Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 269
2. Fill the radiator to the base ofthe filler neck (2).
.Add enough engine coolant
to provide the required
cooling, freezing and
corrosion protection.
. Install the radiator cap.
3. Run the engine until the engine coolant temperature rises to
normal level, and idle the
engine for 10 minutes.
4. Turn off the engine. Make sure that the engine is cool.
Remove the radiator cap and
add engine coolant to the
radiator until it reaches the
base of the filler neck.
5. Install the radiator cap.
Check, replenish or change the
engine coolant only after the engine
has sufficiently cooled down.
When the engine is still hot, take
care to prevent engine coolant from
contact with the exhaust manifold.
Any such contact could result in
exhaust manifold damage. If you use the proper quality engine
coolant, there is no need to add
extra inhibitors or additives which
claim to improve the system. They
may be harmful to the proper
operation of the system.
Do not overfill the engine coolant
reserve tank.
If the level of engine coolant
changes rapidly, have your vehicle
inspected at your dealer.
Thermostat
The engine coolant temperature is
controlled by thermostat(s). The
thermostats stop engine coolant
flow through the radiator until a
preset temperature is reached. The
thermostats are installed in the
engine coolant outlet on the engine
block. The same thermostats are
used in both winter and summer.
When a replacement is needed,
genuine GM parts are
recommended.
Radiator Pressure Cap
The radiator cap, a 103 kPa (15 psi)
pressure type for gasoline vehicles
and a 108 kPa (16 psi) for dieselvehicles, must be installed tightly,
otherwise engine coolant may be
lost and damage to the engine may
result from overheating. The radiator
pressure cap should be checked
periodically for proper operation. If a
replacement is required, a genuine
GM part is recommended.
Engine Overheating
When the Engine Overheats
The engine cooling system may
overheat if the engine coolant level
is too low, if there is a sudden loss
of engine coolant (such as radiator
hose failure), or if other problems
occur. It may also temporarily
overheat during severe operating
conditions such as:
.
Climbing a long hill on a hot day.
. Stopping after high-speed
driving.
. Idling for long periods in traffic.
If engine power drops and the
needle on the engine coolant
temperature gauge goes up above
the upper limit of the safety zone
and enters the "H" zone, the engine
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
272 Vehicle Care
4. If no steam or engine coolantcan be seen or heard from the
engine compartment:
.Tilt the cab or open the
engine access cover.
‐If the engine coolant is
boiling, wait until it stops
before proceeding.
‐ Look at the see-through
reserve tank. The
engine coolant level
should be between the
"MAX" and "MIN" lines
on the reserve tank.
‐ If necessary, pour
engine coolant (See
Engine Coolant 0263
for the proper coolant
and water mixture) into
the reserve tank only,
not directly into the
radiator. Also, do not
check engine coolant
level at the radiator.
. Make sure the fan belts are
not broken, or off the
pulleys, and that the fan
turns when the engine is started. Make sure the fan
blade and pulleys are not
broken.
. Diesel engine only, check
the radiator hoses and
connections, heater hoses
and connections, radiator,
water pump, EGR cooler,
and SCR system and hoses
for leakage.
. Gasoline engine only, if the
engine coolant level in the
reserve tank is low, look for
leaks at the radiator hoses
and connections, heater
hoses and connections,
radiator, and water pump.
If the engine coolant level in
the reserve tank is at the
correct level but there is still
an indication on the
instrument panel of an
overheat condition:
You must let the engine
cool first. You may then add
engine coolant directly to
the radiator. See "Adding
Engine Coolant" under
Engine Coolant 0263. 5. Inspect to see if there is any
dirt, etc. attached to the front
surface of the radiator. Also,
inspect to see if there is
anything blocking the core.
If there is anything attached,
clean and remove it.
6. After the inspection, regardless of the vehicle condition, please
contact the nearest dealer.
Once the engine coolant
temperature gauge no longer
signals an overheat condition, you
can resume driving at a reduced
speed. Return to normal driving
after about 10 minutes if the gauge
pointer does not again show an
overheat condition.
When tap water only has been used
for engine coolant in an emergency,
change the engine coolant as soon
as possible.
Engine damage may be caused if
an overheating engine is suddenly
refilled with water. Instead, refill
slowly.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 273
Power Steering Fluid
The power steering fluid level must
be checked and it must be changed
according to the Maintenance
Schedule. SeeMaintenance
Schedule 0345.
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
For the 3.0L diesel vehicles, the
fluid level is correct if it is between
the “MAX” and“MIN” lines on the
reserve tank. If the level is lower
that the “MIN”line, add fluid up to
the “MAX” line.
For the 5.2L diesel vehicles, the
fluid level is correct if it is between
the“MAX” and“MIN” lines on the
reserve 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
install the cap and cover.
For single cab gasoline vehicles, the
fluid level is correct if it is between
the "MAX" and "MIN" lines on the oil
dipstick. If the level is lower than the
"MIN" line, add fluid up to the
"MAX" line.
The reserve tank is located at the
front left side of the engine.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
274 Vehicle Care
For crew cab gasoline vehicles,
open inspection sub cover, by
pulling the lock lever (red) (1) on the
driver’s seat cushion (2) to unlock it,
raise the cushion and remove the
sub cover. See Engine Cover0250.
When you have finished checking
the fluid level, securely install
the cap.The fluid level is correct if it is
between the "MAX" and "MIN" lines
on the oil dipstick. If the level is
lower than the "MIN" line, add fluid
up to the "MAX" line.
{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. (Continued)
Warning (Continued)
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
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.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
276 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 a 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 Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
278 Vehicle Care
major brake problems. As such,
mixing of these two fluids can
ultimately lead to vehicle fire or
other serious accidents.
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
depress the brake pedal at least 10
times in order to lower the
accumulator pressure to
atmospheric pressure. This is of
particular importance whenremoving 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 ATF Dexron
®-VI 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.
Free play (measured at the tip of pedal)
4 - 7 mm (0.16 - 0.28 in) (3500/4500)
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 279
5 - 10 mm (0.20 - 0.39 in)
(3500HD/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 (3500HD/ 4500HD/4500XD)
45 mm (1.77 in) or more (3500/4500)
Clearance between the brake
pedal and the brake pedal bracket
with a pressure of 294 N (66 lbs) applied to the brake pedal
45 mm (1.77 in) or more (3500/4500)
35 mm (1.38 in) or more (3500HD/ 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
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 281
Never mix the specified brake fluid
with fluids of another brand.
Be careful not to spill brake fluid
onto painted surfaces or to let it
come in contact with skin. If fluid is
spilled onto a painted surface or
comes in contact with skin, wash
away the fluid with water and
immediately wipe the area clean.
Brake fluid readily absorbs moisture.
Therefore, it is necessary to close
the brake fluid container tightly for
storage.
If the brake fluid level decreases
rapidly, there may be a problem in
the brake system or brake pads or
shoe linings may have worn out.
Have your vehicle inspected by the
nearest dealer immediately.Battery
Working Near Battery
Diesel Vehicle Shown, GasolineVehicle Similar
The batteries are located on the
outboard side of the left frame rail,
behind the cab. The batteries are in
a carrier with the cover (2) retained
by spring clips (1).
{Danger
Follow the precautions listed in
the jump starting Danger (see
"When the Battery is Discharged")
when working on or near the
battery. Personal injury
(particularly to eyes) or property
damage may result from battery
explosion, battery fluid or
electrical (short circuit) burns. You
and others could be seriously
injured or killed.
If the negative cable is disconnected
from the negative terminal on the
battery within 3 minutes after turning
the engine control switch to the
"LOCK" position, the engine control
module may malfunction.
Checking the Battery
Your new vehicle is equipped with
DELKOR (Diesel vehicles) or
CHAMPION (Gasoline vehicles)
batteries. They need no periodic
electrolyte level maintenance. Its
top is permanently sealed (except
for two small vent holes) and has no