2020 Ram 2500 air condition

SERVICING AND MAINTENANCE407
Priming If The Engine Has Run Out Of Fuel —
Diesel Engine

1. Add a substantial amount of fuel to the
tank, approximately 2 to 5 gal (8L to 19L).

2. Three priming cycles must be completed. Turn ignition to the RUN position and wait
approximately 30 seconds. This will activate
the in tank fuel pump. Turn the ignition
switch to the off position, and leave off for at
least 30 seconds. Repeat this procedure
three times before cranking the engine.
3. Start the engine using the “Normal Starting” procedure. Refer to “Starting Procedures”
in “Starting and Operating” for further infor -
mation.
4. Once the engine starts, allow the engine to idle for a minimum of 30 seconds. NOTE:
The engine may run rough until the air is forced
from all the fuel lines.
NOTE:
A maximum blend of 5% biodiesel, meeting
ASTM specification D-975 may be used with
your Cummins diesel engine. (Chassis Cab
models not configured with B20 capability.)
A maximum blend of 20% biodiesel, meeting
ASTM specification D-7467 may be used with
your Cummins diesel engine. (Pickup models
and Chassis Cab models configured with B20
capability.)
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 Strategy —
Message Process Flow
The Cummins diesel engine meets all Environ -
mental 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
WARNING!
Do not open the high pressure fuel system
with the engine running. Engine operation
causes high fuel pressure. High pressure fuel
spray can cause serious injury or death.
CAUTION!
Do not engage the starter motor for more
than 15 seconds at a time. Allow two minutes
between the cranking intervals.
WARNING!
Do not use alcohol or gasoline as a fuel
blending agent. They can be unstable under
certain conditions and be hazardous or
explosive when mixed with diesel fuel.
CAUTION!
Due to lack of lubricants in alcohol or
gasoline, the use of these fuels can cause
damage to the fuel system.
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SERVICING AND MAINTENANCE409
Windshield Wiper Blades
Clean the rubber edges of the wiper blades and
the windshield periodically with a sponge or soft
cloth and a mild nonabrasive cleaner. This will
remove accumulations of salt or road film.
Operation of the wipers on dry glass for long
periods may cause deterioration of the wiper
blades. Always use washer fluid when using the
wipers to remove salt or dirt from a dry wind -
shield.
Avoid using the wiper blades to remove frost or
ice from the windshield. Keep the blade rubber
out of contact with petroleum products such as
engine oil, gasoline, etc.
NOTE:
Life expectancy of wiper blades varies
depending on geographical area and frequency
of use. Poor performance of blades may be
present with chattering, marks, water lines or
wet spots. If any of these conditions are
present, clean the wiper blades or replace as
necessary. The wiper blades and wiper arms should be
inspected periodically, not just when wiper
performance problems are experienced. This
inspection should include the following points:
Wear or uneven edges
Foreign material
Hardening or cracking
Deformation or fatigue
If a wiper blade or wiper arm is damaged,
replace the affected wiper arm or blade with a
new unit. Do not attempt to repair a wiper arm
or blade that is damaged.
Wiper Blade Removal/Installation

1. Lift the wiper arm to raise the wiper blade off of the glass, until the wiper arm is in the
full up position.

2. To disengage the wiper blade from the wiper arm, flip up the locking tab.

Wiper Locking Assembly

CAUTION!
Do not allow the wiper arm to spring back
against the glass without the wiper blade in
place or the glass may be damaged.
1 — Wiper
2 — Locking Tab7

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SERVICING AND MAINTENANCE415
(Continued)
Keep the front of the radiator clean. If your
vehicle is equipped with air conditioning,
keep the front of the condenser clean.
Do not change the thermostat for Summer or
Winter operation. If replacement is ever
necessary, install ONLY the correct type ther -
mostat. Other designs may result in unsatis -
factory engine coolant (antifreeze)
performance, poor gas mileage, and
increased emissions.
Charge Air Cooler — Inter-Cooler
The charge air cooler is positioned below the
radiator and the air conditioner condenser. Air
enters the engine through the air cleaner and
passes through the turbocharger, where it is
pressurized. This pressurized air rapidly
reaches high temperature. The air is then
directed through a hose to the charge air cooler
and through another hose to the intake mani -
fold of the engine. The air entering the engine
has been cooled by about 50° to 100°F (10° to
38°C). This cooling process enables more effi -
cient burning of fuel resulting in fewer emis -
sions.
To guarantee optimum performance of the
system, keep the surfaces of the charge air
cooler, condenser and radiator clean and free of debris. Periodically check the hoses leading
to and from the charge air cooler for cracks or
loose clamps resulting in loss of pressure and
reduced engine performance.
Brake System
In order to ensure brake system performance,
all brake system components should be
inspected periodically. Refer to the “Mainte
-
nance Plan” in this section for the proper main -
tenance intervals.
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.
Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information.
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. Refer to “Fluids And Lubri
-
cants” in “Technical Specifications” for
further information. Using the wrong type of
brake fluid can severely damage your brake
system and/or impair its performance. The
proper type of brake fluid for your vehicle is
also identified on the original factory
installed hydraulic master cylinder reser -
voir.
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416SERVICING AND MAINTENANCE
Automatic Transmission
Selection Of Lubricant
It is important to use the proper transmission
fluid to ensure optimum transmission perfor-
mance and life. Use only the manufacturer’s
specified transmission fluid. Refer to “Fluids
And Lubricants” in “Technical Specifications”. It
is important to maintain the transmission fluid
at the correct level using the recommended
fluid. No chemical flushes should be used in any
transmission; only the approved lubricant
should be used.
Special Additives
The manufacturer strongly recommends
against using any special additives in the trans -
mission. 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.
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 immedi
-
ately to have the transmission fluid level
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 reser -
voir 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)
CAUTION!
Using a transmission fluid other than the
manufacturer’s recommended fluid may
cause deterioration in transmission shift
quality and/or torque converter shudder, and
(for six-speed transmissions) will require
more frequent fluid and filter changes. Refer
to “Fluids And Lubricants” in “Technical
Specifications” for fluid specifications.
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.

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SERVICING AND MAINTENANCE419
water, as may be encountered in some
off-highway types of service, will require
draining and refilling the axle to avoid damage.
Limited-Slip Differentials DO REQUIRE limited
slip oil additive (friction modifiers).
NOTE:
Slight noise and mild shuddering may be
evident while turning a vehicle with limited slip
differential on concrete or dry pavement. These
conditions should be considered normal opera -
tion of the limited slip differential.
Transfer Case
Selection Of Lubricant
Use only the manufacturer's recommended
fluid. Refer to “Fluids And Lubricants” in “Tech -
nical Specifications” for further information.
Fluid Level Check
This fluid level can be checked by removing the
filler plug. The fluid level should be to the
bottom edge of the filler plug hole with the
vehicle in a level position.
Drain And Refill
Refer to the “Maintenance Plan” in this section
for the proper maintenance intervals.
Noise Control System Required
Maintenance & Warranty
All vehicles built over 10,000 lbs. (4,535 kg)
Gross Vehicle Weight Rating and manufactured
for sale and use in the United States are
required to comply with the Federal Govern -
ment's Exterior Noise Regulations. These vehi -
cles can be identified by the Noise Emission
Control Label located in the operator's compart -
ment.
Required Maintenance For Noise Control
Systems
The following maintenance services must be
performed every six months or 7,500 miles
(12,000 km) whichever comes first, to ensure
proper operation of the noise control systems.
In addition, inspection and service should be
performed anytime a malfunction is observed or
suspected. Proper maintenance of the entire
vehicle will help the effectiveness of the noise
control systems.
Exhaust System
Inspect the entire exhaust system for leaks and
damaged parts. Devices such as hangers,
clamps, and U-bolts should be tight and in good
condition. Damaged components, burned or
blown out mufflers, burned or rusted out
exhaust pipes should be replaced according to
the procedures and specifications outlined in
the appropriate service manual.
Air Cleaner Assembly
Inspect air cleaner housing for proper assembly
and fit. Make certain that the air cleaner is prop -
erly positioned and that the cover is tight. Check
all hoses leading to the air cleaner for tightness.
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SERVICING AND MAINTENANCE429
Tire Inflation Pressures
The proper cold tire inflation pressure is listed
on the driver's side B-Pillar or rear edge of the
driver's side door.
At least once a month:
Check and adjust tire pressure with a good
quality pocket-type pressure gauge. Do not
make a visual judgement when determining
proper inflation. Tires may look properly
inflated even when they are under-inflated.
Inspect tires for signs of tire wear or visible
damage.
Inflation pressures specified on the placard are
always “cold tire inflation pressure”. Cold tire
inflation pressure is defined as the tire pressure
after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km) after sitting for a minimum of three hours. The cold tire inflation pressure must not exceed the
maximum inflation pressure molded into the
tire sidewall.
Check tire pressures more often if subject to a
wide range of outdoor temperatures, as tire
pressures vary with temperature changes.
Tire pressures change by approximately 1 psi
(7 kPa) per 12°F (7°C) of air temperature
change. Keep this in mind when checking tire
pressure inside a garage, especially in the
Winter.
Example: If garage temperature = 68°F (20°C)
and the outside temperature = 32°F (0°C) then
the cold tire inflation pressure should be
increased by 3 psi (21 kPa), which equals 1 psi
(7 kPa) for every 12°F (7°C) for this outside
temperature condition.
Tire pressure may increase from 2 to 6 psi
(13 to 40 kPa) during operation. DO NOT reduce
this normal pressure build up or your tire pres
-
sure will be too low.
Tire Pressures For High Speed Operation
The manufacturer advocates driving at safe
speeds and within posted speed limits. Where
speed limits or conditions are such that the
vehicle can be driven at high speeds, main -
taining correct tire inflation pressure is very important. Increased tire pressure and reduced
vehicle loading may be required for high-speed
vehicle operation. Refer to an authorized tire
dealer or original equipment vehicle dealer for
recommended safe operating speeds, loading
and cold tire inflation pressures.
Radial Ply Tires
CAUTION!
After inspecting or adjusting the tire pressure,
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the
valve stem, which could damage the valve
stem.
WARNING!
High speed driving with your vehicle under
maximum load is dangerous. The added
strain on your tires could cause them to fail.
You could have a serious collision. Do not
drive a vehicle loaded to the maximum
capacity at continuous speeds above 75 mph
(120 km/h).
WARNING!
Combining radial ply tires with other types of
tires on your vehicle will cause your vehicle to
handle poorly. The instability could cause a
collision. Always use radial ply tires in sets of
four. Never combine them with other types of
tires.
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430SERVICING AND MAINTENANCE
Tire Repair
If your tire becomes damaged, it may be
repaired if it meets the following criteria:
The tire has not been driven on when flat.
The damage is only on the tread section of
your tire (sidewall damage is not repairable).
The puncture is no greater than a ¼ of an
inch (6 mm).
Consult an authorized tire dealer for tire repairs
and additional information.
Damaged Run Flat tires, or Run Flat tires that
have experienced a loss of pressure should be
replaced immediately with another Run Flat tire
of identical size and service description (Load
Index and Speed Symbol). Replace the tire pres -
sure sensor as well as it is not designed to be
reused.
Run Flat Tires — If Equipped
Run Flat tires allow you the capability to drive
50 miles (80 km) at 50 mph (80 km/h) after a rapid loss of inflation pressure. This rapid loss
of inflation is referred to as the Run Flat mode.
A Run Flat mode occurs when the tire inflation
pressure is of/or below 14 psi (96 kPa). Once a
Run Flat tire reaches the run flat mode it has limited driving capabilities and needs to be
replaced immediately. A Run Flat tire is not
repairable. When a run flat tire is changed after
driving with underinflated tire condition, please
replace the TPM sensor as it is not designed to
be reused when driven under run flat mode 14
psi (96 kPa) condition.
NOTE:
TPM Sensor must be replaced after driving the
vehicle on a flat tire condition.
It is not recommended driving a vehicle loaded
at full capacity or to tow a trailer while a tire is in
the run flat mode.
See the tire pressure monitoring section for
more information.
Tire Spinning
When stuck in mud, sand, snow, or ice condi
-
tions, do not spin your vehicle's wheels above
30 mph (48 km/h) or for longer than 30
seconds continuously without stopping.
Refer to “Freeing A Stuck Vehicle” in “In Case Of
Emergency” for further information.
Tread Wear Indicators
Tread wear indicators are in the original equip -
ment tires to help you in determining when your
tires should be replaced.

Tire Tread

WARNING!
Fast spinning tires can be dangerous. Forces
generated by excessive wheel speeds may
cause tire damage or failure. A tire could
explode and injure someone. Do not spin your
vehicle's wheels faster than 30 mph (48 km/h)
for more than 30 seconds continuously when
you are stuck, and do not let anyone near a
spinning wheel, no matter what the speed.
1 — Worn Tire
2 — New Tire

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SERVICING AND MAINTENANCE439
Standard No. 109. Grades B and A repre -
sent higher levels of performance on the
laboratory test wheel, than the minimum
required by law.
STORING THE VEHICLE
If you are storing your vehicle for more than
21 days, we recommend that you take the
following steps to minimize the drain on your
vehicle's battery:
Disconnect the negative cable from battery.
Any time you store your vehicle or keep it out
of service (i.e., vacation) for two weeks or
more, run the air conditioning system at idle
for about five minutes in the fresh air and high blower setting. This will ensure
adequate system lubrication to minimize the
possibility of compressor damage when the
system is started again.
BODYWORK
Protection From Atmospheric Agents
Vehicle body care requirements vary according
to geographic locations and usage. Chemicals
that make roads passable in snow and ice and
those that are sprayed on trees and road
surfaces during other seasons are highly corro
-
sive to the metal in your vehicle. Outside
parking, which exposes your vehicle to airborne
contaminants, road surfaces on which the
vehicle is operated, extreme hot or cold weather
and other extreme conditions will have an
adverse effect on paint, metal trim, and under -
body protection.
The following maintenance recommendations
will enable you to obtain maximum benefit from
the corrosion resistance built into your vehicle.
What Causes Corrosion?
Corrosion is the result of deterioration or
removal of paint and protective coatings from
your vehicle. The most common causes are:
Road salt, dirt and moisture accumulation.
Stone and gravel impact.
Insects, tree sap and tar.
Salt in the air near seacoast localities.
Atmospheric fallout/industrial pollutants.
Body And Underbody Maintenance
Cleaning Headlights
Your vehicle is equipped with plastic headlights
and fog lights that are lighter and less suscep
-
tible to stone breakage than glass headlights.
Plastic is not as scratch resistant as glass and
therefore different lens cleaning procedures
must be followed.
To minimize the possibility of scratching the
lenses and reducing light output, avoid wiping
with a dry cloth. To remove road dirt, wash with
a mild soap solution followed by rinsing.
Do not use abrasive cleaning components,
solvents, steel wool or other aggressive mate -
rial to clean the lenses.
WARNING!
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
under-inflation, or excessive loading, either
separately or in combination, can cause heat
buildup and possible tire failure.
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