Page 316 of 368

To reduce the risk of personal injury, make sure the engine is
cool before unscrewing the coolant pressure relief cap. The
cooling system is under pressure; steam and hot liquid can come out
forcefully when the cap is loosened slightly.
1. Before you begin, turn the engine off and let it cool.
2. When the engine is cool, wrap a thick cloth around the coolant
pressure relief cap on the coolant reservoir (a translucent plastic bottle).
Slowly turn cap counterclockwise (left) until pressure begins to release.
3. Step back while the pressure releases.
4. When you are sure that all the pressure has been released, use the
cloth to turn it counterclockwise and remove the cap.
5. Fill the coolant reservoir slowly with the proper coolant mixture (see
above), to within the “ cold fill range ” or the “ cold full ” level on the
reservoir. If you removed the radiator cap in an overflow system, fill the
radiator until the coolant is visible and radiator is almost full.
6. Replace the cap. Turn until tightly installed. (Cap must be tightly
installed to prevent coolant loss.)
After any coolant has been added, check the coolant concentration, refer
to Checking Engine Coolant section. If the concentration is not 50/50
(protection to – 34 ° F/ – 36 ° C), drain some coolant and adjust the
concentration. It may take several drains and additions to obtain a 50/50
coolant concentration.
Whenever coolant has been added, the coolant level in the coolant
reservoir should be checked the next few times you drive the vehicle. If
necessary, add enough 50/50 concentration of engine coolant and
distilled water to bring the liquid level to the proper level.
If you have to add more than 1.0 liter (1.0 quart) of engine coolant per
month, have your dealer check the engine cooling system. Your cooling
system may have a leak. Operating an engine with a low level of coolant
can result in engine overheating and possible engine damage.
Recycled engine coolant
Ford Motor Company does NOT recommend the use of recycled engine
coolant in vehicles originally equipped with Motorcraft Premium Gold
Engine Coolant since a Ford-approved recycling process is not yet
available.
Used engine coolant should be disposed of in an appropriate
manner. Follow your community ’ s regulations and standards for recycling
and disposing of automotive fluids.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus)Maintenance and Specifications
316
Page 321 of 368

Fuel Filler Cap
Your fuel tank filler cap has an indexed design with a 1/8 turn on/off
feature.
When fueling your vehicle:
1. Turn the engine off.
2. Carefully turn the filler cap counterclockwise 1/8 of a turn until it
stops.
3. Pull to remove the cap from the fuel filler pipe.
4. To install the cap, align the tabs on the cap with the notches on the
filler pipe.
5. Turn the filler cap clockwise 1/8 of a turn until it stops.
“ CHECK/TIGHTEN FUEL CAP ” will display in the message center when
the fuel filler cap is not properly installed. Proper fuel filler cap
installation is checked automatically as the vehicle is driven, but not until
after some fuel is used (fuel gauge drops below full). Once the fuel filler
cap is properly secured, “ CHECK/TIGHTEN FUEL CAP ” will turn off
after a short period of driving.
If you must replace the fuel filler cap, replace it with a fuel filler
cap that is designed for your vehicle. The customer warranty may
be void for any damage to the fuel tank or fuel system if the
correct genuine Ford or Motorcraft fuel filler cap is not used.
The fuel system may be under pressure. If the fuel filler cap is
venting vapor or if you hear a hissing sound, wait until it stops
before completely removing the fuel filler cap. Otherwise, fuel may
spray out and injure you or others.
If you do not use the proper fuel filler cap, excessive pressure or
vacuum in the fuel tank may damage the fuel system or cause
the fuel cap to disengage in a collision, which may result in possible
personal injury.
Choosing the right fuel
Use only UNLEADED FUEL. The use of leaded fuel is prohibited by law
and could damage your vehicle.
Do not use fuel containing methanol. It can damage critical fuel system
components.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus) Maintenance and Specifications
321
Page 362 of 368

safety belts ..............................302
washing ....................................299
waxing .....................................299
wheels ......................................300
wiper blades ............................301
Clock ..........................................117
Compass, electronic
set zone adjustment ...............138
Console ......................................148
overhead ..........................114 – 116
rear ..........................................149
Controls
power seat ...............................170
steering column ......................129
Coolant
checking and adding ..............313
refill capacities ................317, 349
specifications ..................351, 354
Cruise control
(see Speed control) ..................126
Customer Assistance ................262
Ford accessories for your
vehicle .....................................304
Ford Extended Service
Plan ..........................................292
Getting assistance outside the
U.S. and Canada .....................296
Getting roadside assistance ...262
Getting the service you
need .........................................290
Ordering additional owner ’ s
literature .................................297
The Dispute Settlement
Board .......................................292
Utilizing the
Mediation/Arbitration
Program ...................................295 D
Daytime running lamps
(see Lamps) ..............................100
Defrost
rear window ..............................98
Dipstick
automatic transmission
fluid ..........................................330
engine oil .................................308
Doors
lubricant specifications ..........351
Driveline universal joint and
slip yoke ....................................332
Driving under special
conditions ..................238, 245, 248
sand .........................................247
snow and ice ...........................249
through water .................247, 251
E
Electronic message center .......136
Emergencies, roadside
jump-starting ..........................282
Emission control system ..........326
Engine ........................................354
cleaning ...................................300
coolant .....................................313
fail-safe coolant ......................317
idle speed control ...................311
lubrication
specifications ..................351, 354
refill capacities ........................349
service points ..........................307
starting after a collision .........263
Engine block heater .................220
Engine oil ..................................308
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus)Index
362