
•Do not change the thermostat for Summer or Winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory engine coolant (antifreeze)
performance, poor gas mileage, and increased emis-
sions.
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 turbo-
charger, 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 manifold 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 efficient
burning of fuel resulting in fewer emissions. 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
Brake Master Cylinder — Brake Fluid Level Check
The fluid level of the master cylinder should be checked
when performing under the hood service, or immedi-
ately if the “Brake System Warning Light” indicates
system failure.
The brake master cylinder has a translucent plastic
reservoir. On the outboard side of the reservoir, there is a
“MAX” mark and a “MIN” mark. The fluid level must be
kept within these two marks. Do not add fluid above the
full mark because leakage may occur at the cap.
296 MAINTAINING YOUR VEHICLE 

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, Lubricants, And Genuine Parts” in
“Maintaining Your Vehicle” for further information.
WARNING!
•Use only manufacturer’s recommended brake fluid.
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information.
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.
(Continued)
WARNING! (Continued)
•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 pro-
longed braking, resulting in sudden brake failure.
This could result in a accident.
• 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.
(Continued)
7
MAINTAINING YOUR VEHICLE 297 

WARNING!(Continued)
•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 an accident.
Clutch Hydraulic System
The clutch hydraulic system is a sealed maintenance-free
system. In the event of leakage or other malfunction, the
system must be replaced.
Transfer Case — If Equipped
Drain And Refill
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
Selection of Lubricant
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for fluid specifications.
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.
Manual Transmission — If Equipped
Selection of Lubricant
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for fluid specifications.
Fluid Level Check
The fluid level can be checked by removing the filler
plug. If the level of the lubricant is more than 1/2 in
(12 mm) below the bottom of the filler hole while the
298 MAINTAINING YOUR VEHICLE 

of special dyes for diagnosing fluid leaks. Avoid using
transmission sealers as they may adversely affect seals.
CAUTION!
Do not use chemical flushes in your transmission as
the chemicals can damage your transmission compo-
nents. Such damage is not covered by the New
Vehicle Limited Warranty.
Fluid Level Check
It is best to check the fluid level when the transmission is
at normal operating temperature (170-180°F / 77-82°C for
68RFE transmission, or 158-176°F / 70-80°C for AS69RC
transmission). 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 theEVIC/DID screen (refer to “Electronic Vehicle Informa-
tion Center [EVIC]” or “Driver Information Display
[DID]” for further information).
Use the following procedure to check the transmission
fluid level properly:
1. Monitor the transmission temperature using the
EVIC/DID screen, 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.
300 MAINTAINING YOUR VEHICLE 

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 for 68RFE transmis-
sion, or 68-86°F / 20-30°C for AS69RC transmission. 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.
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. Reinsert the dipstick. Check for leaks. Release the
parking brake.
NOTE: To prevent dirt and water from entering the
transmission after checking or replenishing fluid, make
sure that the dipstick cap is properly reseated. It is
normal for the dipstick cap to spring back slightly from
its fully seated position, as long as its seal remains
engaged in the dipstick tube.
Fluid And Filter Changes
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
In addition, change the fluid and filter(s) if the fluid
becomes contaminated (with water, etc.), or if the trans-
mission is disassembled for any reason.
302 MAINTAINING YOUR VEHICLE 

MAINTENANCE SCHEDULE — DIESEL ENGINE
CAUTION!
Failure to perform the required maintenance items
may result in damage to the vehicle.
At Each Stop For Fuel
Check the engine oil level at least 30 minutes after a fully
warmed engine is shut off. Checking the oil level while
the vehicle is on level ground will improve the accuracy
of the oil level reading. Add oil only when the level is at
or below the ADD or MIN mark.
Once A Month
• Inspect the batteries, and clean and tighten the termi-
nals as required. •
Check the fluid levels of the coolant reservoir, brake
master cylinder, and automatic transmission (if
equipped), and add as needed.
At Each Oil Change
• Change the engine oil filter.
• Inspect the exhaust system.
• Inspect engine air filter.
• Check the coolant level, hoses, and clamps.
• Lubricate outer tie rod ends.
Inspection and service should also be performed anytime
a malfunction is observed or suspected. Retain all re-
ceipts.
Oil Change Indicator System — Cummins Diesel
Your vehicle is equipped with an engine oil change
indicator system. This system will alert you when it is
time to change your engine oil by displaying the words
314 MAINTENANCE SCHEDULE 

Adding Engine Coolant (Antifreeze)............106
Adding Fuel ..............................80
Air Cleaner, Engine (Engine Air Cleaner Filter) .....94
Antifreeze (Engine Coolant) ..................105
Capacities .............................113
Disposal ............................. .108
Automatic Transmission Fluid Type ............................118
Axle Fluid ..............................118
Battery ................................ .103
Brake Fluid ..............................118
Brake System ............................110
Fluid Check ...........................110
Master Cylinder ........................110
Capacities, Antifreeze (Engine Coolant) ..........113
Capacities, Fluid ..........................113 Caps, Filler
Oil (Engine) ............................93
Radiator (Coolant Pressure) ................108
Charge Air Cooler .........................110
Coolant Pressure Cap (Radiator Cap) ...........108
Cooling System .......................... .104
Adding Coolant (Antifreeze) ...............106
Coolant Capacity .......................113
Coolant Level ......................... .104
Disposal Of Used Coolant .................108
Drain, Flush, And Refill ...................105
Points To Remember .....................109
Pressure Cap ......................... .108
Radiator Cap ......................... .108
Selection Of Coolant (Antifreeze) ........105 , 114
Diesel Fuel ...............................73
Diesel Fuel Requirements ....................73
Bulk Storage Of .........................83
326 INDEX - RAM 1500 

Diesel Fuel System, Re-Priming...............101
Disposal Antifreeze (Engine Coolant) ................108
Draining Fuel/Water Separator Filter ............97
Electronic Vehicle Information Center (EVIC) ......25
Engine ..................................90
Air Cleaner ............................94
Block Heater ........................66,73
Break-In Recommendations .................13
Compartment ...........................90
Coolant (Antifreeze) .....................114
Identification ...........................90
Idling ................................70
Oil...............................92,114
Oil Filler Cap ...........................93
Filters Air Cleaner ............................94
Engine Fuel ............................97 Engine Oil
.........................94,114
Engine Oil Disposal ......................94
Fluid Capacities ..........................113
Fluid Level Checks Brake ................................110
Fluid, Brake .............................118
Fluids, Lubricants And Genuine Parts ...........114
Fuel ...................................73
Adding ...............................80
Diesel ............................73,114
Filter .................................97
Requirements ...........................73
Specifications ...........................74
Tank Capacity ..........................113
Fueling .................................80
Gauges Voltmeter ..............................68
8
INDEX - RAM 1500 327