be activated without
braking, depending on temperature
changes in the accumulator. During
auto charge, a hissing and clicking
sound can be heard. This is not a
malfunction.
With the engine running, a booming
sound can be heard during hard
braking. This comes from the
brake-fluid pump. It is not a
malfunction.
Applying continuous hard braking
for a long time will lead to
considerable temperature rise in the
HBB pump. Such overworking of the
brakes is best avoided.Vacuum or hydraulic power
assisted brakes
If the engine stops, do not pump the
brakes. The system is designed to
stop the vehicle with reserve power
assist if the brake pedal is held
down. This reserve is greatly
reduced each time you apply and
release the brakes. If, when you
turn the steering wheel during
braking, the vehicle does not turn,
release some pressure from the
brake pedal.
In a Vehicle Equipped with an
HBB, Do Not Keep the Brake
Pedal Pressed for an Extended
Period
Caution
Failure to follow the above
instruction will cause the oil inside
the HBB oil pump to get very hot.
This could damage the HBB tank
and deteriorate seals and also
could cause damage to the HBB
oil pump, HBB unit and/or HBB
(Continued)
Caution (Continued)
hosing. Eventual leakage of HBB
oil, sudden increase in brake
pedal resistance and fire could
unexpectedly result in a crash.
Hydraulic Brake Booster (HBB)
Fluid (5500HD/5500XD Series)
The HBB system has been
designed to use Dexron VI ATF
fluid. If any other fluid is used with
this system, rubber components
may be damaged, oil may leak and
the system may malfunction. It is
important to remember that the fluid
used in the hydro-booster is
completely different in
characteristics from the brake fluid
used in the master and wheel
cylinders.
If hydro-booster fluid and brake fluid
from the master cylinder are
mistakenly mixed together and
used, rubber components will
deteriorate as a result of insufficient
lubrication. Any resultant oil leakage
or system malfunction can in turn

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 295
{Warning
Always use fuses specified by the
dealer when replacing the
slow-blow fuse. Using fuses with
a rating other than that specified,
or using wire or tin foil, etc., could
result in fire or damage.
If the new fuses blow right away
and the cause is unknown,
contact your dealer.
Do not inspect or replace fuses
when the starter switch is in the
ON position. Doing so may lead
to an accident.
When inspecting fuses, be sure to
park the vehicle on flat, level
ground and apply chocks to the
wheels.It is not necessary to open or close
the cover unless trouble is found.
The relay box structure makes it
difficult for water to enter. If you
should spill water or a beverage of
the cover, however, wipe it off
before opening the cover.
The area around the cover will get
warm when the vehicle is being
driven, but this is not abnormal.
Wheels and Tires
The operating load and cold inflation
pressure on the rim and wheel must
not exceed the rim and wheel
manufacturer's recommendations
even though the tire may be
approved for a higher load or
inflation. Rim and wheel may be
identified (stamped) with maximum
load and maximum cold inflation
rating. For rims and wheels not so
identified or for service conditions
exceeding the rate capacities,
consult the rim and wheel
manufacturer to determine rim and
wheel capacities for the intended
service. The factory-installed tires
on this vehicle were selected to
provide the best all-around tire
performance for normal operation.
When inflated, as shown on the
vehicle, they have the load carrying
capacity to operate satisfactorily at
all loads up to and including the full
rated load specified for the vehicle.
For more information concerning the
differences in capacities of tires and

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 305
Danger (Continued)
.Note that taking off and
mounting tires on wheels
requires proper tools, safety
equipment and special
training. A person can be
severely injured or killed
and damage can result from
using the wrong service
methods. Truck tires and
wheels should be serviced
only by trained people using
the proper equipment.
. Never add air to your tires
unless an accurate pressure
gauge is also used. When
putting air in a tire on the
vehicle, stand to the side
and use a clip-on chuck and
hose extension. In choosing
the right tire pressure, be
careful not to exceed the
maximum pressure
capability shown on the tire;
see the tire pressure charts
in this manual.
(Continued)
Danger (Continued)
.Tire mounting or repair can
result in serious personal
injury or death, if not
performed correctly. This
section has detailed
instructions for proper wheel
and tire replacement, so be
sure to read and follow
them. Truck fleet owners
and operators: You can get
written instructions on truck
tire demounting, repair and
mounting from Rubber
Manufacturers Association
(RMA), 1400 K Street N.W.,
Washington, D.C. 20005,
and also from many tire
stores. Wheel Nut Torque{Warning
Never use oil or grease on studs
or nuts. Use the torque specified
for the type of wheels on the
vehicle. Snug all wheel nuts and
then tighten to the specified
torque in the numerical sequence
shown. Improperly tightened
wheel nuts could eventually allow
the wheel to come off while the
vehicle is moving, possibly
causing loss of control and
personal injury and property
damage.
When the vehicle, wheel or
fasteners are new, have a
technician tighten wheel stud nuts
and rim clamp nuts with a torque
wrench at 1 040 km (650 mi). This is
necessary because the clamping
system used on the wheels must
seat before the fastener will hold a
uniform clamp load and remain fully
tightened. Also have a technician

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 317
3. No vehicle should ever betowed over 88 km/h (55 mph).
4. Loose or protruding parts of damaged vehicles should be
secured prior to moving.
5. A safety chain system completely independent of the
primary lifting and towing
attachment must be used.
6. Operators should refrain from going under a vehicle which is
being lifted by the towing
equipment unless the vehicle is
adequately supported by safety
stands.
7. No towing operation which for any reason jeopardizes the
safety of the wrecker operator
or any bystanders or other
motorists should be attempted.Appearance Care
Exterior Care
Exterior Finish
The paint finish on your vehicle
provides beauty, depth of color,
gloss retention and durability.
While cleaning the vehicle, do not
grip the roof marker lights to prevent
damage or water leakage.
Washing
The best way to preserve your
vehicle's finish is to keep it clean by
washing it often.
Wash the vehicle in lukewarm or
cold water. Do not use hot water or
wash your vehicle in the direct rays
of the sun. Do not use strong soap
or chemical detergents. All cleaning
agents should be flushed promptly
from the surface and not allowed to
dry on the finish.
These vehicles are designed to
operate under normal environmental
conditions to withstand natural
elements. However, unusual conditions such as high-pressure
car washers may cause water to
enter inside the vehicle. If the
vehicle is operated with foreign
material adhering to the exterior,
this material may react chemically
with paint, resulting in staining,
discoloration, rusting or corrosion of
components. Also, the material may
become trapped within mechanical
components, adversely affecting
their functions or forming an
aerodynamic resistance. In the
following cases, therefore, the
vehicle must be washed and all
foreign matter removed.
.
When soot, iron powder, dead
bugs, bird droppings, tree sap or
oily matter from coal tar and
smoke has adhered to painted
surfaces.
. When the vehicle has been
driven in coastal areas.
. When the vehicle has been
driven on roads where road
chemicals have been applied.
. When a large amount of mud or
dirt has adhered to the exterior.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 325
.Follow specific instructions on
cleaner labels.
General Cleaning of Soiled or
Water Spotted Fabric Type
Trim with Foam Type Cleaner
Vacuum the area thoroughly to
remove any loose dirt.
Always clean a whole trim panel or
section. Mask surrounding trim
along stitch or welt lines.
Use suds on a clean sponge. Do
not brush wet suede. Do not
saturate the material or rub it
harshly. Immediately after cleaning,
remove suds with a sponge and
rinse with a clean wet sponge. Wipe
off remaining residue with a slightly
damp absorbent towel or cloth.
Immediately after wiping, force-dry
the fabric with an air hose. A heat
dryer or heat lamp may be used.
Use caution with a heat dryer or
lamp to help prevent damage.
When trim materials with a sheen or
luster finish are dry, wipe the fabric
lightly with a soft, dry, clean cloth to
restore its sheen or luster. For suede, raise nap with a dry scrub
brush and vacuum to remove any
final traces of residue.
Spot Cleaning Fabric Type
Trim with Solvent Type Cleaner
Before trying to remove a spot or
stain from fabric, try to find out the
type and age of the spot or stain.
Some spots or stains can be
removed with water or a mild soap
solution. Spots or stains should
always be removed as soon as
possible.
Some types of stains or soilage,
such as lipstick, inks, and grease,
are very difficult (sometimes
impossible) to remove completely.
When cleaning this type of stain or
soilage, be sure not to enlarge the
soiled area.
.
Gently scrape excess stain from
the trim material with a clean,
dull knife or scraper. Use very
little cleaner, light pressure, and
clean cloths, preferably
cheesecloth. Cleaning should
start at the outside of the stain feathering towards the center.
Keep changing to a clean
section of cloth.
. When you clean a stain from
fabric, immediately dry the area
with an air hose, heat dryer,
or heat lamp to help prevent a
cleaning ring. Use caution with
heat dryer or lamp to help
prevent fabric damage.
. If a ring forms, immediately
repeat the cleaning operation
over a slightly larger area with
emphasis on feathering towards
its center. If a ring still remains,
mask off surrounding trim
sections and clean the entire
soiled area with a foam type
cleaner.
See “Removal of Specific
Stains.”
Removal of Specific Stains
Greasy or Oily Stains –Includes
grease, oil, butter, margarine, shoe
polish, coffee with cream, chewing
gum, cosmetic creams, vegetable
oils, wax crayon, tar, and asphalts.

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 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
Technical Data 359
Service SpecificationsWeights
Axle weight rating : Front 4500HD: 2431 kg (5,360 lb) 4500XD: 3007 kg (6,630 lb)
5500HD: 3098 kg (6,830 lb) 5500XD: 3300 kg (7,275 lb)
Engine Oil
Engine oil capacity When changing oil and filter: 11.0 L (11.6 qt)
*1
Engine Cooling System
Capacity 19.6 L (20.7 qt)
Engine oil Thermostat:
Starts to open 82–85 °C (180–185 °F)
Radiator pressure 108 kPa (16 psi) Transmission
Transmission oil capacity 13.1 L (27.7 pt)
*3
Rear Axle
Differential gear oil
capacity 4500HD/4500XD:
9.0 L (19.0 pt)
*4
5500HD/5500XD:10.0 L (21.1 pt)*4

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

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Index 377
Lamps (cont'd)License Plate . . . . . . . . . . . . . . . . . 286
Malfunction Indicator (Check
Engine) . . . . . . . . . . . . . . . . . . . . . . . 73
Roofmarker . . . . . . . . . . . . . . . . . . . 284
Sidemarker . . . . . . . . . . . . . . . . . . . 284
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . . . 48
Lighting Illumination Control . . . . . . . . . . . . . 95
Lights Antilock Brake System(ABS) Warning . . . . . . . . . . . . . . . . 76
Automatic Transmission Fluid Temperature . . . . . . . . . . . . . 78
Battery Warning . . . . . . . . . . . . . . . . 73
Brake System Warning . . . . . . . . . 74
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . 73
Cruise Control . . . . . . . . . . . . . . . . . . 82
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 81
Diesel Exhaust Fluid (DEF) . . . . . 80
Engine Oil Level Indicator . . . . . . 79
Engine Oil Pressure . . . . . . . . . . . . 79
Engine Shutdown Warning . . . . . 80
Exhaust Brake . . . . . . . . . . . . . . . . . . 77
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 93
High-Beam On . . . . . . . . . . . . . . . . . . 81 Lights (cont'd)
High/Low Beam Changer . . . . . . . 93
Idle Shutdown . . . . . . . . . . . . . . . . . . 80
Overdrive Off . . . . . . . . . . . . . . . . . . . 78
Reduced Engine Power . . . . . . . . 81
Seat Belt Reminders . . . . . . . . . . . . 72
Service Transmission
Warning . . . . . . . . . . . . . . . . . . . . . . . 77
Service Vehicle Soon . . . . . . . . . . . 74
Wait to Start . . . . . . . . . . . . . . . . . . . . 79
Loading the Vehicle . . . . . . . . . . . . . . 58
Locks Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Power Door . . . . . . . . . . . . . . . . . . . . . 33
M
Maintenance and CareAdditional . . . . . . . . . . . . . . . . . . . . . 346
Maintenance Schedule . . . . . . . . . 327
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . 349
Malfunction Indicator Lamp . . . . . . 73
Messages Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . 86
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Heated . . . . . . . . . . . . . . . . . . . . . . . . . 34
N
New Vehicle Break-In . . . . . . . . . . . 165
Noise Control System . . . . . . . . . . 272
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . . 70Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . 245
Pressure Light . . . . . . . . . . . . . . . . . . 79
Online Owner Center . . . . . . . . . . . 365
Operating Temperature . . . . . . . . . 171
Outlets
Power . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Overdrive Off . . . . . . . . . . . . . . . . . . . 215
Overdrive Off Light . . . . . . . . . . . . . . 78
Overheating, Engine . . . . . . . . . . . . 259
Owner Checks and Services . . . . 340
P
Parking
Brake . . . . . . . . . . . . . . . . . . . . . . . . . 220
Over Things That Burn . . . . . . . 176
Passenger Compartment Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Pedals . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Perchlorate Materials Requirements, California . . . . . . 240