32 Cooling system parts are listed for the 2021 Freightliner XC, in 5 part types, covering all 3 engine options (14.9L L6 DIESEL Turbocharged, 6.7L L6 DIESEL Turbocharged and 8.9L L6 DIESEL Turbocharged). Each one has a brand, a manufacturer part number and notes that say where it fits.
The cooling system system on the 2021 Freightliner XC 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 Thermostat (13 parts), Coolant / Antifreeze (12 parts) and Radiator Hose (4 parts). The other 2 part types cover the remaining 3 parts.
The 2021 Freightliner XC was sold with 3 engines. 10 parts fit every engine; the other 22 are engine-specific. Each part shows which engine(s) it fits.
8 brands supply cooling system parts for the 2021 Freightliner XC, led by PRESTONE (7 parts), CALORSTAT (6 parts) and MOTORAD (6 parts), plus 5 more brands. Quality grades include Heavy Duty, Standard Replacement and Premium.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2021 Freightliner XC. 7 parts have it, including PRESTONE AF3100 (Coolant / Antifreeze) and GATES 34308 (Thermostat). Each part number opens a page with every vehicle that part fits.
Coolant / Antifreeze
Compatible With All Colors
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Fits: all 2021 XC engines | AF3055 | 🇺🇸 US 🇨🇦 CA | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2021 XC engines | AF3100 | 🇺🇸 US 🇨🇦 CA | Prime Yellow - All VehiclesExtended Life | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PEAK Fits: all 2021 XC engines | FCA1GAL | 🇺🇸 US 🇨🇦 CA | Fleet Charge1 Gallon | View on Amazon |
| PEAK Fits: all 2021 XC engines | FNA1GAL | 🇺🇸 US 🇨🇦 CA | Final Charge1 Gallon | View on Amazon |
| PEAK Fits: all 2021 XC engines | FXA1GAL | 🇺🇸 US 🇨🇦 CA | Final Charge Global1 Gallon | View on Amazon |
| PRESTONE Fits: all 2021 XC engines | AFC10000 | 🇺🇸 US 🇨🇦 CA | Command ESi PrechargedPurple | View on Amazon |
| PRESTONE Fits: all 2021 XC engines | AFC13000 | 🇺🇸 US 🇨🇦 CA | Command COR-Guard Nitrite Free-Noat Extended Life CoolantRed | View on Amazon |
| PRESTONE Fits: all 2021 XC engines | AFC12100 | 🇺🇸 US 🇨🇦 CA | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
| VALVOLINE Fits: 6.7L L6 DIESEL Turbocharged, 8.9L L6 DIESEL Turbocharged | 846439 | 🇺🇸 US 🇨🇦 CA | HD Nitrite Free Extended Life Yellow1 Gallon | View on Amazon |
Premium
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2021 XC engines | AF2100 | 🇺🇸 US 🇨🇦 CA | All Vehicles10yr/300k mi | View on Amazon |
| PRESTONE Fits: all 2021 XC engines | AFMAX | 🇺🇸 US 🇨🇦 CA | Max Universal1 Gallon | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: 6.7L L6 DIESEL Turbocharged, 8.9L L6 DIESEL Turbocharged | 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.
12 Coolant / Antifreeze parts are listed for the 2021 Freightliner XC, from PRESTONE, PEAK and VALVOLINE. PRESTONE AF3100 carries the "Popular" badge. 10 parts fit every engine; the other 2 are engine-specific.
The Compatible With All Colors section lists 1 option from PRESTONE — grouped under the catalog's "Compatible With All Colors" designation — the notes column spells out what sets them apart. PRESTONE AF3055 is listed in this group.
In the Economy grade, PRESTONE supplies 1 part: the catalog's value-priced group. A representative part number is PRESTONE AF3100.
The Heavy Duty section lists 7 options from PEAK, PRESTONE and VALVOLINE — rated for severe service. PEAK FCA1GAL is listed in this group.
The Premium section lists 2 options from PRESTONE — a step above OE specification in materials, tolerances or warranty terms. PRESTONE AF2100 is listed in this group.
The Standard Replacement section lists 1 option from VALVOLINE — built to original-equipment specification. VALVOLINE 861399 is listed in this group.
Coolant Hose / Pipe
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 28436 | 🇺🇸 US 🇨🇦 CA | Straight (Heavy-Duty)3/8" | View on Amazon |
This table covers the hard pipes and extra hoses in the coolant circuit.
One part is listed for the 2021 Freightliner XC — GATES 28436.
Radiator Hose
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Fits: 6.7L L6 DIESEL Turbocharged | 20125S | 🇺🇸 US 🇨🇦 CA | Professional / GoldMolded | View on Amazon |
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 21194 | 🇺🇸 US 🇨🇦 CA | Molded | View on Amazon |
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 52118 | 🇺🇸 US 🇨🇦 CA | Molded | View on Amazon |
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 52123 | 🇺🇸 US 🇨🇦 CA | Molded | View on Amazon |
This table covers the upper, lower and connecting hoses between radiator, engine and reservoir. Typical signs include swelling, cracks, a soft spot, or a leak at a clamp. Replace adjacent aged hoses while the system is drained — they share the same heat cycle.
4 Radiator Hose parts for the 2021 Freightliner XC come from 2 brands — GATES and ACDELCO.
This group includes ACDELCO 20125S, GATES 21194 and GATES 52118 and the remaining parts above.
Thermostat
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Popular Fits: 8.9L L6 DIESEL Turbocharged | 34308 | 🇺🇸 US 🇨🇦 CA | Heavy-Duty | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CALORSTAT Popular Fits: 8.9L L6 DIESEL Turbocharged | TH713082J | 🇺🇸 US 🇨🇦 CA | PerformanceIncludes 1 Rubber Gasket | View on Amazon |
| CALORSTAT Fits: 8.9L L6 DIESEL Turbocharged | THS1910582 | 🇺🇸 US 🇨🇦 CA | PerformanceDoes Not Include Seal | View on Amazon |
| CALORSTAT Fits: 8.9L L6 DIESEL Turbocharged | THS1910588 | 🇺🇸 US 🇨🇦 CA | Does not include seal | View on Amazon |
| MOTORAD Fits: 8.9L L6 DIESEL Turbocharged | 407160 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| MOTORAD Fits: 8.9L L6 DIESEL Turbocharged | 407180 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CALORSTAT Popular Fits: 14.9L L6 DIESEL Turbocharged, 6.7L L6 DIESEL Turbocharged | TH713082J | 🇺🇸 US 🇨🇦 CA | PerformanceIncludes 1 Rubber Gasket | View on Amazon |
| MOTORAD Popular Fits: 14.9L L6 DIESEL Turbocharged | 406190 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| CALORSTAT Fits: 14.9L L6 DIESEL Turbocharged, 6.7L L6 DIESEL Turbocharged | THS1910582 | 🇺🇸 US 🇨🇦 CA | PerformanceDoes Not Include Seal | View on Amazon |
| CALORSTAT Fits: 14.9L L6 DIESEL Turbocharged, 6.7L L6 DIESEL Turbocharged | THS1910588 | 🇺🇸 US 🇨🇦 CA | Does not include seal | View on Amazon |
| MOTORAD Fits: 14.9L L6 DIESEL Turbocharged | 406160 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| MOTORAD Fits: 14.9L L6 DIESEL Turbocharged | 406180 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| MOTORAD Fits: 6.7L L6 DIESEL Turbocharged | 923192 | 🇺🇸 US 🇨🇦 CA | 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.
13 Thermostat parts for the 2021 Freightliner XC come from 3 brands — CALORSTAT, MOTORAD and GATES. The "Popular" part is GATES 34308.
Heavy Duty: 1 part, from GATES. A representative part number is GATES 34308.
Standard Replacement: 5 parts, from CALORSTAT and MOTORAD. A representative part number is CALORSTAT TH713082J.
7 further parts sit outside the graded sections, with the same engine-level match.
Thermostat / Thermostat Housing / Water Outlet Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DAYTON Fits: 14.9L L6 DIESEL Turbocharged | 6745008G | 🇺🇸 US 🇨🇦 CA | Housing to Cylinder Head | View on Amazon |
| DAYTON Fits: 14.9L L6 DIESEL Turbocharged | 6745003G | 🇺🇸 US 🇨🇦 CA | Housing to Flange | View on Amazon |
This table covers the seals at the thermostat housing and water outlet. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
DAYTON supplies both parts for the 2021 Freightliner XC.
This group includes DAYTON 6745008G and DAYTON 6745003G.
Buying Cooling System Parts for a 2021 Freightliner XC
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: Thermostat and Coolant / Antifreeze .
Frequently Asked Questions
How many cooling system parts fit the 2021 Freightliner XC?
Our catalog currently lists 32 cooling system parts for the 2021 Freightliner XC across 5 subcategories and 8 brands, covering all 3 engine options (14.9L L6 DIESEL Turbocharged, 6.7L L6 DIESEL Turbocharged and 8.9L L6 DIESEL Turbocharged). Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2021 Freightliner XC engines?
Some do. 10 parts fit every engine; the other 22 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 2021 Freightliner XC?
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 2021 Freightliner XC 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 2021 Freightliner XC?
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 2021 Freightliner XC
Cooling System Parts for Other Freightliner XC Years
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