brake CHEVROLET LOW CAB FORWARD 2020 Manual PDF

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 229
Vehicle Care
General Information
General Information . . . . . . . . . . 230
California Proposition65 Warning . . . . . . . . . . . . . . . . . 230
California Perchlorate Materials Requirements . . . . . 230
Accessories and Modifications . . . . . . . . . . . . . . . . 230
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 231
Cab Tilting . . . . . . . . . . . . . . . . . . . . 233
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 234
Engine Cover . . . . . . . . . . . . . . . . . 235
Engine Oil . . . . . . . . . . . . . . . . . . . . 235
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 241
Engine Air Cleaner/Filter . . . . . . 243
Engine Coolant . . . . . . . . . . . . . . . 243
Engine Overheating . . . . . . . . . . 249
Power Steering Fluid . . . . . . . . . 252
Washer Fluid . . . . . . . . . . . . . . . . . 252
Brakes . . . . . . . . . . . . . . . . . . . . . . . 253
Brake Fluid . . . . . . . . . . . . . . . . . . . 258
Battery - North America . . . . . . 259 Fuel Filter . . . . . . . . . . . . . . . . . . . . 260
Rear Axle (Gear Oil Viscosity
Chart) . . . . . . . . . . . . . . . . . . . . . . . 261
Rear Axle (Oil Level Check) . . . . . . . . . . . . . . . . . . . . . . 262
Noise Control System . . . . . . . . 262
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 264
Wiper Blade Replacement . . . . 265
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 267
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 267
Headlamps and Front Turn Signal . . . . . . . . . . . . . . . . . . . . . . . 270
Roofmarker Lamps . . . . . . . . . . . 274
Sidemarker Lamps (Including Turn Signal and Cornering
Lamps) . . . . . . . . . . . . . . . . . . . . . . 274
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 276
License Plate Lamp . . . . . . . . . . 276
Interior Lamps . . . . . . . . . . . . . . . . 277
Electrical System
Electrical System Overload . . . 277
Wheels and Tires
Wheels and Tires . . . . . . . . . . . . . 285
Tire Pressure . . . . . . . . . . . . . . . . . 297
Tire Rotation . . . . . . . . . . . . . . . . . 297
If a Tire Goes Flat . . . . . . . . . . . . 300
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 301
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 305
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 307
Interior Care . . . . . . . . . . . . . . . . . . 313

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 231
Vehicle Checks
Doing Your Own
Service Work
Precautions for Checking and
Adjustments
Your authorized dealer has trained
technicians and genuine parts to
service your vehicle properly. For
expert advice and quality service,
see your authorized dealer.
{Warning
To help avoid personal injury, take
care when doing any
maintenance or making any
check or repair. Follow
manufacturer's instructions for all
materials used during service and
maintenance of this vehicle.
If used or handled improperly,
they may be hazardous. Improper
or incomplete service can also
affect the vehicle and result in(Continued)
Warning (Continued)
personal injury, or damage to the
vehicle or its equipment. If you
have any questions about
carrying out some service, have
the work done by a skilled
technician.
To prevent personal injury, keep
hands, tools and clothing clear of
the engine cooling fan when the
engine is running.
The engine, exhaust pipe and
radiator will be hot immediately
after the vehicle is driven. Be
careful around these parts to
prevent burns. Perform all checks
when the engine is cold.
Do not perform work near an
open flame or other heat sources.
Do not let the engine run in poorly
ventilated garages or sheds. This
could cause carbon monoxide
poisoning.(Continued)
Warning (Continued)
Performing maintenance work on
a truck or chassis can be
dangerous. In trying to do some
jobs, you can be seriously injured.
Do your own maintenance work
only if you have the required
know-how and the proper tools
and equipment for the job. If you
have any doubts, contact your
dealer.
You and others could be seriously
injured.
Pull firmly on the parking brake
lever and move the selector lever to
"P" and make sure the shift indicator
displays "P".
Make sure to turn off the engine and
remove the key from the engine
control switch before performing any
checks.
Select a place with a solid and level
surface to perform the checking and
maintenance work. Make sure to

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
242 Vehicle Care
For the crew cab vehicle, the
dipstick is located beneath the
rear-of-engine inspection panel.
After unlatching the A/T fluid
inspection cover, the dipstick will be
visible.
Inspection
Wait at least 30 minutes before
checking the transmission fluid if
you have been driving at high speed
for a long period of time, in city/
heavy traffic or while pulling a trailer.1. Start the engine, and drive the vehicle for approximately
10 minutes to warm up the
engine. During 10 minutes, the automatic transmission fluid
should reach a temperature of
approximately 70 - 80 °C (158 -
176 °F). During the winter
when temperatures are low,
adjust the amount of driving
time according to the actual
conditions.
2. Park the vehicle on level ground, and firmly apply the
parking brake.
3. With the engine idling, move the selector lever from the “P”
position to the “1”position
while pressing the brake pedal,
and then return the lever from
the “1”position to the “P”
position.
4. With the engine still idling, pull out the dipstick and wipe it with
a clean cloth.Transmission Dipstick
5. Reinsert the dipstick into position, pull out the dipstick
slowly, and check whether the
fluid level is within the “H”
marked range. Always check
the fluid level at least twice.
Consistently is important in
maintaining accuracy.
If inconsistent readings persist,
check the transmission
breather to ensure that it is
clean and free of debris.
. Dipstick C (COLD) —
Transmission fluid
temperature Approx. 20 -
30 °C (68 - 86 °F).

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 253
properly wiped. At this time, also
check the spraying condition of the
windshield washer.
Inspect the washer fluid level
regularly, especially during bad
weather conditions.
Use a high quality premixed solvent
available at most dealers or service
stations.
Avoid hard water when mixing
windshield washer solvents. Hard
water contaminants may plug
orifices in the washer system and
reduce performance.
Do not use radiator antifreeze in the
windshield washer; it could cause
cab paint damage.
In cold weather, warm the
windshield with the defrosters
before using the washer, to help
prevent icing that may block the
driver's vision.Refilling Windshield Washer
Fluid
1. The windshield washer fluidtank (1) is located under the
instrument panel on the
passenger side.
2. Open the cap (2) and fill the tank with windshield washer
fluid.
Upon factory shipment, new
vehicles contain only tap water in
the washer fluid tank. Adjust the
concentration of the fluid to suit your
own usage. Follow the instructions provided with
the windshield washer fluid
regarding the ratio for mixing with
tap water.
Poor quality products, engine
coolant, and soapy water must not
be used. Failure to observe this
precaution can result in nozzle
blockage or damage to painted
surfaces.
The washer should never be used
while the tank is empty. Operating
the washer with the tank empty can
result in motor damage.Brakes
For the most effective braking and
for maximum life from brake system
components, follow these
suggestions:
.
Keep any obstructions from
interfering with brake pedal
travel.
. Keep tires properly inflated.
Improperly inflated tires can
reduce the efficiency of the
brakes.

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
254 Vehicle Care
Follow the recommendations for
brake checks in the Maintenance
Schedule.
GM replacement brake lining
material is recommended for this
vehicle to maintain the balance
between front and rear brake
performance. GM replacement
brake parts have been carefully
selected to provide the proper brake
balance for purposes of both
stopping distance and controllability
over the full range of operating
conditions. Installation of front or
rear brake lining material with
performance different from that of
the replacement parts
recommended for this vehicle can
change the intended brake balance
of this vehicle.
Checking the Brake Electric
Vacuum Pump (4500HD/
4500XD Series)
1. Turn the engine control switchto the "ON" position (do not
start the engine), and press the
brake pedal several times. 2. Check for the noisy sound of
the electric vacuum pump
inside the instrument panel at
the same time as vacuum
warning buzzer sound, and
check that the brake low
vacuum warning light
comes on.
3. Then, start the engine. The main vacuum pump driven by
the engine will start running.
If the electric vacuum pump
operation (noisy sound) and
the vacuum warning buzzer
stop, and the brake low
vacuum warning light goes off
thereafter, the operation is
normal.
4. If you cannot hear the noisy sound or the noisy sound stays
on all the time, have the
vehicle inspected by the
nearest dealer immediately.Hydraulic Brake Booster (HBB)
The 5500HD, 5500XD models are
equipped with an HBB system. HBB
is a brake booster device that utilizes hydraulic pressure from the
HBB pump integral with the power
steering pump.
If the brake booster warning light
comes on or a warning buzzer
continues to sound, there may be a
problem with the HBB.
If this warning light comes on while
driving, immediately stop your
vehicle at a safe place well clear of
traffic and promptly contact the
nearest dealer for inspection.
Hydraulic brake booster (HBB)
characteristics
In the 5500HD, 5500XD models, an
unusual sound from under the
instrument panel may be heard from
the hydraulic system while brakes
are used. It does not mean trouble.
It is not a sign of malfunction.
If you pump the brakes with the
engine off, a squeaking sound can
be heard. This comes from the
auxiliary accumulator. It is not a
malfunction. With the engine
running, a similar sound can be
heard during sudden braking.

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 255
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 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
256 Vehicle Care
lead to dragging brakes or other
major brake problems. As such,
mixing of these two fluids can
ultimately lead to vehicle fire or
other serious crashes.
When the pump operates while the
engine is running, the fluid in the
hydro-booster will become hot.
During normal braking, the
temperature in piping and within the
hydro-booster can rise above
100 °C (212 °F). For this reason,
special care will be required when
working with hydro-booster
components. If the hydro-booster is
to be removed from the vehicle,
shut off the engine and then allow at
least 30 minutes for it to cool down
before beginning this operation.
Even when the engine is stopped,
the hydro-booster's accumulator will
remain in a highly-pressurized
condition for a significant period of
time. Before removing the
hydro-booster or piping from the
vehicle, stop the engine and press
the brake pedal at least 10 times in
order to lower the accumulator
pressure to atmospheric pressure.This is of particular importance
when removing components such
as the accumulator or pressure
switch from the hydro-booster.
If these operations are attempted
while the accumulator is still at a
high pressure, hydro-booster fluid
may spray out.
Checking the Hydro-booster Fluid
Level
Check the hydro-booster fluid level
and change the fluid according to
the Maintenance Schedule.
The hydro-booster fluid level is
correct if it is between the "MAX"
and "MIN" lines. If the level is too
low, add fluid up to the "MAX" line.
Be sure to use Dexron VI ATF fluid
when adding fluid. The brake
booster reservoir is located behind
the cab on the left side.
Brake Pedal
Stroke
Shut off the engine and press the
brake pedal about 10 times strongly,
then check the brake pedal for free
play by lightly pushing it by hand
until you feel resistance.

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 257
Free play (measured at the tip ofpedal)
5 - 10 mm (0.20 - 0.39 in) (4500HD/4500XD)
24 - 29 mm (0.95 - 1.14 in) (5500HD/5500XD)
1. Clearance from the floor.
2. Brake pedal bracket.
Next, start the engine, and wait at
least 1 minute. Then press the
brake pedal and measure the
clearance (1) of the pedal from the floor (that is, the distance between
the brake pedal bracket (2) and the
brake pedal arm).
Clearance between the brake
pedal and the brake pedal bracket with a pressure of 490 N (110 lbs)
applied to the brake pedal
35 mm (1.38 in) or more (4500HD/ 4500XD)
Clearance between the brake
pedal and the brake pedal bracket with a pressure of 294 N (66 lbs) applied to the brake pedal
35 mm (1.38 in) or more (4500HD/ 4500XD/5500HD/5500XD)
If, after continued pressing of the
brake pedal, the clearance slowly
decreases or the pedal action feels
spongy, air may be trapped in the
brake hydraulic circuit. Have your
vehicle inspected at the nearest
dealer as soon as possible.
If your vehicle's brakes squeak
during normal driving or braking, the
cause may be one of the following. ‐
Brake pad wear
Brake pads are about to wear
out. If this happens, have your
vehicle inspected at the nearest
dealer as soon as possible.
‐ Adherence of sand, grit or mud
If sand, grit or mud adheres to
the brakes, a screeching sound
may be emitted upon contact with
rotating components. If this
happens, wash the vehicle to
remove all such adhering matter.
If cleaning alone does not
eliminate the squeaking sound,
have your vehicle inspected at
the nearest dealer.
Brake Hoses and Pipes
Inspection
With the steering wheel turned fully
to the left, check the left front brake
hose and pipe visually and by
touch, making sure that they are
free of scratches, cracks and
bulging. Also make sure that the
hose and pipe do not interfere with
any chassis part or wheel, and that
their joints are not leaking and are