2018 CHEVROLET LOW CAB FORWARD light

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
242 Vehicle Care
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. 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 switch
to 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

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Vehicle Care 243
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.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)

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Vehicle Care 245
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.Free play (measured at the tip of
pedal)
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.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
248 Vehicle Care
Danger (Continued)
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 batteries. They need no
periodic electrolyte level
maintenance. Its top is permanently
sealed (except for two small vent
holes) and has no filler caps. You
will never have to add water.
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
Battery posts, terminals and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive
harm. Wash hands after handling.
You and others could be seriously
injured.
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 Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
254 Vehicle Care
2. Continue pushing in the wiperrubber insert until the wiper
blade's hook engages with the
hole in it, and then confirm that
the rubber insert is securely
held in place.
3. Attach the wiper blade to the wiper arm.Headlamp Aiming
For vertical aiming, turn the two
screws indicated by arrows in the
diagram.
1. Remove the rubber beneath the headlight.
2. Two screws should be turned in the same direction at the
same time to adjust aiming.
3. When the headlamp aiming is out of position, contact your
dealer.
Bulb Replacement
Bulbs
1. Check each bulb for blowout.
2. If a bulb has blown out, replaceit. Always place the engine
control switch in the “LOCK”
position and place all the other
switches in the “OFF”position
before replacing the blown
bulbs.
3. If you need assistance replacing any bulbs, contact
your dealer.
Turn Signals
The flasher unit activates both the
turn signal circuits and the hazard
circuit. Should a lamp burn out, the
flasher unit will continue to operate.
Check the turn signal lamps visually
before the vehicle is used.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Vehicle Care 255
Bulb Wattage
{Warning
Using bulbs with a wattage other
than that specified could cause
the bulb or the wiring to become
hot. This could result in the
warping of the lens and case, and
it could also lead to the outbreak
of fire.
Bulbs are hot immediately after
they go out. When replacing the
bulbs, avoid being burned by
making sure they are fully cooled.
Never drive the vehicle with the
bulbs not working. This could
result in an accident.
You and others could be seriously
injured.
When one bulb of a pair of lamps,
such as a headlamp blows out, the
other bulb is approaching the end of
its useful life. We recommend that
both be changed at the same time. For the lamps (lighting equipment)
such as headlamps, inside of the
lens can mist up momentarily when
driving in the rain or during the car
wash. Also, the temperature
difference between inside and
outside of the lamps can sometimes
cause the water condensation
inside the lens. This is not abnormal
because this is the same
phenomenon as the windshield or
door glass fogs up when it rains. If it
is demisted minutes after the lamp
is turned on, things are normal.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
256 Vehicle Care
Bulb Wattage
PositionLights Bulb Wattage (12V)Qty.
Front Headlight Highbeam/Lowbeam
60/55W2
Front Turn Signal Lamp 27W (Amber)2
Parking Lamp 5W2
Cornering Lamp 27W2
Side Turn Signal Lamp 5W (Amber)2
Sidemarker Lamp 5W (Amber)2
Rear Taillamp and Stoplamp
8/27W2
Turn Signal Lamp 27W2
Back-Up Lamp 27W2
License Plate Lamp 7.5W1
Roof Roofmarker Lamp
(Identification/Clearance Lamp) 5W
5
Interior Dome Light
10W1
Speedometer and Gauge Lights 3.4W5
Warning/Indicator Lights LED20

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Vehicle Care 257
Contact your dealer when replacing
lights that are not listed here.
Headlamps and Front
Turn Signal
Replacing the Headlamps
When the bulb has blown out,
replace it with a bulb of the
specified wattage. Be careful not to
excessively tighten the mounting
screws when replacing the
headlamp bulbs.
Do not replace a bulb with other
than the specified wattage.
Proper aiming of the headlamps is
important to ensure sufficient
illumination of the highway without
blinding other motorists. When
replacing headlamp bulbs, have the
headlamp aim adjusted at your
dealer.
When replacing a bulb, make sure
the light switch is“OFF”.
See Bulb Replacement 0254.
1. Remove the front grille (3).
Remove the screw (4) from the
center of the grille. Push up on
the tabs of the five clips (1) on
the upper side of the grille and
pull the grille toward you to
remove it. Loosen the nuts (2)
for the turn signal light.2. Remove the turn signal lamp.Open the front door. Use a
phillips head screwdriver to
remove the two screws
between the door and the cab.