The 2018 Freightliner XB has 26 cooling system parts with verified fitment on this page — 5 part types and 12 brands, covering both the 6.7L L6 DIESEL Turbocharged and the 8.9L L6 DIESEL Turbocharged. Each part includes a manufacturer part number and application notes.
The cooling system system on the 2018 Freightliner XB keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses. The largest groups are Coolant / Antifreeze (13 parts), Water Pump (5 parts) and Thermostat (4 parts). The other 2 part types cover the remaining 4 parts.
The 2018 Freightliner XB was sold with both the 6.7L L6 DIESEL Turbocharged and the 8.9L L6 DIESEL Turbocharged. 14 parts fit every engine; the other 12 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2018 Freightliner XB cooling system parts are PRESTONE (7 parts), VALVOLINE (3 parts) and PEAK (3 parts), plus 9 more brands. Quality grades include Heavy Duty, Standard Replacement and High Volume / Pressure.
4 parts on this 2018 Freightliner XB page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including PRESTONE AF3100 (Coolant / Antifreeze) and MELLING MWP521 (Water Pump). Click any part number to see every vehicle that part fits.
Coolant / Antifreeze
Compatible With All Colors
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Fits: all 2018 XB engines | AF3055 | 🇺🇸 US 🇨🇦 CA | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2018 XB engines | AF3100 | 🇺🇸 US 🇨🇦 CA | Prime Yellow - All VehiclesExtended Life | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: all 2018 XB engines | ZXG051 | 🇺🇸 US 🇨🇦 CA | G05 Yellow1 Gallon | View on Amazon |
| PEAK Fits: all 2018 XB engines | FCA1GAL | 🇺🇸 US 🇨🇦 CA | Fleet Charge1 Gallon | View on Amazon |
| PEAK Fits: all 2018 XB engines | FNA1GAL | 🇺🇸 US 🇨🇦 CA | Final Charge1 Gallon | View on Amazon |
| PEAK Fits: all 2018 XB engines | FXA1GAL | 🇺🇸 US 🇨🇦 CA | Final Charge Global1 Gallon | View on Amazon |
| PRESTONE Fits: all 2018 XB engines | AFC10000 | 🇺🇸 US 🇨🇦 CA | Command ESi PrechargedPurple | View on Amazon |
| PRESTONE Fits: all 2018 XB engines | AFC13000 | 🇺🇸 US 🇨🇦 CA | Command COR-Guard Nitrite Free-Noat Extended Life CoolantRed | View on Amazon |
| PRESTONE Fits: all 2018 XB engines | AFC12100 | 🇺🇸 US 🇨🇦 CA | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
| VALVOLINE Fits: all 2018 XB engines | 846439 | 🇺🇸 US 🇨🇦 CA | HD Nitrite Free Extended Life Yellow1 Gallon | View on Amazon |
Premium
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2018 XB engines | AF2100 | 🇺🇸 US 🇨🇦 CA | All Vehicles10yr/300k mi | View on Amazon |
| PRESTONE Fits: all 2018 XB engines | AFMAX | 🇺🇸 US 🇨🇦 CA | Max Universal1 Gallon | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Fits: all 2018 XB engines | 861399 | 🇺🇸 US 🇨🇦 CA | G40 Pink1 Gallon | View on Amazon |
This table covers the engine coolants and antifreeze formulations specified for this cooling system. Typical signs include a rising temperature gauge, rusty or sludged coolant, or a heater that blows cold. Use the chemistry named in the notes. Mixing silicate, OAT and HOAT formulas can gel in the radiator.
13 Coolant / Antifreeze parts for the 2018 Freightliner XB come from 3 brands — PRESTONE, VALVOLINE and PEAK. The "Popular" part is PRESTONE AF3100. Every part fits both the 6.7L L6 DIESEL Turbocharged and the 8.9L L6 DIESEL Turbocharged.
In the Compatible With All Colors grade, PRESTONE supplies 1 part: grouped under the catalog's "Compatible With All Colors" designation — the notes column spells out what sets them apart. A representative part number is PRESTONE AF3055.
The Economy section lists 1 option from PRESTONE — the catalog's value-priced group. PRESTONE AF3100 is listed in this group.
In the Heavy Duty grade, PEAK, PRESTONE and VALVOLINE supply 8 parts: rated for severe service. A representative part number is VALVOLINE ZXG051.
In the Premium grade, PRESTONE supplies 2 parts: a step above OE specification in materials, tolerances or warranty terms. A representative part number is PRESTONE AF2100.
In the Standard Replacement grade, VALVOLINE supplies 1 part: built to original-equipment specification. A representative part number is VALVOLINE 861399.
Coolant Filter
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WIX Fits: 8.9L L6 DIESEL Turbocharged | 24070 | 🇺🇸 US | Height: 5.214 InCoolant Spin-On Filter | View on Amazon |
| WIX Fits: 8.9L L6 DIESEL Turbocharged | 24084 | 🇺🇸 US | Coolant Spin-On Filter | View on Amazon |
This table covers the Coolant filters. Typical signs include restricted flow — long cranking, weak airflow, or dirty fluid after a short interval. Seat the new filter so it cannot bypass, and use the grade the notes call for.
2 Coolant Filter parts for the 2018 Freightliner XB come from WIX.
Coolant Level Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD Fits: 6.7L L6 DIESEL Turbocharged | 1816403 | 🇺🇸 US | Engine Code ISB 6.7Aluminum | View on Amazon |
| GPD Fits: 6.7L L6 DIESEL Turbocharged | 1816610 | 🇺🇸 US | Engine Code ISB 6.7Brass | View on Amazon |
This table covers the Coolant Level sensors. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors.
2 Coolant Level Sensor parts for the 2018 Freightliner XB come from GPD.
Listed part numbers: GPD 1816403 and GPD 1816610.
Thermostat
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CALORSTAT Fits: all 2018 XB engines | TH713082J | 🇺🇸 US 🇨🇦 CA | PerformanceIncludes 1 Rubber Gasket | View on Amazon |
| MOTORAD Fits: 6.7L L6 DIESEL Turbocharged | 923192 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| MOTORAD Fits: 8.9L L6 DIESEL Turbocharged | 407160 | 🇺🇸 US | Includes Seal | View on Amazon |
| MOTORAD Fits: 8.9L L6 DIESEL Turbocharged | 407180 | 🇺🇸 US | Includes Seal | View on Amazon |
This table covers the thermostats that open the coolant circuit at the specified temperature. Typical signs include slow warm-up, a gauge that climbs in traffic, or heat that never quite arrives. Replace the housing gasket with the thermostat and bleed the system so a trapped air pocket does not cook the new part.
4 Thermostat parts are listed for the 2018 Freightliner XB, from MOTORAD and CALORSTAT. 1 part fits every engine; the other 3 are engine-specific.
Listed part numbers: CALORSTAT TH713082J, MOTORAD 923192 and MOTORAD 407160, plus the other parts above.
Water Pump
High Volume / Pressure
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FVP Fits: 6.7L L6 DIESEL Turbocharged | US7123H | 🇺🇸 US 🇨🇦 CA | B Series New Style ISB Engine | View on Amazon |
| US MOTOR WORKS Fits: 6.7L L6 DIESEL Turbocharged | US7123H | 🇺🇸 US 🇨🇦 CA | B Series New Style ISB Engine | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MELLING Popular Fits: 6.7L L6 DIESEL Turbocharged | MWP521 | 🇺🇸 US 🇨🇦 CA | 7 Vane Plastic Impeller | View on Amazon |
| DAYCO Fits: 6.7L L6 DIESEL Turbocharged | DP1000 | 🇺🇸 US 🇨🇦 CA | Serpentine Belt Driven | View on Amazon |
| GMB Fits: 6.7L L6 DIESEL Turbocharged | 1962420 | 🇺🇸 US 🇨🇦 CA | 94.4 mm Pulley | View on Amazon |
This table covers the pumps that circulate coolant through the block and radiator. Typical signs include coolant at the weep hole, pulley play, or a growl from the front of the engine. Replace the thermostat and refill with the specified coolant whenever the pump comes off.
5 Water Pump parts are listed for the 2018 Freightliner XB, from FVP, US MOTOR WORKS, MELLING and 2 other brands. MELLING MWP521 carries the "Popular" badge.
In the High Volume / Pressure grade, FVP and US MOTOR WORKS supply 2 parts: grouped under the catalog's "High Volume / Pressure" designation — the notes column spells out what sets them apart. A representative part number is FVP US7123H.
The Standard Replacement section: 3 options from MELLING, DAYCO and GMB. MELLING MWP521 is listed in this group.
Part numbers include MELLING MWP521 and FVP US7123H, among others listed above.
Buying Cooling System Parts for a 2018 Freightliner XB
On this vehicle, the cooling system system keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses.
- Match the engine first. Some cooling system parts fit every engine; others are engine-specific. Each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Coolant / Antifreeze and Water Pump .
Frequently Asked Questions
How many cooling system parts fit the 2018 Freightliner XB?
Our catalog currently lists 26 cooling system parts for the 2018 Freightliner XB across 5 subcategories and 12 brands, covering both the 6.7L L6 DIESEL Turbocharged and the 8.9L L6 DIESEL Turbocharged. Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2018 Freightliner XB engines?
Some do. 14 parts fit every engine; the other 12 are engine-specific. Each row (and the filter at the top) shows which. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of cooling system problems on a 2018 Freightliner XB?
Common symptoms include a rising temperature gauge in traffic, sweet-smelling steam, crusty deposits around hose clamps, or a heater that blows cold. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2018 Freightliner XB was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2018 Freightliner XB?
First match the engine — each row shows which engine(s) the part fits. Then replace coolant with the exact specification the manufacturer calls for — mixing chemistries can gel and block small passages. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2018 Freightliner XB
Cooling System Parts for Other Freightliner XB Years
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