2021 RAM CHASSIS CAB brake fluid

SERVICING AND MAINTENANCE379
Use of biodiesel mixture in excess of 20% can
negatively impact the fuel filter's ability to
separate water from the fuel, resulting in
high pressure fuel system corrosion or
damage.
Ethanol blends are not recommended or
approved for use with your Cummins diesel
engine.
In addition, commercially available fuel addi -
tives are not necessary for the proper opera -
tion of your Cummins diesel engine.
INTERVENTION REGENERATION
S
TRATEGY — MESSAGE PROCESS FLOW
The Cummins diesel engine meets all
Environmental Protection Agency (EPA) Heavy
Duty Diesel Engine Emissions Standards,
resulting in one of the lowest emitting diesel
engines ever produced.

To achieve these emissions standards, your
vehicle is equipped with a state-of-the-art engine
and exhaust system. The engine and exhaust
after-treatment system work together to achieve
the EPA Heavy Duty Diesel Engine Emissions
Standards. These systems are seamlessly
integrated into your vehicle and managed by the Cummins Powertrain Control Module (PCM).
The PCM manages engine combustion to allow
the exhaust system’s catalyst to trap and burn
Particulate Matter (PM) pollutants, with no input
or interaction on your part.
If the engine is allowed to idle or the truck is
driven on low engine speed drive cycles for more
than two hours, the system will automatically
enter an emissions operating mode that will
increase the engine idle speed to 900 RPM
(1,050 RPM for Chassis Cab). While in this mode,
which is designed to help maintain the Diesel
Particulate Filter, the engine idle speed will return
to normal when the brake pedal is applied.
A small change in engine tone or a slight change
in engine performance while accelerating may
also be noticeable at speeds below 20 mph
(32 km/h). This operating mode may last for up
to an hour of idle time, or around 20 minutes of
driving time.

Additionally, your vehicle has the ability to alert
you to additional maintenance required on your
truck or engine Ú
page 90.
DIESEL EXHAUST FLUID
Diesel Exhaust Fluid (DEF) sometimes known
simply by the name of its active component,
UREA—is a key component of Selective Catalytic
Reduction (SCR) systems, which help diesel
vehicles meet stringent emission regulations.
DEF is a liquid reducing agent that reacts with
engine exhaust in the presence of a catalyst to
convert smog-forming nitrogen oxides (NOx)
into harmless nitrogen and water vapor
Úpage 440.
You can receive assistance in locating DEF in
the United States by calling 866-RAM-INFO
(866-726-4636). In Canada call
1–800–465–2001 (English) or
1–800–387–9983 (French)
WARNING!
A hot exhaust system can start a fire if you
park over materials that can burn. Such
materials might be grass or leaves coming
into contact with your exhaust system. Do not
park or operate your vehicle in areas where
your exhaust system can contact anything
that can burn.
8

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SERVICING AND MAINTENANCE387
(Continued)
BRAKE SYSTEM
In order to ensure brake system performance,
all brake system components should be
inspected periodically Ú page 354.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should be
checked when performing under the hood
service or immediately if the brake system
warning lamp indicates system failure.

If necessary, add fluid to bring level within the
designated marks on the side of the reservoir of the
brake master cylinder. Be sure to clean the top of
the master cylinder area before removing cap.
With disc brakes the fluid level can be expected
to fall as the brake linings wear. However, an
unexpected drop in fluid level may be caused by
a leak and a system check should be conducted.

For further information Ú
page 444.
AUTOMATIC TRANSMISSION
Special Additives

The manufacturer strongly recommends against
using any special additives in the transmission.
Automatic Transmission Fluid (ATF) is an
engineered product and its performance may be
impaired by supplemental additives. Therefore,
do not add any fluid additives to the transmission.
The only exception to this policy is the use of special
dyes for diagnosing fluid leaks in six-speed
transmissions. Avoid using transmission sealers as
they may adversely affect seals.

WARNING!
Riding the brakes can lead to brake failure
and possibly a collision. Driving with your foot
resting or riding on the brake pedal can result
in abnormally high brake temperatures,
excessive lining wear, and possible brake
damage. You would not have your full braking
capacity in an emergency.WARNING!
Use only manufacturer's recommended
brake fluid Úpage 444. Using the wrong
type of brake fluid can severely damage
your brake system and/or impair its perfor -
mance. The proper type of brake fluid for
your vehicle is also identified on the original
factory installed hydraulic master cylinder
reservoir.

To avoid contamination from foreign matter
or moisture, use only new brake fluid or fluid
that has been in a tightly closed container.
Keep the master cylinder reservoir cap
secured at all times. Brake fluid in a open
container absorbs moisture from the air
resulting in a lower boiling point. This may
cause it to boil unexpectedly during hard or
prolonged braking, resulting in sudden brake
failure. This could result in a collision.

Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot engine
parts, causing the brake fluid to catch fire.
Brake fluid can also damage painted and
vinyl surfaces, care should be taken to
avoid its contact with these surfaces.
Do not allow petroleum based fluid to
contaminate the brake fluid. Brake seal
components could be damaged, causing
partial or complete brake failure. This could
result in a collision.
WARNING! (Continued)
8

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388SERVICING AND MAINTENANCE
Fluid Level Check — Eight-Speed
Transmission
The fluid level is preset at the factory and does
not require adjustment under normal operating
conditions. Routine fluid level checks are not
required, therefore the transmission has no
dipstick. An authorized dealer can check your
transmission fluid level using special service
tools.
If you notice fluid leakage or transmission
malfunction, visit an authorized dealer
immediately to have the transmission fluid
level checked. Operating the vehicle with
an improper fluid level can cause severe
transmission damage.
Fluid Level Check — Six-Speed
Transmission
It is best to check the fluid level when the
transmission is at normal operating
temperature (158-176°F / 70-80°C). This
normally occurs after at least 15 miles (25 km)
of driving. At normal operating temperature the
fluid cannot be held comfortably between the
fingertips. You can read the transmission sump
temperature in the instrument cluster screen
Ú page 90. Use the following procedure to check the
transmission fluid level properly:

1. Monitor the transmission temperature
using the instrument cluster display, and
operate the vehicle as required to reach
the normal operating temperature. If the
transmission is not functioning properly, or
the vehicle cannot be driven, see the NOTE
and CAUTION below about checking the
fluid level at colder temperatures.

2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60 seconds, and leave the engine
running for the rest of this procedure.
4. Fully apply the parking brake, and press the brake pedal.
5. Place the gear selector momentarily into each gear position (allowing time for the
transmission to fully engage in each
position), ending with the transmission in
PARK.
6. Remove the dipstick, wipe it clean and reinsert it until seated.
CAUTION!
Do not use chemical flushes in your
transmission as the chemicals can damage
your transmission components. Such damage
is not covered by the New Vehicle Limited
Warranty.
CAUTION!

If a transmission fluid leak occurs, visit an
authorized dealer immediately. Severe
transmission damage may occur. An authorized
dealer has the proper tools to adjust the fluid
level accurately.

21_DPF_OM_EN_USC_t.book Page 388

SERVICING AND MAINTENANCE389
7. Remove the dipstick again and note the
fluid level on both sides. The fluid level
reading is only valid if there is a solid
coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full
of fluid if the actual level is at or above the
hole. The fluid level should be between the
“HOT” (upper) reference holes on the
dipstick at normal operating temperature.
If the fluid level is low, add fluid through the
dipstick tube to bring it to the proper level.
Do not overfill. Use ONLY the specified fluid
Ú page 444. After adding any quantity of oil
through the dipstick tube, wait a minimum
of two minutes for the oil to fully drain into
the transmission before rechecking the
fluid level.
NOTE:

If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the
dipstick with the fluid at 60-70°F / 16-21°C. Only
use the COLD region of the dipstick as a rough refer -
ence when setting the fluid level after a transmis -sion service or fluid change. Re-check the fluid level,
and adjust as required, once the transmission
reaches normal operating temperature.

8. Reinsert the dipstick. Check for leaks.
Release the parking brake.
NOTE:

If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two COLD (lower) holes on the dipstick
with the fluid at 68-86°F / 20-30°C. Only use the
COLD region of the dipstick as a rough reference
when setting the fluid level after a transmission
service or fluid change. Re-check the fluid level, and
adjust as required, once the transmission reaches
normal operating temperature.

Fluid And Filter Changes — Eight-Speed
Transmission
Under normal operating conditions, the fluid
installed at the factory will provide satisfactory
lubrication for the life of the vehicle.

Routine fluid and filter changes are not required.
However, change the fluid and filter if the fluid
becomes contaminated (with water, etc.), or if the
transmission is disassembled for any reason.

Fluid And Filter Changes — Six Speed
Transmission
For the proper maintenance intervals
Ú page 354.
In addition, change the fluid and filters if the
fluid becomes contaminated (with water, etc.),
or if the transmission is disassembled for any
reason.
CAUTION!
If the fluid temperature is below 50°F (10°C)
it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough
to produce an accurate reading. Run the
engine at idle, in PARK, to warm the fluid.
CAUTION!
If the fluid temperature is below 50°F (10°C)
it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough
to produce an accurate reading. Run the
engine at idle, in PARK, to warm the fluid.
8

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431
TECHNICAL SPECIFICATIONS
VEHICLE IDENTIFICATION NUMBER (VIN)
The VIN is found on the left front corner of
the instrument panel, visible through the
windshield.
Vehicle Identification Number

NOTE:
It is illegal to remove or alter the VIN.
BRAKE SYSTEM
If power assist is lost for any reason (for
example, repeated brake applications with
the engine off), the brakes will still function.
However, you will experience a substantial
increase in braking effort to stop the vehicle.

If either the front or rear hydraulic system loses
normal braking capability, the remaining system
will still function with some loss of overall braking
effectiveness. This will be evident by increased
pedal travel during application, greater pedal
force required to slow or stop, and activation of
the “Brake Warning Light” and/or the “ABS
Warning Light” during brake use.

HYDRAULIC BRAKE ASSIST — IF
E
QUIPPED
The brake system power assist is provided by a
hydro-boost unit which shares fluid with the
power steering system. You may experience
some clicking or hissing noises from the
hydro-boost system during hard braking
conditions.
NOTE:
Under cold temperatures, pedal effort will be
higher than normal until the power steering fluid
reaches operating temperature.
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444TECHNICAL SPECIFICATIONS
CHASSIS FLUIDS AND LUBRICANTS
6.4L GASOLINE ENGINE
6.7L DIESEL ENGINE
Component Fluid, Lubricant, or Genuine Part
Automatic Transmission – Eight-SpeedUse only Mopar ZF 8&9 Speed ATF Automatic Transmission Fluid, or equivalent. Failure to use
the correct fluid may affect the function or performance of your transmission.
Automatic Transmission – Six-Speed Use only Mopar ASRC Automatic Transmission Fluid or equivalent. Failure to use the proper
fluid may affect the function or performance of your transmission.
Transfer Case We recommend you use Mopar Transfer Case Lubricant for Borg Warner 44-44 and 44-45.
Front and Rear Axle Fluid We recommend you use SAE 75W-85 HD Ram GL-5 Synthetic Axle Lubricant. Limited slip
additive is required for limited slip axles.
Brake Master Cylinder We recommend you use Mopar DOT 3 and SAE J1703.
Power Steering Reservoir
We recommend you use Mopar Power Steering Fluid +4, Mopar ATF+4 Automatic Transmission Fluid.

Component Fluid, Lubricant, or Genuine Part
Automatic TransmissionOnly use Mopar ASRC Automatic Transmission Fluid or equivalent. Failure to use the proper
fluid may affect the function or performance of your transmission.
Transfer Case We recommend you use Mopar BW44–44 Transfer Case Fluid.
Front and Rear Axle Fluid We recommend you use SAE 75W-85 HD Ram GL-5 Synthetic Axle Lubricant. Limited slip
additive is required for limited slip axles.
Brake Master Cylinder We recommend you use Mopar DOT 3 and SAE J1703.

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450
INDEX
 Pair (Link) Uconnect Phone To A Mobile
Phone............................................................ 260 WARRANTY INFORMATION...................... 447
A
Adaptive Cruise Control (ACC)
(Cruise Control)
.................................... 164, 166Adding Engine Coolant (Antifreeze)............... 384Adding Fuel.................................................... 196Additives, Fuel............................................... 434Adjust Down........................................................... 35Forward....................................................... 35Rearward..................................................... 35Up................................................................ 35Adjustable Pedals............................................ 40Advance Phone Connectivity......................... 266Air BagAir Bag Operation...................................... 305Air Bag Warning Light................................ 303Enhanced Accident Response......... 310, 352Event Data Recorder (EDR)....................... 352If Deployment Occurs................................ 309Knee Impact Bolsters................................ 305Maintaining Your Air Bag System.............. 311Maintenance............................................. 311
Redundant Air Bag Warning Light............. 303Transporting Pets..................................... 330Air Bag Light................................ 107, 303, 331Air Cleaner, Engine (Engine Air Cleaner
Filter)................................................... 369, 391Air Conditioner Maintenance........................ 371Air Conditioner Refrigerant.................. 371, 372Air Conditioner System................................. 371Air Conditioning................................................ 62Air Conditioning Filter....................................... 65Air Conditioning System................................... 64Air Conditioning, Operating Tips....................... 65Air Filter........................................................ 369Air PressureTires......................................................... 415AlarmSecurity Alarm....................................23, 108Alterations/ModificationsVehicle......................................................... 10Antifreeze (Engine Coolant).......................... 384Capacities................................................. 439Disposal................................................... 385Anti-Lock Brake System (ABS)...................... 273Anti-Lock Warning Light................................ 113Assist, Hill Start............................................. 280Audio Settings............................................... 253Audio Systems (Radio).................................. 220
Auto Down Power Windows..............................77Automatic Door Locks......................................28Automatic Headlights.......................................52Automatic Temperature Control (ATC)..............64Automatic Transmission....................... 141, 389Adding Fluid.............................................. 389Fluid And Filter Change............................. 389Fluid Change............................................. 389Fluid Level Check............................. 387, 388Fluid Type........................................ 390, 444Shifting..................................................... 146Special Additives...................................... 387Automatic Transmission Limp Home Mode... 145AutoPark....................................................... 120AUX Camera......................................... 188, 194Auxiliary Driving Systems.............................. 281Axle Fluid.....................................390, 391, 444Axle Lubrication................................... 390, 391
B
Back-Up......................................................... 186Back-Up Camera........................................... 186Battery................................................. 108, 366Blanket..................................................... 130Charging System Light.............................. 108Keyless Key Fob Replacement....................16Battery Saver Feature......................................54

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451
Belts, Seat
..................................................... 330Bluetooth Connecting To A Particular Mobile Phone Or Audio Device After Pairing
................262Body Builders Guide........................................ 10Body Mechanism Lubrication........................ 380B-Pillar Location............................................. 411Brake Assist System...................................... 274Brake Control System.................................... 274Brake Fluid.......................................... 387, 444Brake System...................................... 387, 431Fluid Check............................................... 387Master Cylinder......................................... 387Parking...................................................... 137Warning Light............................................ 107Brake/Transmission Interlock....................... 141Bulb Replacement......................................... 401Bulbs, Light.......................................... 332, 401
C
Cab Top Clearance Lights.............................. 405Camera.......................................................... 186Camera, AUX........................................ 188, 194Camera, Rear...................................... 186, 189Capacities, Antifreeze (Engine Coolant)......... 439Capacities, Fluid............................................ 439Caps, FillerOil (Engine)................................................ 364Power Steering.......................................... 163Radiator (Coolant Pressure)...................... 385
Car Washes................................................... 428Carbon Monoxide Warning............................ 333Cargo Light....................................................... 54CD................................................................. 255Cellular Phone.............................................. 269Center High Mounted Stop Light................... 405Center Seat Storage Compartment.................. 67Changing A Flat Tire...................................... 339Charge Air Cooler.......................................... 386Chart, Tire Sizing........................................... 407Check Engine Light (Malfunction
Indicator Light).............................................. 117Checking Your Vehicle For Safety................. 330Checks, Safety.............................................. 330Child Restraint.............................................. 312Child RestraintsBooster Seats........................................... 315Child Seat Installation..................... 323, 325How To Stow An unused ALR Seat Belt.... 322Infant And Child Restraints....................... 313Locating The LATCH Anchorages.............. 320Lower Anchors And Tethers For Children.. 317Older Children And Child Restraints......... 314Seating Positions...................................... 316Clean Air Gasoline......................................... 433CleaningWheels..................................................... 421Climate Control................................................ 58Automatic.................................................... 59Manual........................................................ 62
Cold Weather Operation................................ 122Compact Spare Tire...................................... 419Contract, Service........................................... 446Controls........................................................ 247Cooling Pressure Cap (Radiator Cap)............ 385Cooling System............................................. 383Adding Coolant (Antifreeze)...................... 384Coolant Level................................... 384, 386Cooling Capacity....................................... 439Disposal Of Used Coolant......................... 385Drain, Flush, And Refill............................. 384Inspection................................................. 386Points To Remember................................ 386Pressure Cap............................................ 385Radiator Cap............................................. 385Selection Of Coolant (Antifreeze)..... 384, 440Corrosion Protection..................................... 427Cruise Control (Speed Control)............. 164, 166Cruise Light................................................... 115Customer Assistance.................................... 445Cybersecurity................................................ 220
D
Daytime Running Lights...................................51Dealer Service............................................... 367Defroster, Rear Window...................................62Defroster, Windshield............................ 62, 331Delay (Intermittent) Wipers..............................57Deleting A Phone........................................... 262Diagnostic System, Onboard......................... 116
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