Low Coolant Warning Light............................3-35
Wait to Start Light........................................3-35
Malfunction Indicator Lamp.............................3-36
Oil Pressure Gage........................................3-38
Low Oil Level Light.......................................3-39
Change Engine Oil Light................................3-39
Engine Overspeed Warning Light....................3-40
Engine Shutdown Warning Light.....................3-40
Transmission Temperature Gage.....................3-40
Exhaust Brake Indicator Light.........................3-41
Differential Lock Indicator Light.......................3-41
Reduced Engine Power Light.........................3-42
Highbeam On Light.......................................3-42
Daytime Running Lamps (DRL)
Indicator Light...........................................3-42
Low Washer Fluid Warning Light.....................3-43
Power Take-Off Light (PTO)...........................3-43Check Gages Warning Light...........................3-43
Fuel Gage...................................................3-44
Water in Fuel Warning Light...........................3-45
Change Fuel Filter Warning Light....................3-45
Diesel Particulate Filter Warning Light..............3-46
Air Filter Restriction Indicator..........................3-46
Air Pressure Gage........................................3-47
Hourmeter Gage...........................................3-47
Audio System(s).............................................3-48
Setting the Clock..........................................3-48
Radio(s)......................................................3-49
Theft-Deterrent Feature..................................3-57
Radio Reception...........................................3-58
Fixed Mast Antenna......................................3-58
Chime Level Adjustment................................3-58
Section 3 Instrument Panel
3-2
Service............................................................5-3
Accessories and Modifications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-5
Engine Fan Breakage.....................................5-6
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-7
Additives.......................................................5-7
Diesel Engine Fuel.........................................5-8
What Fuel to Use...........................................5-8
Very Cold Weather Operation.........................5-11
Water in Fuel...............................................5-11
Running Out of Fuel.....................................5-17
Fuel Filter Replacement.................................5-18
Fuels in Foreign Countries.............................5-19
Filling the Tank............................................5-20
Filling a Portable Fuel Container.....................5-22
Checking Things Under the Hood....................5-22
Hood Latches...............................................5-23
Engine Oil (DURAMAX Diesel Engine).............5-24
Engine Oil (Caterpillar Diesel Engine)..............5-27
Engine Oil (Isuzu Diesel Engine).....................5-28
Engine Oil (Gasoline Engine)..........................5-32
Engine Oil Life System (Gasoline Engine)........5-35Engine Oil Life System (DURAMAX/Isuzu
Diesel Engines).........................................5-36
Engine Oil Life System (Caterpillar
Diesel Engine)..........................................5-38
Engine Air Cleaner/Filter................................5-38
Automatic Transmission Fluid.........................5-42
Manual Transmission Fluid.............................5-42
Cooling System............................................5-43
Engine Coolant (Caterpillar Diesel Engines)......5-47
Coolant Surge Tank Pressure Cap..................5-47
Engine Overheating.......................................5-48
Engine Fan Noise.........................................5-49
Power Steering Fluid.....................................5-49
Windshield Washer Fluid................................5-50
Brakes........................................................5-52
Battery........................................................5-61
Jump Starting...............................................5-62
Rear Axle.......................................................5-67
Rear Axle Shift Motor....................................5-68
Four-Wheel Drive............................................5-68
Front Axle......................................................5-69
Noise Control System.....................................5-70
Tampering with Noise Control System
Prohibited.................................................5-70
Bulb Replacement..........................................5-71
Section 5 Service and Appearance Care
5-1
Automatic Transmission Fluid
When to Check
A good time to check your automatic transmission fluid
level 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.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. Refer to the Maintenance Schedule to find out
when to check and change your manual transmission
fluid. SeeScheduled Maintenance on page 6-5.
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.
To check the transmission fluid level, do the following:
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, reinstall the plug and be
sure it is fully seated. If the fluid level is low, add
more fluid as described in the next steps. Refer to
the Maintenance Schedule to determine what
kind of fluid to use. SeePart C: Recommended
Fluids and Lubricants on page 6-31.
5-42
How to Add Fluid
To add transmission fluid, do the following:
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. Refer to the Maintenance Schedule
to determine the proper fluid to use. SeePart
C: Recommended Fluids and Lubricants on
page 6-31.
3. Reinstall the filler plug. Be sure the plug is fully
seated.
Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Engine Fan
B. Coolant Surge Tank
If your vehicle has a Caterpillar
®diesel engine, see the
Caterpillar®Diesel Engine Operation and Maintenance
Manual provided with your vehicle.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface.
5-43
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in N (Neutral)
while stopped. If it is safe to do so, pull off the
road, shift to P (Park) or N (Neutral) and let
the engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
3. If climbing a hill, downshift to raise engine and fan
speeds.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can push down the
accelerator until the engine speed is about twice as
fast as normal idle speed for at least three minutes while
you are parked. If you still have the warning, turn off
the engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.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 the
transmission 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
SeeScheduled Maintenance on page 6-5to determine
when to check your power steering fluid.
5-49
Capacities and Specifications
The following approximate capacities are given in English and metric conversions. SeePart C: Recommended Fluids
and Lubricants on page 6-31for more information.
ApplicationCapacities
English Metric
Air Conditioning Refrigerant R134aFor the air conditioning system refrigerant charge
amount, see the refrigerant caution label located
under the hood. See your dealer/retailer for more
information.
Cooling System – C4/C5 Models
6.6L V8 Automatic Transmission 27.9 qt 26.4 L
8.1L V8 Automatic Transmission 29.8 qt 28.2 L
8.1L V8 Manual Transmission 30.1 qt 28.5 L
Cooling System – C6/C7/C8 Automatic Transmission
7.2L L6 Engine 32.0 qt 30.2 L
Isuzu 6H Engine (207 - 275 hp) 34.8 qt 32.9 L
Isuzu 6H Engine (300 hp) 33.9 qt 32.1 L
8.1L V8 Engine 32.5 qt 30.8 L
5-102
ApplicationCapacities
English Metric
Rear Axle – Two-Speed
19060T (HPL), 22060T (HPH) 38.0 pt 18.0 L
21060T (H15) 38.0 pt 18.0 L
23082T (H25) 44.0 pt 20.8 L
26080T (GJ4) 44.0 pt 20.8 L
Transfer Case (Four-Wheel Drive) 4.0 pt 1.9 L
Transmission Fluid, Automatic
3000 RDS and EVS, and 3500 RDS and EVS with PTO
Provision59.0 pt 28.1 L
3000 RDS and EVS, and 3500 RDS and EVS without PTO
Provision52.0 pt 24.6 L
1000 HS, RDS, MH, PTS and EVS, 2200 HS, RDS, MH,
PTS and EVS, 2500 HS and RDS, and 2300 HS and RDS35.0 pt 16.5 L
Add 2 pints (1 L) when changing spin-on or remote filter.
See the Allison
®Automatic Transmission Operator’s Manual for fluid check and maintenance information.
5-106
ApplicationCapacities
English Metric
Transmission Fluid, Manual
ES052-7, ES066-7 22.0 pt 10.4 L
FS5205A 12.5 pt 5.9 L
FSO8406, FS6305A, FS6305B, FS6406, FS5406A 19.5 pt 9.2 L
FS4205A, FS4205B 11.5 pt 5.4 L
RT6609 12.0 pt 5.7 L
RT8709 26.0 pt 12.3 L
RT8908LL 28.0 pt 13.2 L
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck the fluid level after filling.
Engine Specifications
Engine RPO Type
6.6L V8 DURAMAX®LMM Common Rail Fuel System
7.2L L6 Caterpillar
®C7 LF6Hydraulic/Electronic Unit Injector
Fuel System
7.8L L6 Isuzu 6H LF8 Common Rail Fuel System
8.1L V8 VORTEC™ L18Single Port Fuel Injector Fuel
System
5-107