Service............................................................5-3
Doing Your Own Service Work.........................5-4
Two Safety Cautions about Engine Fan
Breakage...................................................5-5
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
Additives.......................................................5-7
Diesel Engine Fuel.........................................5-8
What Fuel to Use...........................................5-8
Very Cold Weather Operation.........................5-10
Water in Fuel...............................................5-10
Running Out of Fuel.....................................5-15
Fuel Filter Replacement.................................5-15
Fuels in Foreign Countries.............................5-16
Filling Your Tank..........................................5-17
Filling a Portable Fuel Container.....................5-18
Checking Things Under the Hood....................5-18
Hood Latches...............................................5-19
Engine Oil (Caterpillar
®Diesel Engine).............5-20
Engine Oil (Gasoline Engine)..........................5-20
Engine Oil (DURAMAX™ Diesel).....................5-25
Engine Air Cleaner/Filter................................5-30
Automatic Transmission Fluid.........................5-31
Manual Transmission Fluid.............................5-32Engine Coolant (Gas and
DURAMAX™ engines)................................5-32
Engine Coolant (Caterpillar
®Diesel Engines).....5-35
Coolant Surge Tank Pressure Cap..................5-35
Engine Overheating.......................................5-36
Cooling System............................................5-38
Engine Fan Noise.........................................5-43
Power Steering Fluid.....................................5-43
Windshield Washer Fluid................................5-44
Brakes........................................................5-46
Battery........................................................5-55
Jump Starting...............................................5-56
Rear Axle.......................................................5-61
Rear Axle Shift Motor....................................5-61
Noise Control System.....................................5-62
Tampering with Noise Control System
Prohibited.................................................5-62
Bulb Replacement..........................................5-63
Replacement Bulbs.......................................5-63
Windshield Wiper Blade Replacement..............5-63
Other Service Items........................................5-64
Fuel Filter....................................................5-64
Primary Fuel Filter and Water Separator..........5-65
Secondary Fuel Filter and Water
Separator/Heater.......................................5-66
Section 5 Service and Appearance Care
5-1
To inspect the air cleaner/filter, remove the filter from
the vehicle and lightly shake filter to release loose dust
and dirt. If the filter remains “caked” with dirt, a new
filter is required.
{CAUTION:
Operating the engine with the air cleaner/ lter
off can cause you or others to be burned. The
air cleaner not only cleans the air, it helps to
stop ame if the engine back res. If it is not
there and the engine back res, you could
be burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/ lter off.
Notice:If the air cleaner/ lter is off, a back re can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/ lter in place when you
are driving.
Automatic Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. See your Allison Automatic Transmission
Operator’s Manual to find out when to change your
transmission fluid and filters.
How to Check and What to Use
The Allison Automatic Transmission Operator’s Manual
that came with the vehicle shows how to check the
automatic transmission fluid and what fluid to use.
Automatic Transmission External Filter
Your automatic transmission filter requires periodic
replacement.
Consult the Allison Automatic Transmission Operator’s
Manual that came with the vehicle for proper change
intervals.
5-31
Manual Transmission Fluid
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See
Scheduled Maintenance on page 6-5.
Refer to the Maintenance Schedule to determine what
kind of fluid to use. SeePart C: Recommended
Fluids and Lubricants on page 6-29.
When to Check
A good time to have it checked is when the engine oil is
checked. See your Maintenance Schedule to find out
when to change your transmission fluid.
How to Check and What to Use
Check the fluid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest your fingers on the
transmission case.
Then, follow these steps:
1. Remove the filler plug.
2. Check to be sure that the lubricant level is up to the
bottom of the fill opening. On heavy duty
transmissions (an inch of oil level equals about one
gallon of fluid.)
3. If the fluid level is good, install the plug and be sure
it is fully seated. If the fluid level is low, add more
fluid as described in the next steps.
How to Add Fluid
Here’s how to add fluid. Refer to the Maintenance
Schedule to determine the proper fluid to use. SeePart
C: Recommended Fluids and Lubricants on page 6-29.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of the
fill opening.
3. Install the filler plug. Be sure the plug is fully
seated.
Engine Coolant (Gas and
DURAMAX™ engines)
If your vehicle has a Caterpillar®diesel engine, the
Caterpillar®Operation & Maintenance Manual provided
with your vehicle has information regarding the
proper coolant to use.
The cooling system in your vehicle is filled with
DEX-COOL
®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add
only DEX-COOL
®extended life coolant.
5-32
5. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not fully engaged. This improves
fuel economy and reduces fan noise. Under heavy
vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases when the clutch
engages. So you may hear an increase in fan noise.
This is normal and should not be mistaken as thetransmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
Power Steering Fluid
See your Maintenance Schedule for when to check your
power steering fluid.
How To Check Power Steering Fluid
Check your power steering fluid only when the engine is
warm. If the engine isn’t warm, you probably won’t
get an accurate reading.
If the fluid level is between the MIN and MAX marks,
you have enough. If you need fluid, add only enough of
the proper fluid to bring it in between the MIN and
MAX marks.
5-43
Cooling System Capacity
The following approximate capacities are given in English and metric conversions. Please refer toPart C:
Recommended Fluids and Lubricants on page 6-29for more information.
ApplicationCapacities
English Metric
C4/C5 Models
8.1L with manual transmission 30.1 quarts 28.5 liters
8.1L with automatic transmission 29.8 quarts 28.2 liters
6.6L with manual transmission 27.6 quarts 26.1 liters
6.6L with automatic transmission 27.3 quarts 25.8 liters
C6/C7/C8 Models
8.1L with manual transmission 33.3 quarts 31.5 liters
8.1L with manual transmission, air conditioning and
increased cooling34.9 quarts 33.0 liters
8.1L with automatic transmission 32.5 quarts 30.8 liters
7.8L 200–230 hp engine with manual transmission 31.6 quarts 29.9 liters
7.8L 200–230 hp engine with manual transmission, air
conditioning and increased cooling35.3 quarts 33.4 liters
C6/C7/C8 Models
7.8L 200–215 hp engine with automatic transmission 33.7 quarts 31.9 liters
7.2L 175–230 hp engine with manual transmission 29.3 quarts 27.7 liters
5-94
Transmission Fluid Capacity
For manual transmissions, the correct fluid level is to the bottom of the fluid fill plug opening. The fluid capacity will
vary, due to the angle of the transmission, with the vehicle. For automatic transmissions, see the Allison Automatic
Transmission Operator’s Manual for fluid check and maintenance information.
ApplicationCapacities
English Metric
Manual Transmission
ZF S6–650 12.7 pints 6.0 liters
RT6609 12.5 pints 5.9 liters
RT8709B 25.1 pints 11.8 liters
FS4205A, FS4205B, FS4205C 11.1 pints 5.3 liters
FS5205A, FS5205C 11.6 pints 5.5 liters
FS5406 18.4 pints 8.7 liters
FS6305A, FS6305B 18.4 pints 8.7 liters
FS6406 18.4 pints 8.7 liters
FS8406 18.5 pints 8.8 liters
RT8908LL 29.1 pints 13.8 liters
Automatic Transmission
MD 3060 P 52.0 pints 24.6 liters*
MD 3560 P 52.0 pints 24.6 liters*
1000 Series 35.0 pints 13.5 liters*
2000 Series 35.0 pints 13.5 liters*
2200 Series 35.0 pints 13.5 liters*
2400 Series 35.0 pints 13.5 liters*
*Add two pints (one liter) when changing spin-on or remote filter.
5-98
Part C: Recommended Fluids and
Lubricants
Fluids and lubricants identified below by name, part
number or specification may be obtained from your
dealer.
Usage Fluid/Lubricant
Engine Oil
(Gasoline
Engine)Engine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certified for Gasoline Engines
starburst symbol. To determine the
proper viscosity for your vehicle’s
engine, see “Engine Oil” in the
Index.
Engine Oil
(DURAMAX™
Diesel Engine)Engine oil with the letters CI-4 or
CH-4 is best for your vehicle. The
CI-4 or CH-4 designation may
appear either alone or in
combination with other API
designations, such as API CI-4/SL.
These letters show American
Petroleum Institute levels of quality.
To determine the preferred viscosity
for your vehicle’s diesel engine, see
“Engine Oil” in the Index.
Usage Fluid/Lubricant
Engine Oil
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine oil
recommendations.
Engine Coolant
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine
coolant recommendations.
Engine Coolant
(Gasoline
Engine &
DURAMAX™
Diesel)50/50 mixture of clean, drinkable
water and use only
DEX-COOL
®Coolant. See “Engine
Coolant” in the Index.
Hydraulic Brake
SystemDelco Supreme 11 Brake Fluid or
equivalent DOT-3 brake fluid.
Windshield
Washer SolventGM Optikleen
®Washer Solvent.
Clutch Bearing
LubricantClutch Bearing Lubricant (GM Part
No. 12378484 or equivalent NLGI #3
consistency).
Exhaust Brake
Ball Joint Cap
LubricantHigh-Temperature Grease (GM Part
No. U.S. 1051344, in Canada
903037) or NLGI #3 consistency.
Power Steering
SystemDEXRON
®-III Automatic
Transmission Fluid.
6-29
Usage Fluid/Lubricant
Manual
Transmission
(Except ZF
6–Speed)Synthetic Manual Transmission Fluid
(GM Part No. U.S. 12345724, in
Canada 10953510).
Manual
Transmission
(ZF 6–Speed)TranSynd™ Synthetic Transmission
Fluid (GM Part No. U.S. 12378515,
in Canada 88900701).
Automatic
TransmissionSee the Allison
Transmission
®Operator’s Manual for
correct transmission fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Chassis
LubricationChassis Lubricant (GM Part No. U.S.
12377985, in Canada 88901242) or
lubricant meeting requirements of
NLGI #2, Category LB or GC-LB.
Front Wheel
Bearing Grease
(Except Oil
Filled Hubs)Wheel bearing lubricant meeting
requirements of NLGI #2, Category
GC or GC-LB (GM Part No. U.S.
1051344, in Canada 993037).
Usage Fluid/Lubricant
Front Wheel
Bearing Grease
with Oil Filled
HubsSAE 75W-90 Synthetic Axle
Lubricant for Medium Duty Trucks
(GM Part No. U.S. 12345841, in
Canada 10953512t).
Rear Axle and
Rear HubsSAE 75W-90 Synthetic Axle
Lubricant for Medium Duty Trucks
(GM Part No. U.S. 12345841, in
Canada 10953512).
Rear Axle Shift
Motor LubricantRefrigerant Oil (GM Part No.U.S.
5416939, in Canada 10953496).
Propshafts and
SplinesWheel bearing lubricant meeting
requirements of NLGI #2, Category
GC or GC-LB (GM Part No. U.S.
1051344, in Canada 993037).
Cab — Door
Hinges and
LatchesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Weatherstrip
ConditioningDielectric Silicone Grease (GM Part
No. U.S. 12345579, in Canada
992887).
Weatherstrip
SqueaksSynthetic Grease with Teflon,
Superlube (GM Part No. U.S.
12371287, in Canada 10953437).
6-30