2018 CHEVROLET LOW CAB FORWARD fuel pump

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 175
If the DEF level becomes too low or
incorrect fluid is added to the DEF
tank, the warning buzzer will sound,
warning and indicator lights will
come on and engine power will be
reduced. If you see these warning
and indicator lights, add DEF as
soon as possible or have your
vehicle serviced as soon as
possible.
Continuing to drive for too long after
these lights come on will result in
additional warnings, more engine
power reduction and will eventually
result in a severe vehicle speed
limitation. See“Diesel Exhaust
Fluid (DEF) Low Level Warning” and
“Incorrect Diesel Exhaust Fluid
(DEF)/SCR System Malfunction
Warnings” later in this section.
{Warning
Do not touch the water that
comes out from the muffler. The
water is mildly acidified due to the
action of oxidation catalyst inside
the muffler. In the event that the
(Continued)
Warning (Continued)
fluid does come into contact with
your skin, completely wash it off
with water. You and others could
be seriously injured.
Do not relocate or modify the
exhaust pipe, muffler, DPF, SCR,
or DEF tank, which may affect the
exhaust gas cleaning performance.
If any relocation or modification is
necessary, consult your dealer.
The SCR system continues to
operate for approximately 3 minutes
after the engine control switch is
turned to the "LOCK" position. It is
normal to hear a buzzing type noise
from the DEF supply pump
(mounted on the left side frame rail
behind the cab) during the
shutdown process.
If it is necessary to disconnect the
batteries for any reason, be sure to
wait at least 3 minutes after turning
the engine control switch to the
"LOCK" position. This will allow the SCR system to properly complete
its shutdown processes. See
Winter
Driving 0133.
Diesel Exhaust Fluid (DEF) Low
Level Warning
Diesel Exhaust Fluid (DEF) is a
required fluid for the operation of
your diesel engine just as diesel fuel
is required. To avoid running out of
DEF your vehicle will turn on
warning and indicator lights and
reduce engine power in progressive
stages to encourage adding DEF.
The following is a summary of the
diesel exhaust fluid (DEF) low level
warning lights, indicator lights and
engine power reductions.
Continuing to drive for too long after
these lights come on will eventually
result in a severe vehicle speed
limitation.
These warning and indicator lights
will go out automatically and engine
power will be restored to normal
after the SCR system detects that
the DEF tank is refilled with DEF.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
206 Driving and Operating
Exhaust Brake Function
Diesel Vehicles Equipped with
Exhaust Brake-interlocked Cruise
Automatic activation of the exhaust
brake during cruise control driving
suppresses an increase in the
speed on a downhill slope,
decreasing the need for the driver to
apply the regular brake pedal. The
exhaust brake does not activate
when the exhaust brake switch is
turn off.
The maximum slope angle at which
the system can control the vehicle
speed increase is different
depending on the load the vehicle is
carrying.
Automatic Activation and
Automatic Release of Exhaust
Brake
The exhaust brake is engaged when
the vehicle speed exceeds the set
speed on a downhill slope.
The exhaust brake is disengaged
when the vehicle slows down close
to the set.
Fuel
Fuel for Diesel Engines
Diesel Fuel Requirement and
Fuel System
Fuel Requirements
Use of fuels other than ultra
low-sulfur fuel may not conform to
emission regulations.
The fuel supply pump, injector or
other parts of the fuel system and
engine can be damaged if you use
any fuel or fuel additive other than
those specifically recommended by
the dealer.
To help avoid fuel system or engine
damage, pay attention to the
following:
.Some service stations mix used
engine oil with diesel fuel. Some
manufacturers of large diesel
engines allow this; however, for
your diesel engine, do not use
diesel fuel which has been
contaminated with engine oil.
Besides causing engine
damage, such fuel can also affect emission control. Before
using any diesel fuel, check with
the service station operator to
see if the fuel has been mixed
with engine oil.
. Do not use any fuel additive
(other than as recommended
under "Biocides" in Water in
Fuel 0209). At the time this
manual was printed, no other
fuel additive was recommended.
(See your authorized dealer to
find out if this has changed.)
. Take care not to run out of diesel
fuel. If you do run out of fuel,
you may need to bleed air out of
the supply pump to re-start the
engine after fuel has been filled.
Your vehicle is designed to use
either Number 1-D or Number 2-D
diesel fuel. However, for better fuel
economy, use Number 2-D diesel
fuel whenever possible. At
temperatures below -7 °C (20 °F),
Number 2-D fuel may pose
operating problems (see "Cold
Weather Operation" which follows).
At colder temperatures, use Number
1-D fuel (if available) or use a

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
208 Driving and Operating
At temperatures below 0 °C (32 °F),
it is recommended to switch to Ultra
Low Sulfur Diesel fuel with no
biodiesel content, or to blends with
biodiesel containing less than 5% by
volume. At these extreme cold
temperatures, biodiesel blends
higher than 5% by volume may
cause fuel filter plugging and
system gelling, which can lead to
vehicle operability problems.
Fuels improperly blended for cold
temperature operation may result in
restricted fuel filters and degraded
vehicle performance. The vehicle is
equipped with a fuel heating system
to provide a level of protection
against filter plugging from gelling or
waxing of conventional diesel fuel
and biodiesel blends. If the
operating temperature is far below
the temperature at which gelling or
waxing of the fuel occurs, the
system will not prevent all cases of
filter plugging.
If the vehicle experiences a fuel
filter restriction, the on-board
monitoring system will alert the
driver that the fuel filter requiresservice. The fuel filter, however, will
not prevent all damage caused by
poor quality biodiesel.
Biodiesel Blends
Use biodiesel blends that meet the
ASTM specification D6751.
Retail pumps dispensing blends
containing up to 5% biodiesel (B5)
are not required to be labeled with
the concentration of biodiesel.
Blends up to B5 must meet ASTM
D975 (Grades No. 2-D or No. 1-D
S15 Ultra Low Sulfur Diesel). When
refueling with a biodiesel blend
above B5, one of the following
labels should appear on the
dispenser:
Caution
Do not use blends containing
more than 20% biodiesel. Any
engine, fuel system, or exhaust
after-treatment system damage
would not be covered by the
vehicle warranty.
Blends containing more than 5%
and up to 20% biodiesel must meet
ASTM specification D7467
(Biodiesel blend, B6 - B20) and are
labeled with an orange or blue label.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 209
To reduce the risk of poor quality
fuel, purchase biodiesel blends from
a fuel supplier or fueling station
which sells BQ-9000 certified
biodiesel. See www.bq-9000.org for
a list of certified marketers.
Biodiesel Blends in Canada
Biodiesel blends that meet the CAN/
CGSB-3.522 specifications up to
20% (B20) can be used. Do not use
biodiesel blends above 20%, as
they may damage the engine and
fuel system.
Cold Weather Operation
Diesel fuel is sensitive to
temperature. All diesel fuel has a
certain amount of paraffin
components, which are high in
energy value and help improve fuel
economy. But, when temperatures
are below -7 °C (20 °F), the paraffin
components begin turning into wax
flakes. If temperatures are low
enough, these flakes can obstruct
the fuel filters and stop fuel from
reaching the engine.At low temperatures, wax flakes are
more likely to form in Number 2-D
fuel than in Number 1-D (or
"winterized" Number 2-D) fuel. For
best operation at temperatures
below -7 °C (20 °F), use Number
1-D, or Number 2-D which has been
blended with Number 1-D for winter
use. When temperatures are
consistently below (or near) -18 °C
(0 °F), use Number 1-D if at all
possible. Bear in mind, however,
that even Number 1-D fuel will form
wax flakes when temperatures are
extremely low.
Do not use home heating oil or
gasoline in your diesel engine;
either may cause engine damage.
The addition of kerosene will not
unplug a filter plugged with wax.
Warming a "waxed" filter to a
temperature of 0 °C to 10 °C (32 °F
to 50 °F) will return the wax to
solution. Filter replacement is not
normally required.
Water in Fuel
During refueling, it is possible for
water (and other contaminants) to
be pumped into your fuel tank along
with the diesel fuel. This can occur if
a service station does not regularly
inspect and clean its fuel tanks, or if
a service station receives
contaminated fuel from its
supplier(s).
To protect your engine from
contaminated fuel, there is a water
separator system on the engine
which allows you to drain excess
water from the fuel.
{Warning
The drained water/diesel fuel
mixture is flammable, and could
be hot. To help avoid personal
injury or death and/or property
damage, do not touch the fuel
coming from the water separator
drain valve, and do not expose
the fuel to open flames or sparks.
(Continued)

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 211
Fuel will be mixed in the drained
water. Dispose of it in a method
conforming to the regulatory
requirements in your state.
If the water separator (fuel filter)
requires frequent draining, have the
fuel system inspected at your
dealer.
Pre Fuel Filter (Chassis-side)1. Attach a plastic hose to the drain plug (2) on the bottom of
the chassis-side fuel filter and
put the other end of the hose in
a container placed beneath the
filter. 2. Loosen the drain plug and
move the priming pump (1) up
and down by hand between
10 and 20 times.
3. Fully tighten the drain plug (2) and move the priming pump (1)
several times.
Fuel Filter (Engine-side)1. Attach a plastic hose to the drain plug (2) on the bottom of
the engine-side fuel filter (1)
and put the other end of the
hose in a container placed
beneath the filter.
2. Loosen the drain plug andmove the priming pump up and
down by hand between 10 and
20 times.
3. Fully tighten the drain plug and move the priming pump several
times.
4. Test run the engine and check that there are no fuel leaks
from the drain plug of the
engine-side fuel filter. Also
check that the water separator
(fuel filter) warning light
stays off.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
212 Driving and Operating
Running Out of Fuel
When the Fuel Tank is Empty
When the fuel tank is empty, air will
enter the fuel system, so refueling
alone will not be enough to restart
the engine. Use the following
methods to bleed the fuel system.
Bleeding the Fuel System
Steps for Refueling1. Follow the directions in "Parking Brake Lever" under
Parking Brake 0200. 2. Select the correct fuel (See
"Diesel Fuel Requirement and
Fuel System"). Follow any
posted safety rules. Stand to
the side, never above or
opposite the filler opening.
3. Check that the fuel cap is tight, and see to it that engine oil,
engine coolant in the reservoir,
and washer fluid, etc. are at
proper levels. Then do the
Driver Daily Checklist.
See Owner Checks and Services
0 317.
Driving your vehicle until the fuel
tank is empty may activate the
check engine malfunction indicator
light. You do not need to have your
vehicle checked. After refueling,
perform the following:
. Bleed the fuel system.
. Start, turn off and restart the
engine three or four times.
. The check engine malfunction
indicator light will be cancelled. Before Starting the Engine
1. The priming pump (1) is
located on the outboard side of
the left frame rail, in front of the
batteries. Place a container
beneath the air bleed plug (2)
to receive fuel, and then fully
loosen the plug.
2. Attach a clear hose onto the air bleed plug, direct the clear
hose into a catch pan.
3. Pump the priming pump (1) up/ down for 65 times to get most
of the air bubbles out. Note fuel
was drawn into the filter bowl at
around 40 - 50 times.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 213
4. Fully retighten the air bleedplug (2) and wipe off any fuel
that may have adhered to the
plug or surrounding area.
5. Continue to operate the pump for 50 times.
6. Start the engine.
7. If the engine does not start, repeat steps 5 and 6 as
necessary until it does start.
After Starting the Engine 1. Without pressing the accelerator pedal, start the
engine.
2. After the engine has started, allow it to idle for about
5 seconds.
3. Fully press the accelerator pedal and increase the engine
speed to the maximum speed
for 10 seconds. (Repeat this
operation several times.)
Insufficient air bleeding can result in
faulty engine operation. Be sure,
therefore, to always carry out the
previous steps under "After starting
the engine".Filling the Tank
Be sure to obey the following
instructions when refueling the
vehicle:
. Stop the engine and close the
vehicle's doors and windows.
. Keep cigarettes and other
flames away from the vehicle.
. Before opening the fuel tank
filler cap, touch a metallic object
to discharge static electricity
from your body.
. When filling, place the nozzle
deeply into the fuel tank. If you
try to fill more fuel by pulling out
the nozzle from the fuel tank, the
fuel may spill out, thus causing
danger.
. Be sure to wipe off the fuel that
is spilled at refueling.{Warning
Fuel vapor is highly flammable.
Be careful not to inhale fuel vapor
when refueling the vehicle.
If you have a static charge
buildup on your body while
refueling the vehicle, a spark
caused by its discharge could
ignite the fuel, resulting in burns.
All parts of the refueling
procedure (from opening the fuel
tank filler cap to completing the
refueling and closing the fuel tank
filler cap) must be performed by
the same person.
Other people may be carrying
static electricity. Do not allow
them to approach the fuel filler.
The person performing the
refueling procedure must not
return to the seat in the cab
part-way through the procedure.
(Continued)

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Vehicle Care 297
form when rinsing with water. Clean
the blade by wiping with a cloth
soaked in a solution of one-half
water and one-half methanol
alcohol. Then rinse the blade with
water.
The windshield wiper arms may be
swung out, away from the glass, to
provide easy access for cleaning.
Do not hang on to the roofmarker
lights while cleaning the windshield
or damage may occur (resulting in
possible water leakage).
External Diesel Engine
Cleaning
The engine does not need periodic
cleaning, nor is it recommended.
If you insist on cleaning the engine,
clean it only when it is cold, never
when it is warm or hot, and never
when the engine is running.
Spraying or pouring water or other
fluids on your engine when it is
warm or hot, or when it is running,
can cause serious damage to the
engine and its components,
particularly the fuel supply pump.
Handling the Radiator and
Charge Air Cooler
Cleaning the Radiator Core and
Charge Air Cooler Core
Cooling efficiency is compromised
when there is dirt or dust plugging
air passages in the radiator core
and charge air cooler core. This can
also cause corrosion of these cores.
Wash the radiator core with tap
water every 24 months.
Make sure to turn the engine off and
remove the key from the engine
control switch before cleaning
cores.The engine, exhaust pipe, and
radiator will be hot immediately after
the vehicle is driven. Be careful
around these parts to prevent burns.
Clean the engine when it is cold.
Do not clean the radiator, charge air
cooler and their surrounding areas
using water that is supplied under
high pressure. Doing so may cause
damage.
When cleaning the radiator core (1)
and charge air cooler core (2) , do
not crush or damage the fins (3).
The fins are very fragile so be
careful not to bend them out of
shape. If they become deformed,