Paccar PX-7 User manual

Operator’s Manual
Operators Manual’2019-2020 Model Years
2017 Emissions
Warranty

Engine Operation..................................... 1
Engine Maintenance..................................... 2
Engine Warranty..................................... 3
Contents

© 2019 PACCAR Inc. - All Rights Reserved
This manual illustrates and describes the operation of features or equipment which may be either
standard or optional on this vehicle. This manual may also include a description of features and
equipment which are no longer available or were not ordered on this vehicle. Please disregard any
illustrations or descriptions relating to features or equipment which are not on this vehicle. PACCAR
reserves the right to discontinue, change specifications, or change the design of its vehicles at any
time without notice and without incurring any obligation. The information contained in this manual is
proprietary to PACCAR. Reproduction, in whole or in part, by any means is strictly prohibited without
prior written authorization from PACCAR Inc.
Contents

Chapter 1 | ENGINE OPERATION
In this Chapter:
Safety - Introduction..............................................................................................................................5
Emergency - What To Do If.................................................................................................................10
Operating Instructions.........................................................................................................................13
ENGINE OPERATION -
4 Y53-1183-1G1 (05/19)
1

Safety - Introduction
Using this Manual
Please take the time to get acquainted with
your vehicle by reading this Operator’s
Manual. We recommend that you read and
understand this manual from beginning to
end before you operate this equipment.
This manual contains useful information for
the safe and efficient operation of this
equipment. It also provides service
information, with an outline for performing
safety checks and basic preventive
maintenance inspections. We have tried to
present the information you’ll need to learn
about functions, controls, and operation—
and to present it as clearly as possible. We
hope you’ll find this manual easy to use.
There will be times when you need to take
this manual out of the glovebox. When you
do, please be sure to return it when you
are finished using it. That way it will be
there when you need it the next time or
when you pass the vehicle on to the next
user.
NOTE
After you've read this manual, it should
be stored in the cab for convenient ref-
erence and remain with this truck
when sold.
Your vehicle may not have all the features
or options mentioned in this manual.
Therefore, you should pay careful attention
to the instructions that pertain to just your
vehicle. In addition, if your vehicle is
equipped with special equipment or options
not discussed in this manual, consult your
dealer or the manufacturer of the
equipment.
There are several tools built into this
manual to help you find what you need
quickly and easily. First is the Quick Table
of Contents. Located at the front of the
manual, this lists the main subjects
covered and gives section numbers where
you can find these subjects. Use the Quick
Table of Contents to find information on a
large subject like “Maintenance.” Cross-
referenced citations also help you get the
information you need. If some other part of
the manual contains further information on
the subject you are reading about, we’ll
indicate that in a cross-reference like this:
(See Safety Alerts on page 5). You won’t
have to go searching for more information.
Finally you’ll find a helpful Subject Index.
It’s in the back of the manual and
alphabetically lists the subjects covered.
So if you want information on brakes, for
example, just look under Brake in the
Subject Index. You’ll find all the pages
listed where brakes or braking are
discussed.
All information contained in this manual is
based on the latest production information
available at the time of publication.
Kenworth Truck Company Peterbilt Motors
Company reserves the right to make
changes at any time without notice.
Safety Alerts
Read and follow all of the safety alerts
contained in this manual. They are there
for your protection and information. These
alerts can help you avoid injury to yourself,
your passengers, and help prevent costly
damage to the vehicle. Safety alerts are
highlighted by safety alert symbols and
signal words such as “WARNING,”
“CAUTION,” or “NOTE.” DO NOT ignore
any of these alerts.
ENGINE OPERATION - Safety - Introduction
Y53-1183-1G1 (05/19) 5
1

Warnings
The safety message following this symbol
and signal word provides a warning against
operating procedures which could cause
death or injury. They could also cause
equipment or property damage. The alert
will identify the hazard, how to avoid it, and
the probable consequence of not avoiding
the hazard.
Example:
WARNING
Hot engine oil can be dangerous. You
could be burned. Let the engine oil
cool down before changing it. Failure
to comply may result in death, person-
al injury, equipment or property dam-
age.
Cautions
The safety message following this symbol
and signal word provides a caution against
operating procedures which could cause
equipment or property damage. The alert
will identify the hazard, how to avoid it, and
the probable consequence of not avoiding
the hazard.
Example:
CAUTION
Continuing to operate your vehicle with
insufficient oil pressure will cause seri-
ous engine damage. Failure to comply
may result in equipment or property
damage.
Notes
The message following this symbol and
signal word provides important information
that is not safety related but should be
followed. The alert will highlight things that
may not be obvious and is useful to your
efficient operation of the vehicle.
Example:
NOTE
Pumping the accelerator will not assist
in starting the engine.
Forward
This manual contains information for the
correct operation and maintenance of your
PACCAR engine. Read and follow all
safety instructions. Refer to the WARNING
in the General Safety Instructions on page
7. Keep this manual with the equipment.
If the equipment is traded or sold, give the
manual to the new owner.
The information, specifications, and
recommended maintenance guidelines in
this manual are based on information in
effect at the time of printing. PACCAR
reserves the right to make changes at any
time without obligation. If you find
differences between your engine and the
information in this manual, contact your
local PACCAR Authorized Repair Location
or write to:
PACCAR c/o PACCAR Engines
PO Box 1518 Bellevue, WA 98009
ENGINE OPERATION - Safety - Introduction
6 Y53-1183-1G1 (05/19)
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The latest technology and the highest
quality components were used to produce
this engine. When replacement parts are
needed, we recommend using only
genuine parts from PACCAR.
NOTE
Warranty information including the
EPA and California Emission Warranty
is located in the section entitled “En-
gine Warranty.” Make sure you are fa-
miliar with the warranty or warranties
applicable to your engine.
Illustrations
Some of the illustrations throughout this
manual are generic and will not look
exactly like the engine or parts used in
your application. The illustrations can
contain symbols to indicate an action
required and/or an acceptable or
unacceptable condition.
The illustrations are intended to show
repair or replacement procedures. The
procedure will be the same for all
applications, although the illustrations may
differ.
General Safety Instructions
WARNING
Improper practices, carelessness, or
ignoring any warnings may cause
property damage, personal injury, or
death.
Before performing any repair, read and
understand all of the safety precautions
and warnings. The following is a list of
general safety precautions that must be
followed to provide personal safety. Failure
to follow these instructions may cause
death or injury. Special safety precautions
are included in the procedures when they
apply.
Keep in mind that even a well maintained
vehicle must be operated within the range
of its mechanical capabilities and the limits
of its load ratings. See the Weight Ratings
label on the driver's door edge.
Every new vehicle is designed to conform
to all Federal Motor Vehicle Safety
Standards applicable at the time of
manufacture. Even with these safety
features, continued safe and reliable
operation depends greatly upon regular
vehicle maintenance. Follow the
maintenance recommendations found in
Preventive Maintenance section. This will
help preserve your investment.
Make sure your vehicle is in top working
condition before heading out on the road, it
is the responsible driver's duty to do so.
Inspect the vehicle according to the
Driver's Check List.
• Use the proper tool for manually
rotating the engine. DO NOT
attempt to rotate the crankshaft by
pulling or prying on the fan. This
practice can cause death, personal
injury, equipment damage, or
damage to the fan blades, causing
premature fan failure.
• Work areas should be dry, well lit,
well ventilated, free from clutter,
loose tools, parts, ignition sources
and hazardous substances.
• Wear protective glasses and
protective shoes when working.
• DO NOT wear loose-fitting or torn
clothing. Tie back and/or tuck in
long hair. Remove all jewelry when
working.
• Before beginning any repair,
disconnect the battery (negative [-]
cable) and discharge any
capacitors.
ENGINE OPERATION - Safety - Introduction
Y53-1183-1G1 (05/19) 7
1

• Put a “DO NOT OPERATE” tag in
the operator's compartment or on
the controls.
• Allow the engine to cool before
slowly loosening the coolant filler
cap to relieve the pressure from the
cooling system.
WARNING
Removing the fill cap on a hot engine
can cause scalding coolant to spray
out and burn you badly. If the engine
has been in operation within the previ-
ous 30 minutes, be very careful in re-
moving the fill cap. Protect face,
hands, and arms against escaping flu-
id and steam by covering the cap with
a large, thick rag. DO NOT try to re-
move it until the surge tank cools down
or if you see any steam or coolant es-
caping. Always remove the cap very
slowly and carefully. Be ready to back
off if any steam or coolant begins to
escape.
• Always use wheel chocks or proper
jack stands to support the vehicle
or vehicle components before
performing any service work. DO
NOT work on anything that is
supported only by lifting jacks or a
hoist. Before resting a vehicle on
jack stands, be sure the stands are
rated for the load you will be
placing on them.
• Before removing or disconnecting
any lines, fittings, or related items,
relieve all pressure in the air, oil,
fuel, and cooling systems. Remain
alert for possible pressure when
disconnecting any device from a
system that contains pressure.
High pressure oil or fuel can cause
death or personal injury.
• Always wear protective clothing
when working on any refrigerant
lines and make sure that the
workplace is well ventilated.
Inhalation of fumes can cause
death or personal injury. To protect
the environment, liquid refrigerant
systems must be properly emptied
and filled using equipment that
prevents the release of refrigerant
gas. Federal law requires capturing
and recycling refrigerant.
• When moving or lifting any heavy
equipment or parts, make sure to
use proper techniques and
assistance. Ensure all lifting
devices such as chains, hooks, or
slings are in good condition and
are of the correct load capacity.
Make sure all lifting devices are
positioned correctly.
• Corrosion inhibitors and lubricating
oils may contain alkali. DO NOT
get the substance in eyes and
avoid prolonged or repeated
contact with skin. DO NOT
swallow. If ingested, seek
immediate medical attention. DO
NOT induce vomiting. In case of
contact, immediately wash skin
with soap and water. In case of
harmful contact, immediately
contact a physician. Always keep
any chemicals OUT OF REACH
OF CHILDREN.
• Naphtha and Methyl Ethyl Ketone
(MEK) are flammable materials and
must be used with caution. Follow
the manufacturer's instructions to
ensure safety when using these
materials. Always keep any
chemicals OUT OF REACH OF
CHILDREN.
• When working on the vehicle, be
alert for hot parts on systems that
have just been turned off, exhaust
gas flow, and hot fluids in lines,
ENGINE OPERATION - Safety - Introduction
8 Y53-1183-1G1 (05/19)
1

tubes, and compartments. Contact
with any hot surface may cause
burns.
• Always use tools that are in good
condition. Make sure you have the
proper understanding of how to use
the tools before performing any
service work. Use only genuine
replacement parts from PACCAR.
• Always use the same fastener part
number (or equivalent) when
replacing items. DO NOT use a
fastener of lesser quality if
replacements are necessary. (e.g.,
DO NOT replace a SAE 10.9 grade
with 8.8 grade fastener.)
• Always torque fasteners and fuel
connections to the required
specifications. Overtightening or
under-tightening can allow leakage.
• Close the manual fuel valves prior
to performing maintenance and
repairs, and when storing the
vehicle inside.
• DO NOT perform any repair when
impaired, tired, fatigued, or after
consuming alcohol or drugs that
can impair your functioning.
• Some state and federal agencies in
the United States of America have
determined that used engine oil
can be carcinogenic and can cause
reproductive toxicity. Avoid
inhalation of vapors, ingestion, and
prolonged contact with used engine
oil.
• DO NOT connect the jump starting
or battery charging cables to any
ignition or governor control wiring.
This can cause electrical damage
to the ignition or governor.
• Coolant is toxic. If not reused,
dispose of coolant in accordance
with local environmental
regulations.
CAUTION
Corrosive chemicals can damage the
engine. DO NOT use corrosive chemi-
cals on the engine. Failure to comply
may result in equipment or property
damage.
California Proposition 65 Warning
• Diesel engine exhaust and some of
its constituents are known to the
State of California to cause cancer,
birth defects, and other
reproductive harm.
• The catalyst substrate located in
the Diesel Particulate Filter (DPF)
contains vanadium pentoxide,
which has been determined by the
State of California to cause cancer.
Always wear protective clothing
and eye protection when handling
the catalyst assembly. Dispose of
the catalyst in accordance with
local regulations. If catalyst
material gets into the eyes,
immediately flood eyes with water
for a minimum of 15 minutes. Avoid
prolonged contact with skin. In
case of contact, immediately wash
skin with soap and water. In case
of harmful contact, immediately
contact a physician.
• Other chemicals in this vehicle are
also known to the State of
California to cause cancer, birth
defects or other reproductive harm.
• 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.
ENGINE OPERATION - Safety - Introduction
Y53-1183-1G1 (05/19) 9
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Emergency - What To Do If
Roadside Assistance
Call toll-free to talk to someone at the
PACCAR Customer Center:
• Kenworth customers call: 1-800-
KW-Assist (1-800-592-7747) |
Peterbilt customers call:
1-800-4Peterbilt (800-473-8372)
• Open 24-7-365 days a year.
• They can help you get roadside
assistance.
• They have a custom mapping
system which locates authorized
PACCAR engine dealers and
Independent Service Providers
(ISPs) near you and lists types of
services offered, hours of operation
and contact information.
• They can assist with jump and pull
starts, tires, trailers, fines and
permits, chains, towing, hazardous
clean-up, out of fuel (roadside),
mechanical repairs and preventive
maintenance services.
• They have multilingual agents and
access to a translation service to
ensure quality assistance for
customers in any language.
• They can’t answer your warranty
questions, but can get you in
contact with an authorized dealer
who can.
• The PACCAR Customer Center
service is FREE.
Stop Engine Lamp
12
The stop engine warning lamp will
illuminate, and an audible tone will sound,
when a major engine problem exists. Your
vehicle will be equipped with one of the
indicators above, 1 or 2, depending on the
engine model.
WARNING
If the Stop Engine warning lamp illumi-
nates, it means you have a serious en-
gine system problem. This should be
considered an emergency. You should
stop the vehicle as safely as possible
and turn OFF the ignition. The vehicle
must be serviced and the problem cor-
rected before driving again. Failure to
comply may result in death, personal
injury, equipment or property damage.
For engines with the engine-protection
shutdown feature enabled, the stop engine
lamp will begin to flash 30 seconds before
the engine automatically shuts down. The
warning lamp alerts the operator to the
impending shutdown.
The lamp will also illuminate when the DEF
tank is almost empty or the soot level in the
DPF is at full capacity. At this level
warning, regeneration cannot be performed
and engine power will be derated.
Engine may automatically shut down if the
check engine lamp and stop engine lamp
are illuminated and the operator does not
correct the condition.
ENGINE OPERATION - Emergency - What To Do If
10 Y53-1183-1G1 (05/19)
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Engine Oil Pressure Lamp Turns
On
It is important to maintain oil pressure
within acceptable limits. If oil pressure
drops below the minimum psi a red
warning lamp on the oil pressure gauge
and the Stop Engine Lamp will come ON.
CAUTION
Continuing to operate your vehicle with
insufficient oil pressure will cause seri-
ous engine damage. Failure to comply
may result in equipment or property
damage.
• If the oil pressure fails to rise within
10 seconds after the engine starts,
stop the engine and determine the
cause.
• See Engine Oil Specification for the
correct oil pressure ranges for your
vehicle's engine.
• If the oil pressure suddenly drops,
or the audible alarm and engine oil
pressure warning light come on
while driving, do the following:
1. Slow down carefully.
2. Move a safe distance off the road
and stop.
3. Place the transmission in neutral
(N) and set the parking brake. (See
Parking Brake Valve and Operating
the Transmission in your vehicle
Operator's Manual, for
transmission shifting and parking
brake information.)
4. Turn OFF the engine.
5. Turn ON the emergency flasher
and use other warning devices to
alert other motorists.
6. Wait a 15-20 minutes to allow oil to
drain into the engine oil pan, and
then check the oil level. See
Engine Oil Level.
7. Add oil if necessary. If the problem
persists, contact an authorized
PACCAR engine dealer as soon as
possible.
Check Engine Lamp Turns On
Or
Check Engine Lamp - Turns on when a
problem exists, but the vehicle can still be
safely driven. Vehicle should be serviced to
correct the problem but the situation should
not be considered an emergency.
The lamp will also illuminate when a DPF
regeneration or addition of diesel exhaust
fluid (DEF) is required. For PACCAR PX
Engines, this icon may also illuminate if the
crankcase breather element needs
attention. Another function of the check
ENGINE OPERATION - Emergency - What To Do If
Y53-1183-1G1 (05/19) 11
1

engine lamp is to warn the operator of an
impending idle shutdown. When the idle
shutdown timer is 30 seconds from
expiring, the ECM begins flashing the
check engine warning lamp once per
second. When the timer expires, the ECM
will turn off the warning lamp and shut
down the engine.
Engine is Overheating
CAUTION
The cooling system may overheat if
the engine coolant is at the minimum
level. A sudden loss of coolant,
caused by a split hose or broken hose
clamp could also lead to an overheat
condition. Always inspect to ensure
hoses and clamps are not cracked,
worn, or loose. Failure to comply may
result in equipment or property dam-
age.
NOTE
The system may also temporarily over-
heat during severe operating condi-
tions such as:
• Climbing a hill on a hot day
• Stopping after high-speed/high-
load driving
• Debris blocking air flow through
the cooling module (radiator)
If the engine coolant temperature warning
lamp comes on and the audible alarm
sounds showing an overheat condition, or
if you have any other reason to suspect the
engine may be overheating, DO NOT
TURN OFF THE ENGINE unless a low
water warning device indicates a loss of
coolant.
Follow these steps if the engine coolant
temperature is rising, or the temperature is
already above normal, and there are no
other warning alarms displayed in the
instrument cluster.
NOTE
The instrument cluster gauges may
appear, if hidden from view, change
brightness and change color to bring
attention to a particular system.
1. Reduce engine speed, or stop.
When stopped, place the
transmission in neutral (N) and set
the parking brake. Keep the engine
running. See the vehicle operator's
manual for instructions on
transmission shifting and parking
brake information.
ENGINE OPERATION - Emergency - What To Do If
12 Y53-1183-1G1 (05/19)
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WARNING
To reduce the chance of personal in-
jury, vehicle damage, and/or death
from overheated engines, which can
result in a fire, never leave the engine
idling without an alert driver present. If
the engine does overheat, as indicated
by the engine coolant temperature
lamp, immediate action is required to
correct the condition. Continued unat-
tended operation of the engine, even
for a short time, may result in serious
engine damage or a fire. Failure to
comply may result in death, personal
injury, equipment or property damage.
WARNING
Removing the fill cap on a hot engine
can cause scalding coolant to spray
out and burn you badly. If the engine
has been in operation within the previ-
ous 30 minutes, be very careful in re-
moving the fill cap. Protect face,
hands, and arms against escaping flu-
id and steam by covering the cap with
a large, thick rag. DO NOT try to re-
move it until the surge tank cools down
or if you see any steam or coolant es-
caping. Always remove the cap very
slowly and carefully. Be ready to back
off if any steam or coolant begins to
escape.
NOTE
Keep the engine running at idle speed
unless a warning icon turns on that re-
quires the engine to be shut off.
2. Check to ensure the Oil Pressure
Gauge reads normal.
3. Make sure the engine fan is turning
by switching the Engine Fan Switch
from AUTO to MAN (Manual).
4. Idle the engine to see if this
reduces the coolant temperature. If
the temperature does not begin to
drop, shut off the engine and
contact your nearest authorized
dealer.
5. If the temperature begins to return
to normal, allow the engine to idle 3
to 5 minutes before shutting it off.
This allows the engine to cool
gradually and uniformly.
6. If overheating came from severe
operating conditions, the
temperature should have cooled by
this time. If it has not, stop the
engine and let it cool before
checking to see if the coolant is
low.
7. Be sure the vehicle is parked on
level ground or the readings may
be incorrect. Check the coolant
level at the coolant surge tank.
Check the coolant level after each trip
when the engine has cooled. The coolant
level should be visible within the surge
tank. Add coolant if necessary.
Operating Instructions
Engine Warning Lamps
The following engine warning lamps
section covers only the lamps controlled by
the engine’s Electronic Control Module
(ECM). Please refer to the vehicle
“Operator's Manual” and “Engine
Aftertreatment Systems” manuals for
additional warning lamp information.
ENGINE OPERATION - Operating Instructions
Y53-1183-1G1 (05/19) 13
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CAUTION
The installation of electronic devices to
the On Board Diagnostics (OBD) con-
nector, the vehicle Controller Area Net-
work (CAN), or their associated wiring
is not permitted. Doing so can ad-
versely affect vehicle performance
and/or cause fault codes to be record-
ed. The OBD connector is provided for
temporary connection of service tools
and for diagnostic purposes only.
Stop Engine Lamp
12
The stop engine warning lamp will
illuminate, and an audible tone will sound,
when a major engine problem exists. Your
vehicle will be equipped with one of the
indicators above, 1 or 2, depending on the
engine model.
WARNING
If the Stop Engine warning lamp illumi-
nates, it means you have a serious en-
gine system problem. This should be
considered an emergency. You should
stop the vehicle as safely as possible
and turn OFF the ignition. The vehicle
must be serviced and the problem cor-
rected before driving again. Failure to
comply may result in death, personal
injury, equipment or property damage.
For engines with the engine-protection
shutdown feature enabled, the stop engine
lamp will begin to flash 30 seconds before
the engine automatically shuts down. The
warning lamp alerts the operator to the
impending shutdown.
The lamp will also illuminate when the DEF
tank is almost empty or the soot level in the
DPF is at full capacity. At this level
warning, regeneration cannot be performed
and engine power will be derated.
Engine may automatically shut down if the
check engine lamp and stop engine lamp
are illuminated and the operator does not
correct the condition.
Engine, Check Engine
Or
Illuminates when a non emissions related
problem exists, but the vehicle can still be
safely driven. Vehicle should be serviced to
correct the problem but the situation should
not be considered an emergency.
Malfunction Indicator Lamp
Illuminates when an engine emissions
failure has occurred. The vehicle can be
safely driven but should be serviced to
correct the problem. The situation should
not be considered an emergency. In some
cases, the Malfunction Indicator Lamp
(MIL) will activate in conjunction with the
High Exhaust System Temperature
ENGINE OPERATION - Operating Instructions
14 Y53-1183-1G1 (05/19)
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(HEST), Diesel Particulate Filter (DPF) and
Diesel Exhaust Fluid (DEF) warning lamps.
NOTE
The malfunction indicator lamp (MIL)
will illuminate if the on-board diagnos-
tics (OBD) system detects a possible
emissions system failure. The vehicle
should be brought in for service at the
next opportunity to ensure the condi-
tion is corrected.
Diesel Particulate Filter (DPF)
Warning Lamp
This warning symbol will appear when the
DPF needs to be regenerated and then
also during the regeneration cycle. This
icon may also appear if the system is
attempting to automatically regenerate
while the vehicle is in Power Take Off
operation mode.
Engine aftertreatment system includes a
diesel particulate filter and DPF warning
lamp.
High Exhaust System Temperature
(HEST) Warning Lamp
Keep vehicle a safe distance from
combustible items.
WARNING
Temperature of the tail pipe, exhaust
pipe, the diesel particular filter (DPF)/
selective catalytic reduction (SCR) de-
vice and surrounding components in-
cluding enclosures and steps, will be
elevated during and shortly after a re-
generation event or normal vehicle op-
eration when engine is under high or
heavy loading.
If the High Exhaust System Temperature
(HEST) warning lamp is on:
• Do not park in an area of
combustible vapors or materials.
You must keep combustibles at
least 5 ft. (1.5 m) away from the
exhaust (outlet) stream (as it exits
the tail pipe) while the HEST lamp
is illuminated. Always park your
vehicle outside. Failure to do so
could ignite an explosion or harm
bystanders which could result in
serious injury.
• Do not park in an area where
people are close by. You must keep
combustibles at least 5 ft. (1.5 m)
away from the exhaust outlet while
the HEST lamp is illuminated.
Failure to do so could result in
serious injury.
• Do not approach the exhaust
system or surrounding areas
without allowing adequate time for
the system to cool down. Failure to
do so could result in serious burns
to the skin.
Diesel Exhaust Fluid (DEF) Lamp
The engine aftertreatment system includes
a diesel exhaust fluid (DEF) warning lamp
ENGINE OPERATION - Operating Instructions
Y53-1183-1G1 (05/19) 15
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on the DEF gauge and additional warning
lamps in the instrument cluster.
DEF Warning Lamp in Instrument Cluster
Diesel Exhaust Fluid (DEF) Gauge
2
1
1. DEF Symbol
2. DEF gauge warning lamp
The DEF lamp(s) will illuminate when the
fluid in the DEF tank reaches a low level. If
the lamp illuminates but the level is full,
seek service immediately for DEF fluid
quality or DEF equipment repair.
Engine Wait-To-Start Lamp
This warning icon will appear when the
system needs some time before attempting
to start the engine. The lamp will illuminate
at key ON, and will stay on for a period of
up to 30 seconds.
NOTE
The length of time the 'Wait-To-Start'
lamp remains illuminated depends on
the ambient temperature. The lower
the ambient temperature, the longer
the lamp will be illuminated.
Once the Wait-to-Start lamp turns off, turn
the key to the starting position to start the
engine.
You may see this appear if the system has
detected a situation where the starter is too
hot and needs to cool down. Alternatively,
you may see it when the engine grid heater
is on and needs some time to warm up.
(PACCAR PX and Cummins ISL engines)
NOTE
Some engines are equipped with an
engine starting motor protection fea-
ture. If the starting motor is engaged
for 30 or more seconds, without the
engine starting, the starter will be
locked out from operating, allowing for
proper cooling of the starting motor.
During this time, the 'Wait-To-Start'
lamp will flash for 2 minutes. Once the
lamp stops flashing, the starting motor
will be allowed to function.
Engine Braking System
An engine compression brake is standard
on the PX-7 engines. Optionally, this
engine may be equipped with an exhaust
brake. When activated, these devices
create a braking effect on the drive wheels.
Because it can help keep your vehicle’s
brakes from overheating, it can save wear
and tear on the service brakes. However,
the engine compression or exhaust brake
is not an emergency brake or the primary
vehicle brake.
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WARNING
DO NOT operate the engine compres-
sion brake when driving/operating your
vehicle bobtail or with a loaded or un-
loaded trailer on road surfaces with
poor traction (wet, icy, or snow cov-
ered roads) or in heavy traffic. There
may not be enough weight on the rear
axle to provide traction. Braking
caused by the normal operation of the
engine compression brake could
cause you to lose control of the vehi-
cle, resulting in an injury accident.
Make sure the engine brake is switch-
ed "OFF" when bobtailing or with an
unloaded trailer. Failure to comply may
result in death, personal injury, equip-
ment or property damage.
WARNING
The service brakes must be used in an
emergency. The engine compression
brake alone might not stop the vehicle
fast enough to prevent an accident.
The engine compression brake is NOT
intended as the primary brake for the
vehicle, nor is it an emergency brake.
The engine compression brake only
helps the service brakes by using en-
gine back pressure to slow the drive-
train. Use the service brakes for quick
stops. You could be seriously injured if
you relied only on the engine compres-
sion brake to stop the vehicle in an
emergency. Failure to comply may re-
sult in death, personal injury, equip-
ment or property damage.
CAUTION
DO NOT operate the engine brake un-
til the engine oil temperature is above
86°F (30°C). Operation below 86°F
(30°C) could cause severe damage to
the engine. Idle the engine four mi-
nutes at approximately 1,000 rpm to
warm the engine before activating the
engine brakes.
NOTE
If your vehicle is equipped with anti-
lock brakes (ABS), operation of the
compression brake (if turned ON) may
be interrupted if the ABS system de-
tects wheel-slip due to operation on
slippery surfaces.
Ideally (on normal road surfaces), you
should slow your vehicle with the
compression brake (where permitted by
law) and use the service brakes only for
stopping completely. Operating this way
will greatly prolong the life of the service
brakes.
Compression Brake
With the compression brake switch ON, the
brake automatically creates its braking
effect when you remove your foot from the
accelerator pedal.
The brake switch is located on the
accessory dash panel. It controls whether
the brake is ON (ready to slow the vehicle
down) or OFF (no braking action).
1. Do not use the engine compression
brake to slow the vehicle down
when you are bobtailing or pulling
an empty trailer.
2. Make sure the brake is OFF before
starting the engine.
3. After the engine is started, warmed
up and you are ready to get under
ENGINE OPERATION - Operating Instructions
Y53-1183-1G1 (05/19) 17
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way, turn the engine compression
brake switch ON for added braking
effect.
NOTE
If your vehicle is equipped with the Ea-
ton Vorad® system, operation of the
compression brake may be automati-
cally activated.
Compression Brake Controls
There are two switches on the dash panel
that control the engine compression brake.
A master switch turns the system ON or
OFF. A second switch, located next to the
master switch, controls the braking effect.
This switch allows you to choose
progressively stronger braking to slow the
vehicle down.
Engine compression brake controls
include:
• ON/OFF switch
• Three-position selector switch
• Clutch switch
• Throttle sensor
• Service brake pressure switch
• Eaton Vorad® Anti-Lock Braking
System
Engaging conditions for the engine
compression brake:
• Engine speed must be above 1,000
rpm.
• Coolant temperature must be
above 59°F (15°C).
Deactivation conditions for the engine
compression brake:
• Accelerator pedal is depressed.
• Clutch pedal is depressed.
• Engine speed falls below 800 rpm.
• ABS control is active.
• ECM recognizes a system
problem.
CAUTION
Operating the engine with a compres-
sion brake that will not automatically
deactivate (i.e. when the dash switch
is OFF, clutch pedal is depressed or
throttle is applied) will cause severe in-
ternal engine damage. DO NOT oper-
ate the engine if the compression
brake will not deactivate. Failure to
comply may result in equipment or
property damage.
Engine Compression Brake Level
Switch Operation
There are two switches that control your
vehicle’s engine compression brake. One
switch turns the system ON/OFF and the
second switch controls the braking level.
These switches are located on the dash
switch panel.
For the three-position engine compression
brake level switch, there will be 100
percent engine braking when the switch is
in the up (HIGH) position. In the middle
(MEDIUM) position, there will be 66
percent engine braking. In the down (LOW)
position there will be 33 percent engine
braking.
With the compression brake switch ON, the
compression brake will be engaged when
the service brake is applied. If the cruise
control is operated in conjunction with the
compression brake, the compression brake
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