
For vehicles with overflow coolant systemswith a non-pressurized cap on the coolantrecovery system, add coolant to thecoolant recovery reservoir when the engineis cool. Add prediluted coolant to themaximum level. For all vehicles which havea coolant degas system with a pressurizedcap, or if it is necessary to remove thecoolant pressure relief cap on the radiator,follow these steps to add engine coolant:
1.Turn the engine off and let it cool.
2.Unscrew the cap slowly. Any pressureescapes as you unscrew the cap.
3.Fill the coolant reservoir slowly withprediluted engine coolant to within theminimum and maximum range on theengine coolant reservoir. If youremoved the radiator cap in anoverflow system, fill the radiator untilthe coolant is visible and the radiatoris almost full. If coolant is added tobring the level within the minimum andmaximum range when the engine is notcold, the system may remainunderfilled.
4.Replace the coolant reservoir cap. Turnthe cap clockwise until it contacts thehard stop.
5.Check the coolant level in the coolantreservoir the next few times you driveyour vehicle. If necessary, add enoughprediluted engine coolant to bring thecoolant level to the proper level.
Note:If prediluted coolant is not available,use the approved antifreeze concentratediluting it to 50/50 with distilled water. SeeCooling System Capacity andSpecification (page 302). Using water thathas not been deionized may contribute todeposit formation, corrosion or plugging ofthe small cooling system passageways.
If you have to add more than 1.1 qt (1 L) ofengine coolant per month, have yourvehicle checked as soon as possible.Operating an engine with a low level ofcoolant can result in engine overheatingand possible engine damage.
Note:During normal vehicle operation, thecoolant may change color from orange topink or light red. As long as the coolant isclear and uncontaminated, this color changedoes not indicate the coolant has degradednor does it require the coolant to be drained,the system to be flushed, or the coolant tobe replaced.
Note:In case of emergency, you can add alarge amount of water without coolant inorder to reach a vehicle service location.Water alone, without coolant, can causeengine damage from corrosion, overheatingor freezing. When you reach a servicelocation, you must have the cooling systemdrained, flushed and refilled using thecorrect specification prediluted coolant orantifreeze concentrate. See CoolingSystem Capacity and Specification (page302).
Do not use the following as a coolantsubstitute:
•Alcohol.
•Methanol.
•Brine.
•Any coolant mixed with alcohol ormethanol antifreeze.
Alcohol and other liquids can cause enginedamage from overheating or freezing.
Do not add extra inhibitors or additives tothe coolant. These can be harmful andcompromise the corrosion protection ofthe coolant.
Recycled Coolant
We do not recommend the use of recycledcoolant as an approved recycling processis not yet available.
240
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenance

Dispose of used engine coolant in anappropriate manner. Follow yourcommunity’s regulations and standardsfor recycling and disposing of automotivefluids.
Severe Climates
If you drive in extremely cold climates:
•It may be necessary to increase thecoolant concentration above 50%.
•A coolant concentration of 60%provides improved freeze pointprotection. Coolant concentrationsabove 60% decrease the overheatprotection characteristics of thecoolant and may cause enginedamage.
If you drive in extremely hot climates:
•You can decrease the coolantconcentration to 40%.
•Coolant concentrations below 40%decrease the freeze and corrosionprotection characteristics of thecoolant and may cause enginedamage.
Vehicles driven year-round in non-extremeclimates should use prediluted enginecoolant for optimum cooling system andengine protection.
Coolant Change
Change the coolant at specific mileageintervals as listed in the scheduledmaintenance information. The informationdisplay may display a message to changecoolant at this time. Add predilutedcoolant approved to the correctspecification. See Capacities andSpecifications (page 291).
Engine-driven Cooling Fan (FanClutch)
Your vehicle comes with an engine drivencooling fan drive, also called a fan clutch.This fan drive changes the fan speed tomatch the vehicle’s changing cooling airflow requirements. Fan speed, fan noiselevel and fuel consumption all will increasebased on the driving conditions thatinclude trailer towing, hill climbing, heavyloads, high speed and high ambienttemperature, individually or in combination.
The fan drive is designed to provide theminimum fan speed, and resultingminimum fan noise and fuel consumptionrequired to meet the ever changing vehiclecooling air flow requirements. You will hearthe amount of fan noise increasing anddecreasing as the engine powerrequirements and vehicle driving conditionschange as you drive. This is to be expectedas being normal to the operation of yourvehicle. High levels of fan noise might alsobe heard when your engine is first started,and should normally decrease after drivingfor a short time.
Fail-Safe Cooling
Fail-safe cooling allows you to temporarilydrive your vehicle before any incrementalcomponent damage occurs. The fail-safedistance depends on ambienttemperature, vehicle load and terrain.
How Fail-Safe Cooling Works
If the engine begins to overheat, thecoolant temperature gauge moves towardthe red zone:
A warning lamp illuminates anda message may appear in theinformation display.
241
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenanceE103308 E67028

If the engine reaches a presetover-temperature condition, the engineswitches to alternating cylinder operation.Each disabled cylinder acts as an air pumpand cools the engine.
When this occurs, your vehicle stilloperates, however:
•Engine power is limited.
•The air conditioning system turns off.
Continued operation increases the enginetemperature, causing the engine tocompletely shut down. Your steering andbraking effort increases in this situation.
When the engine temperature cools, youcan re-start the engine. Have your vehiclechecked as soon as possible to minimizeengine damage.
When Fail-Safe Mode Is Activated
WARNING: Fail-safe mode is foruse during emergencies only. Operateyour vehicle in fail-safe mode only aslong as necessary to bring your vehicleto rest in a safe location and seekimmediate repairs. When in fail-safemode, your vehicle will have limitedpower, will not be able to maintainhigh-speed operation, and maycompletely shut down without warning,potentially losing engine power, powersteering assist, and power brake assist,which may increase the possibility of acrash resulting in serious injury.
WARNING: Do not remove thecoolant reservoir cap when the engine ison or the cooling system is hot. Wait 10minutes for the cooling system to cooldown. Cover the coolant reservoir capwith a thick cloth to prevent thepossibility of scalding and slowly removethe cap. Failure to follow this instructioncould result in personal injury.
Your vehicle has limited engine powerwhen in the fail-safe mode, drive yourvehicle with caution. Your vehicle does notmaintain high-speed operation and theengine may operate poorly.
Remember that the engine is capable ofshutting down to prevent engine damage.In this situation:
1.Pull off the road as soon as safelypossible and switch the engine off.
2.If you are a member of a roadsideassistance program, we recommendthat you contact your roadsideassistance service provider.
3.If this is not possible, wait a shortperiod for the engine to cool.
4.Check the coolant level. If the coolantlevel is at or below the minimum mark,add prediluted coolant immediately.
5.When the engine temperature cools,you can re-start the engine. Have yourvehicle checked as soon as possible tominimize engine damage.
Note: Driving your vehicle without repairincreases the chance of engine damage.
Engine Coolant TemperatureManagement (If Equipped)
WARNING: To reduce the risk ofcrash and injury, be prepared that thevehicle speed may reduce and thevehicle may not be able to acceleratewith full power until the coolanttemperature reduces.
If you tow a trailer with your vehicle, theengine may temporarily reach a highertemperature during severe operatingconditions, for example ascending a longor steep grade in high ambienttemperatures.
242
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenance

At this time, you may notice the coolanttemperature gauge moves toward the redzone and a message may appear in theinformation display.
You may notice a reduction in vehiclespeed caused by reduced engine power inorder to manage the engine coolanttemperature. Your vehicle may enter thismode if certain high-temperature andhigh-load conditions take place. Theamount of speed reduction depends onvehicle loading, grade and ambienttemperature. If this occurs, there is noneed to pull off the road. You can continueto drive your vehicle.
The air conditioning may turn on and offduring severe operating conditions toprotect the engine from overheating. Whenthe coolant temperature decreases to thenormal operating temperature, the airconditioning turns on.
If the coolant temperature gauge movesfully into the red zone, or if the coolanttemperature warning or service enginesoon messages appear in your informationdisplay, do the following:
1.Pull off the road as soon as safelypossible and shift the transmission intopark (P).
2.Leave the engine running until thecoolant temperature gauge needlereturns to the normal position. Afterseveral minutes, if the temperaturedoes not drop, follow the remainingsteps.
3.Switch the engine off and wait for it tocool. Check the coolant level.
4.If the coolant level is at or below theminimum mark, add prediluted coolantimmediately.
5.If the coolant level is normal, restartthe engine and continue.
AUTOMATIC TRANSMISSION
FLUID CHECK
The transmission does not consume fluid.However, check the fluid level if thetransmission is not working properly, forexample if the transmission slips, shiftsslowly or if there are signs of fluid loss.
Replace the transmission fluid and filteron your vehicle at the specified serviceinterval. See Scheduled Maintenance(page 325).
Automatic transmission fluid expandswhen warmed. To check the fluid levelconsistently and accurately, do thefollowing:
1.Drive the vehicle until it reaches normaloperating temperature. This may takeup to 20 mi (30 km). Make sure thatthe transmission fluid temperaturegauge on the instrument cluster iswithin normal operating temperature196–215°F (91–102°C) beforechecking.
2.Make sure that your vehicle is on levelground.
3.With the engine running, parking brakeengaged and your foot on the brakepedal, move the gearshift lever throughall of the gear ranges. Allow sufficienttime for each gear to engage.
4.Make sure the parking brake is on. Makesure the transmission is in park (P) orneutral (N) and leave the enginerunning.
5.Open the hood. See Opening andClosing the Hood (page 223).
6.Remove the dipstick and wipe it witha clean, lint-free cloth. See UnderHood Overview (page 225).
7.Replace the dipstick and remove itagain to check the fluid level.
243
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenance

For detailed interval information, seeScheduled Maintenance in your Owner'sManual or your local maintenance guide.
POWER STEERING FLUID
CHECK
Check the power steering fluid. SeeScheduled Maintenance (page 325). Ifadding fluid is necessary, use onlyMERCON LV ATF
Check the fluid level when it is at ambienttemperature.
1.Check the fluid level in the reservoir. Itshould be between the MIN and MAXrange. Do not add fluid if the level iswithin this range.
2.If the fluid level is low, add fluid to bringthe fluid level up to between the MINand MAX range.
3.Switch the engine on.
4.While the engine idles, turn the steeringwheel left and right several times.
5.Switch the engine off.
6.Recheck the fluid level in the reservoir.Do not add fluid if the level is betweenthe MIN and MAX range.
7.If the fluid is low, add the proper typeof fluid in small amounts, continuouslychecking the level until it is betweenthe MIN and MAX range. SeeHydraulic Power Steering FluidCapacity and Specification (page312). Be sure to put the cap back on thereservoir.
CHANGING THE 12V BATTERY
WARNING: This vehicle may beequipped with more than one battery,removal of cable from only one batterydoes not disconnect the vehicleelectrical system. Be sure to disconnectcables from all batteries whendisconnecting power. Failure to do somay cause serious personal injury orproperty damage.
WARNING: Batteries normallyproduce explosive gases which cancause personal injury. Therefore, do notallow flames, sparks or lightedsubstances to come near the battery.When working near the battery, alwaysshield your face and protect your eyes.Always provide proper ventilation.
WARNING: When lifting aplastic-cased battery, excessive pressureon the end walls could cause acid to flowthrough the vent caps, resulting inpersonal injury and damage to thevehicle or battery. Lift the battery with abattery carrier or with your hands onopposite corners.
WARNING: Keep batteries out ofreach of children. Batteries containsulfuric acid. Avoid contact with skin,eyes or clothing. Shield your eyes whenworking near the battery to protectagainst possible splashing of acidsolution. In case of acid contact with skinor eyes, flush immediately with water fora minimum of 15 minutes and get promptmedical attention. If acid is swallowed,call a physician immediately.
Note:If your battery has a cover/shield,make sure it is reinstalled after the batteryhas been cleaned or replaced.
246
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenance

Note:Battery posts, terminals and relatedaccessories contain lead and leadcompounds. Wash hands after handling.
Note:Electrical or electronic accessoriesor components added to the vehicle by thedealer or the owner may adversely affectbattery performance and durability.
Your vehicle is equipped with a Motorcraftmaintenance-free battery which normallydoes not require additional water duringits life of service.
For longer, trouble-free operation, keep thetop of the battery clean and dry. Also,make certain the battery cables are alwaystightly fastened to the battery terminals.
If you see any corrosion on the battery orterminals, remove the cables from theterminals and clean with a wire brush. Youcan neutralize the acid with a solution ofbaking soda and water.
It is recommended that the negativebattery cable terminal be disconnectedfrom the battery if you plan to store yourvehicle for an extended period of time.
Because your vehicle’s engine iselectronically controlled by a computer,some control conditions are maintainedby power from the battery. When thebattery is disconnected or a new batteryis installed, the engine must relearn its idleand fuel trim strategy for optimumdriveability and performance. To begin thisprocess
1.With the vehicle at a complete stop,set the parking brake.
2.Put the gearshift in park (P) or neutral(N) and turn off all accessories.
3.Start the engine. Run the engine untilit reaches normal operatingtemperature.
4.Allow the engine to idle for at least oneminute.
5.Turn the air conditioning (if equipped)on and allow the engine to idle for atleast one minute.
6.Release the parking brake. With yourfoot on the brake pedal and with theair conditioning on, put the vehicle indrive (D) and allow the engine to idlefor at least one minute.
•If you do not allow the engine torelearn its idle trim, the idle qualityof your vehicle may be adverselyaffected until the idle trim iseventually relearned.
7.Drive the vehicle to complete therelearning process
•The vehicle may need to be driven10 mi (16 km) or more to relearn theidle and fuel trim strategy alongwith the ethanol content for flexiblefuel vehicles.
If the battery has been disconnected or anew battery has been installed, the clockand radio settings must be reset once thebattery is reconnected.
Always dispose of automotivebatteries in a responsible manner.Follow your local authorized standardsfor disposal. Call your local authorizedrecycling center to find out more aboutrecycling automotive batteries.
Battery Management System (IfEquipped)
The battery management system (BMS)monitors battery conditions and takesactions to extend battery life. If excessivebattery drain is detected, the system maytemporarily disable certain electricalfeatures to protect the battery. Thoseelectrical accessories affected include therear defrost, heated/cooled seats, climatecontrol fan, heated steering wheel, audioand navigation system. A message may beshown in the information displays to alert
247
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenance

Headlamp bulbs must be marked with anauthorized D.O.T. marking for NorthAmerica to make sure they have the properlamp performance, light brightness, lightpattern and safe visibility.
Install in the reverse order unless otherwisestated.
Headlamp Bulbs
1.Switch all of the lamps and the ignitionoff.
2.Remove the headlamp. SeeRemoving a Headlamp (page 250).
3.Release the clip and remove the bulb.
Note:Do not touch the bulb glass.
Note:If the bulb is accidentally touched, itshould be cleaned with rubbing alcoholbefore being used.
Front Clearance and IdentificationLamp (If Equipped)
1.Switch all of the lamps and the ignitionoff.
2.Remove the screw and lens from thelamp assembly.
3.Press the bulb in and turn the bulbcounterclockwise to remove it.
Brake Lamp, Rear Lamp, RearDirection Indicator, License PlateLamp and Reverse Lamp
1.Switch all of the lamps and the ignitionoff.
2.Remove the four screws and the lamplens from lamp assembly.
3.Remove the bulb by pulling it straightout.
CHANGING THE ENGINE-
MOUNTED AND DIESEL FUEL
CONDITIONER MODULE FUEL
FILTERS - 6.7L DIESEL
WARNING: Do not dispose of fuelin the household refuse or the publicsewage system. Use an authorized wastedisposal facility.
Your vehicle has two fuel filters. The firstfilter mounts on top of the engine on theleft-hand side. The second filter is insidethe diesel fuel conditioner module. Themodule is mounted between the inboardside of the fuel tank and the frame rail.
251
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenanceE163825 E163828

Regular fuel filter changes are animportant part of engine maintenance;failing to keep with the scheduledmaintenance could lead to engineperformance issues and fuel injectionsystem damage. See ScheduledMaintenance (page 325).
Use only recommended service partsconforming to specifications. SeeMotorcraft Parts (page 293).
Note:Using fuel that has high levels ofimpurities may require more frequent filterreplacements than the service intervalspecifies.
Diesel Fuel Conditioner ModuleFilter
Removal
1.Access the underside of your vehicle.
2.The diesel fuel conditioner module ison the left-hand frame rail.
3.Drain the diesel fuel conditionermodule. Turn the drain plugcounterclockwise until it stops. Do notuse any tools to loosen the drain plug.Drain the filter, approximately 0.5 gal(2 L), into an appropriate container.Do not re-use the fuel drained from themodule.
252
2024 F-650/750 (TBC) , enUSA, Edition date: 202210, First-PrintingMaintenanceE250852 E250850 E250851