
After replacing the fuel filter, the engine will purge the trapped
air as it runs. The engine may run roughly and smoke until the air
is completely eliminated.
Using a fuel which has more than average impurities may require
the fuel filter to be replaced more frequently than the service
interval specifies.
Fuel filter replacement - Cummins B engine
Refer to your engine operator’s manual for service intervals and procedures.
FUEL CONSUMPTION IMPROVEMENT MEASURES
There are two important factors you can control to improve fuel
economy: the mechanical condition of your vehicle and how you drive it.
A properly maintained vehicle will deliver better performance than a
neglected vehicle. Always follow your maintenance schedule to keep your
vehicle in top operating condition.
Also, your driving habits have a significant influence on use of fuel. By
following these suggestions, you can stretch your fuel use:
•Avoid changes in speed as much as possible.
•Anticipate changing traffic conditions. Sudden stops and fast
acceleration waste fuel.
•Avoid extensive idling.
•Do not drive with your foot resting on the brake pedal.
Essentials of good fuel economy
Measuring techniques
Your best source of information about actual fuel economy is you, the
driver. You must gather information as accurately and consistently as
possible. Fuel expense, frequency of fill-ups or fuel gauge readings are
NOT accurate as a measure of fuel economy. We do not recommend
taking fuel economy measurements during the first 1,600 km (1,000
miles) of driving (engine break-in period). You will get a more accurate
measurement after 3,000 km–5,000 km (2,000 miles-3,000 miles).
The advertised fuel capacity of the fuel tank(s) on your vehicle is equal
to the rated refill capacity of the fuel tank(s) as listed inFuel tanksin
this chapter. The advertised capacity is the amount of the Indicated
Capacity and the Empty Reserve combined. Indicated Capacity is the
difference in the amount of fuel in a full tank and a tank when the fuel
gauge indicates empty. Empty Reserve is the small amount of usable fuel
remaining in the fuel tank after the fuel gauge indicates empty.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
191

The amount of Empty Reserve varies and should not be relied
upon to increase driving range. When refueling your vehicle after
the fuel gauge indicates empty, you might not be able to refuel
the full amount of the advertised capacity of the fuel tank due to
the empty reserve still present in the tank.
Filling the tank
For consistent results:
•Use the same fill rate setting (low—medium—high) each time
during filling.
•Allow three automatic click-offs when filling.
•Always use fuel of a known quality, preferably a national brand.
•Have the vehicle loading and distribution the same every time.
•When refueling a vehicle equipped with dual fuel tanks, if the two
tanks are not filled equally, the fuel gauge reading may fluctuate
slightly until the fuel level between the two tanks balance out and
become equal.
Your results will be most accurate if your filling method is consistent.
Note:For vehicles equipped with dual fuel tanks, engine performance
may degrade if fuel is not added to both tanks when refueling.
Calculating fuel economy
1. Fill the fuel tank(s) completely and record the initial odometer
reading (in kilometers or miles).
2. Each time you fill the tank(s), record the amount of fuel added (in
liters or gallons).
3. After at least three to five tank fill-ups, fill the fuel tank(s) and record
the current odometer reading.
4. Subtract your initial odometer reading from the current odometer
reading.
5. Follow one of the simple calculations in order to determine fuel economy:
•Multiply liters used by 100, then divide by total kilometers traveled.
•Divide total miles traveled by total gallons used.
Keep a record for at least one month and record the type of driving (city
or highway). This will provide an accurate estimate of the vehicle’s fuel
economy under current driving conditions. Additionally, keeping records
during summer and winter will show how temperature impacts fuel
economy. In general, lower temperatures give lower fuel economy.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
192

Driving style—good driving and fuel economy habits
Give consideration to the lists that follow and you may be able to change
a number of variables and improve your fuel economy.
Habits
•Smooth, moderate operation can yield up to 10% savings in fuel.
•Steady speeds without stopping will usually give the best fuel
economy.
•Anticipate stopping; slowing down may eliminate the need to stop.
•Sudden or hard accelerations may reduce fuel economy.
•Slow down gradually.
•Driving at reasonable speeds (traveling at 88 km/h [55 mph] uses 15%
less fuel than traveling at 105 km/h [65 mph]).
•Using the air conditioner or defroster may reduce fuel economy.
•Resting your foot on the brake pedal while driving may reduce fuel
economy.
Conditions
•Carrying unnecessary weight may reduce fuel economy.
•Fuel economy may decrease with lower temperatures during the first
12–16 km (8–10 miles) of driving.
•Flat terrain driving improves fuel economy over hilly roads.
•Transmissions give their best fuel economy when operated in the top
cruise gear and with steady pressure on the accelerator.
•Close windows for highway driving.
NOISE EMISSIONS–EXTERIOR
In order to comply with the federal exterior noise regulations, your
vehicle may be equipped with noise emission items. Depending on the
vehicle configuration, it may have all or some of the following items:
Air Intake System
•Air Cleaner:should be inspected and its location should not be
altered. Do not alter inlet and outlet piping.
Body
•Wheel Well:splash shields, cab shields and under-hood insulation
should be inspected for deterioration, dislocation, and orientation.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
193

Inspect air intake piping
•Check for accumulation of salt deposits (where applicable). If present,
disassemble and clean the complete air intake piping system. If the
intake piping is pitted, use RTV silicone to seal joints against leakage.
•Check for loose hoses and clamps.
•Check for ruptured or collapsed hoses.
•Check air cleaner housing for cracks.
ELECTRICAL SYSTEM INSPECTIONS
Periodically inspect electrical connectors on the outside of the cab, on
the engine and frame for corrosion and tightness. Exposed terminals
such as the fuel sender, cranking motor, alternator and feed-through
studs should be cleaned and re-coated with a lubricant sealing grease
such as Motorcraft XG-3, or equivalent. This should include the ground
cable connector for batteries, engine and cab as well as the jump starting
stud.
Accessory feed connections
Vehicle electrical systems are complex and often include electronic
components such as engine and transmission controls, instrument panels,
ABS, etc. While most systems operate on battery voltage (12 volts),
some systems can be as high as 90 volts or as low as five volts. Refer to
the Electrical Circuit Diagram Manuals, available from your vehicle’s
manufacturer, to assure that any additional body lights and accessories
are connected to circuits that are both appropriate and not overloaded.
No modification should be made to any vehicle control system without
first contacting your dealer.
SUSPENSION INSPECTION
Note:Do not adjust air suspension height to any setting other than the
specified setting. Altering the height setting will change the driveline
angle and may result in unwarrantable component damage, such as
transmission component damage.
Verify drive axle air suspension height and height control valve
performance at engine lube oil change intervals.
Periodically:
•Check condition of spring leaves for evidence of fatigue, bending or
breakage.
•Check condition of suspension mounting brackets and bushings.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
195

LUBRICANT SPECIFICATIONS
Component /
Component vendorLubrication type Vendor
recommendations:
Viscosity / Ambient
temperature / NotesEquivalent Ford
part name / number
Non-driving front axle
Eaton-Spicer axle
(generic) - front
axle wheel bearing
oilMultipurpose EP
gear lube of API
GL-5 quality meeting
MIL-PRF-2105E
specifications
including synthetic*
lubricants. (* Do not
mix conventional
and synthetic
lubricants.)SAE 75W:–40°Cto
–26°C(–40°Fto
–15°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance
Synthetic Rear Axle
Lubricant /
XY-75W90–TQL
SAE 75W-80:–40°C
to 27°C(–40°Fto
80°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance
Synthetic Rear Axle
Lubricant /
XY-75W90–TQL
SAE 75W-90:–40°C
to 38°C(–40°Fto
100°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance
Synthetic Rear Axle
Lubricant /
XY-75W90–TQL
SAE 75W-140:–40°C
and above (–40°F
and above)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance
Synthetic Rear Axle
Lubricant /
XY-75W140–QL
SAE 80W-90:–26°C
to–38°C(–15°Fto
100°F)Motorcraft SAE
80W-90 Premium
Rear Axle Lubricant
/ XY-80W90–QL
SAE 80W-140:–26°C
and above (–15°F
and above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140–QL
SAE 85W-140:–12°C
and above (10°Fand
above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140–QL
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
207

Component /
Component vendorLubrication type Vendor
recommendations:
Viscosity / Ambient
temperature / NotesEquivalent Ford
part name / number
Spicer axle - front
axle wheel bearing
oilMultipurpose EP
gear lube of API
GL-5 quality meeting
MIL-PRF-2105E
specifications
including synthetic*
lubricants.(* Do
not mix
conventional and
synthetic
lubricants.)SAE 75W:–40°Cto
0°C(–40°Fto32°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance
Synthetic Rear Axle
Lubricant /
XY-75W90–TQL
SAE 75W-90:–40°C
to 38°C(–40°Fto
100°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance
Synthetic Rear Axle
Lubricant /
XY-75W90–TQL
SAE 75W-140:–40°C
and above (–40°F
and above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140–QL
SAE 80W:–26°Cto
21°C(–15°Fto
70°F)Motorcraft SAE
80W-90 Premium
Rear Axle Lubricant
/ XY-80W90–QL
SAE 80W-140:–26°C
and above (–15°F
and above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140–QL
SAE 90W:–12°Cto
38°C (10°Fto
100°F)SAE 90 Hypoid Gear
Oil / C6AZ-19580–E
SAE 85W-140:–12°C
and above (10°Fand
above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140–QL
SAE 140W: 4°Cand
above (40°Fand
above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140–QL
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
208

Component /
Component vendorLubrication type Vendor
recommendations:
Viscosity / Ambient
temperature / NotesEquivalent Ford
part name / number
Eaton - single-speed
axlesGeneric lubricant SAE 75W:–40°Cto
–26°C(–40°Fto
–15°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance Axle
Lubricant /
XY-75W90-FEHP
SAE 75W-80:–40°C
to 27°C(–40°Fto
80°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance Axle
Lubricant /
XY-75W90-FEHP
SAE 75W-90:–40°C
to 38°C(–40°Fto
100°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance Axle
Lubricant /
XY-75W90-FEHP
SAE 75W-140:–40°C
and above (–40°F
and above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140-QL
SAE 80W-90:–26°C
to 38°C(–15°Fto
100°F)Motorcraft SAE
80W-90 Premium
Rear Axle Lubricant
/ XY-80W90-QL
SAE 80W-140:–26°C
and above (–15°F
and above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140-QL
SAE 85W-140:–12°C
and above (10°Fand
above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140-QL
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
213

Component /
Component vendorLubrication type Vendor
recommendations:
Viscosity / Ambient
temperature / NotesEquivalent Ford
part name / number
Spicer - single-speed Multipurpose EP
gear lube of API
GL-5 quality meeting
MIL-PRF-2105E
sepcifications
including synthetic
lubricantsSAE 75W:–40°Cto
0°C(–40°Fto32°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance Axle
Lubricant /
XY-75W90-FEHP
SAE 75W-90:–40°C
to 38°C(–40°Fto
100°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance Axle
Lubricant /
XY-75W90-FEHP
SAE 75W-140:–40°C
and above (–40°F
and above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140-QL
SAE 80W:–26°Cto
21°C(–15°Fto
70°F)Motorcraft SAE
75W-90 Fuel
Efficient High
Performance Axle
Lubricant /
XY-75W90-FEHP
SAE 80W-140:–26°C
and above (–15°F
and above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140-QL
SAE 90W:–12°Cto
38°C (10°Fto
100°F)SAE 90 Hypoid Gear
Oil / C6AZ-19580-E
SAE 85W-140:–12°C
and above (10°Fand
above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140-QL
SAE 140W: 4°Cand
above (40°Fand
above)Motorcraft SAE
75W-140 High
Performance Rear
Axle Lubricant /
XY-75W140-QL
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
214