maintenance schedule CHEVROLET LOW CAB FORWARD 2020 User Guide

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
252 Vehicle Care
Power Steering Fluid
The power steering fluid level must
be checked and it must be changed
according to the Maintenance
Schedule. SeeMaintenance
Schedule 0317.
When replenishing power steering
fluid or flushing the power steering
system, always use ATF
(Dexron
®-VI). Failure to use the
proper fluid may damage the power
steering system seals and hoses,
leading to fluid leakage.
Checking the Power Steering
Fluid Level
The fluid level is correct if it is
between the “MAX”and“MIN” lines
on the power steering fluid tank.
If the level is lower that the “MIN”
line, add fluid up to the “MAX”line.
The reserve tank is located at the
rear of the engine compartment on
the right. When you have finished
checking the fluid level, securely
reinstall the cap and cover.
{Warning
Before adding fluid, clean the
area around the cap and pour
fluid from a clean jug or filler.
Foreign matter getting in the tank
may cause power steering system
failure.
Do not mix the recommended
power steering fluid with fluids of
other brands. Due to chemical
reactions, any mixture of
differently branded fluids may
cause failure of the system.
You and others could be seriously
injured.
Washer Fluid
Windshield Washer Fluid
The windshield washer is equipped
on the windshield wiper arm.
Check the level of fluid in the
windshield washer fluid tank. In
addition, spray windshield washer
fluid and operate the windshield
wipers to check for any areas not

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
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
258 Vehicle Care
free of any type of damage. Check
the right front brake hose and pipe
in the same way. The rear left and
right brake hoses and pipes should
also be checked in the same
manner.
Disc Brakes and Drum Brakes
If the brake pads and shoe linings
wear out beyond their usable limit,
not only will the brake performance
be impaired, but brake components
could also fail.
{Warning
Do not drive with brake pads and
shoe linings worn out beyond the
limit. Excessively worn brake
pads and shoe linings may cause
breakdown of brake components
and poor braking performance.
You and others could be seriously
injured.
Caution
The pad has an embedded wear
indicator. A squeaking noise from
the indicator means that the pad
is approaching the usable limit.
If the squeaking noise from the
indicator can be heard, contact
the nearest dealer for inspection
or replacement.
Brake Fluid
Checking the Brake Fluid
Level
Remove the inspection cover (1) on
the left- hand side of the instrument
panel by turning it with your fingers.
Check that the fluid level in the
reservoir is between the "MAX" and
"ADD" lines.
If the fluid surface cannot easily be
seen, rock the vehicle gently.
Adding Brake Fluid
If the level of brake fluid has
dropped below the "ADD" line,
remove the cap (2) and add fluid.
Take care to avoid filling beyond the
"MAX" line.
Tighten the cap securely after the
fluid has been added.
When adding brake fluid to the tank,
take care to prevent dirt and water
from entering it. Any dirt or water in
the system could cause the vehicle
to lose braking functions.
Inspect and change brake fluid
according to the Maintenance
Schedule.
Use the recommended brake fluid
when adding brake fluid.

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
262 Vehicle Care
Rear Axle (Oil Level
Check)
Rear Axle Differential Gear Oil
The rear axle differential gear oil
level must be checked for its level
and it must be changed according to
the Maintenance Schedule.
Use the oil quantities indicated later
in this section only as guidelines
when changing the rear axle
differential gear oil.
After changing the oil, ensure that it
is at the correct level.
Drained oil must be disposed of in a
method conforming to the regulatory
requirements in your state.Checking the Oil Level
1. Remove the oil level plug.
2. Check that the oil level (1) is
0 mm to 10 mm (0 to 0.4 in)
below the bottom edge of the
oil level plug hole (2). If the oil
level is too low, add oil through
the oil level plug hole.
3. Fasten the oil level plug to the specified torque. Plug
tightening torque is 84 Nm
(8.6 kgFm/62 lb ft).
Any dirt on the plug should be
wiped off before installing it.
Noise Control System
Noise Emissions Warranty
General Motors warrants to the first
person who purchases this vehicle
for purposes other than resale and
to each subsequent purchaser that
this vehicle as manufactured by
General Motors, was designed, built
and equipped to conform at the time
it left General Motors’ s control with
all applicable U.S. EPA Noise
Control Regulations. This warranty
covers this vehicle as designed,
built and equipped by General
Motors, and is not limited to any

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 263
particular part, component or
system of the vehicle manufactured
by General Motors. Defects in
design, assembly or in any part,
component or system of the vehicle
as manufactured by General
Motors, which, at the time it left
General Motors’s control, caused
noise emissions to exceed Federal
standards, are covered by this
warranty for the life of the vehicle.
The following information relates to
compliance with federal noise
emission standards for vehicles with
a Gross Vehicle Weight Rating
(GVWR) of more than 4 536 kg
(10,000 lb). The Maintenance
Schedule provides information on
maintaining the noise control system
to minimize degradation of the noise
emission control system during the
life of the vehicle. The noise control
system warranty is given in the
warranty manual.
These standards apply only to
vehicles sold in the United States.TAMPERING WITH NOISE
CONTROL SYSTEM
PROHIBITED
Federal law prohibits the following
acts or the causing thereof:1. The removal or rendering inoperative by any person,
other than for purposes of
maintenance, repair,
or replacement, of any device
or element of design
incorporated into any new
vehicle for the purpose of noise
control prior to its sale or
delivery to the ultimate
purchaser or while it is in
use; or
2. The use of the vehicle after such device or element of
design has been removed or
rendered inoperative by any
person.
Among those acts presumed to
constitute tampering are the acts
listed below. Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering the engine
speed governor, if equipped,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.
Removal of the fan clutch,
if equipped, or rendering the
clutch inoperative.
. Removal of the fan shroud,
if equipped.
Air Intake:
. Removal of the air cleaner
silencer.
. Modification of the air cleaner.
Exhaust:
. Removal of the muffler and/or
resonator.
. Removal of the exhaust pipes
and exhaust pipe clamps.

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 287
occurs, reverse the position of the
tires to equalize wear and get better
tire life.
In addition, when trucks are driven
continuously on high-crown roads,
an increase in air pressure of
35 kPa (5 psi) in the outer tire of a
dual tire operation will prolong outer
tire life. Be sure not to exceed the
inflation pressure limits shown on
the“VIN, Weight Rating, and
Greenhouse Gas (GHG) Emissions
Plate.” SeeVehicle Identification
Number (VIN) 0343.
Wheel and Tire Balancing
Proper tire balancing provides the
best riding comfort and helps to
reduce tire tread wear.
Out-of-balance tires can cause
annoying vehicle vibration and
uneven tire wear, such as cupping
and flat spots. See your authorized
dealer for wheel balancing.
Front End Alignment
Proper front end alignment improves
tire tread mileage. Your vehicle's
front end suspension parts should
be inspected often and aligned when needed. (See the
Maintenance Schedule for more
information.) Improper alignment will
not cause the vehicle to vibrate;
however, improper toe-in alignment
will cause front tires to roll at an
angle that will result in faster tire
wear. Incorrect caster or camber
alignment will cause your front tires
to wear unevenly, and may cause
the vehicle to "pull" to the left or
right.
Tire Traction
A decrease in driving, cornering and
braking traction occurs when water,
snow, ice, gravel or other material is
on the road surface. Driving
practices and vehicle speed should
be adjusted to the road conditions.
When driving on wet or slushy
roads, it is possible for a wedge of
water to build up between the tire
and road surface. This is known as
hydroplaning, and may cause partial
or complete loss of traction, vehicle
control and stopping ability; this
condition is also more likely with
worn tires.
To reduce the chance of traction
loss, follow these tips:
.
Slow down during rainstorms or
when roads are slushy.
. Slow down if the road has
standing water or puddles.
. Replace tires when front tread
depth is 3.2 mm (4/32 in.) and
rear tread depth is 1.6 mm
(2/32 in.).
. Keep tires properly inflated.
Tire Replacement
Recommendations
{Warning
Do not mix different construction
types of tires on your vehicle such
as radial, bias and bias-belted
tires except in emergencies,
because vehicle handling could
be affected and may result in loss
of vehicle control, or personal
injury or death. (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
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
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