25 Cooling system parts are listed for the 2021 Freightliner MT, in 7 part types, covering all 3 engine options (5.1L L4 DIESEL Turbocharged, 6.0L V8 and 6.7L L6 DIESEL Turbocharged). Each one has a brand, a manufacturer part number and notes that say where it fits.
On the 2021 Freightliner MT, 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. 19 parts of the 25 listed are Coolant / Antifreeze (11 parts), Radiator Hose (5 parts) and Thermostat (3 parts). The other 4 part types cover the remaining 6 parts.
The 2021 Freightliner MT was sold with 3 engines. 10 parts fit every engine; the other 15 are engine-specific. Each part shows which engine(s) it fits.
10 brands supply cooling system parts for the 2021 Freightliner MT, led by PRESTONE (7 parts), GATES (5 parts) and CONTINENTAL (3 parts), plus 7 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 MT. 4 parts have it, including PRESTONE AF3100 (Coolant / Antifreeze) and GATES 24232 (Radiator Hose). 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 MT engines | AF3055 | 🇺🇸 US 🇨🇦 CA | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2021 MT engines | AF3100 | 🇺🇸 US 🇨🇦 CA | Prime Yellow - All VehiclesExtended Life | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PEAK Fits: all 2021 MT engines | FCA1GAL | 🇺🇸 US 🇨🇦 CA | Fleet Charge1 Gallon | View on Amazon |
| PEAK Fits: all 2021 MT engines | FXA1GAL | 🇺🇸 US 🇨🇦 CA | Final Charge Global1 Gallon | View on Amazon |
| PRESTONE Fits: all 2021 MT engines | AFC10000 | 🇺🇸 US 🇨🇦 CA | Command ESi PrechargedPurple | View on Amazon |
| PRESTONE Fits: all 2021 MT engines | AFC13000 | 🇺🇸 US 🇨🇦 CA | Command COR-Guard Nitrite Free-Noat Extended Life CoolantRed | View on Amazon |
| PRESTONE Fits: all 2021 MT engines | AFC12100 | 🇺🇸 US 🇨🇦 CA | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
| VALVOLINE Fits: 6.0L V8, 6.7L 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 MT engines | AF2100 | 🇺🇸 US 🇨🇦 CA | All Vehicles10yr/300k mi | View on Amazon |
| PRESTONE Fits: all 2021 MT engines | AFMAX | 🇺🇸 US 🇨🇦 CA | Max Universal1 Gallon | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: 6.0L V8, 6.7L 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.
11 Coolant / Antifreeze parts are listed for the 2021 Freightliner MT, from PRESTONE, PEAK and VALVOLINE. PRESTONE AF3100 carries the "Popular" badge. 9 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 6 options from PRESTONE, PEAK 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: 5.1L L4 DIESEL Turbocharged | 28436 | 🇺🇸 US | 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 MT — GATES 28436.
Coolant Reservoir
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD Fits: 6.0L V8, 6.7L L6 DIESEL Turbocharged | 2421017 | 🇺🇸 US 🇨🇦 CA | Radiator Surge Overflow Tank Assembly | View on Amazon |
This table covers the overflow / expansion tanks that hold extra coolant.
This group shows a single part: GPD 2421017.
Intercooler Air Hose / Pipe
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CONTINENTAL Fits: 6.7L L6 DIESEL Turbocharged | 57512 | 🇺🇸 US 🇨🇦 CA | Convoluted Charge Air | View on Amazon |
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 26201 | 🇺🇸 US 🇨🇦 CA | Turbocharger Hose (Ring-Retained)Straight Hose | View on Amazon |
This table covers the Intercooler Air Hose pipes.
2 Intercooler Air Hose / Pipe parts are listed for the 2021 Freightliner MT, from CONTINENTAL and GATES.
This group includes CONTINENTAL 57512 and GATES 26201.
Radiator
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SPECTRA PREMIUM Fits: 6.0L V8, 6.7L L6 DIESEL Turbocharged | 20011737 | 🇺🇸 US 🇨🇦 CA | All Aluminum Unit | View on Amazon |
| SPECTRA PREMIUM Fits: 6.0L V8, 6.7L L6 DIESEL Turbocharged | 20011737P | 🇺🇸 US 🇨🇦 CA | Aluminum Core with Plastic Tanks | View on Amazon |
This table covers the radiators that dump engine heat to airflow through the core. Typical signs include overheating in traffic, a wet core, or coolant that disappears with no puddle. Replace the cap if it cannot hold the rated pressure, and bleed the system after the swap.
SPECTRA PREMIUM supplies both parts for the 2021 Freightliner MT.
This group includes SPECTRA PREMIUM 20011737 and SPECTRA PREMIUM 20011737P.
Radiator Hose
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Fits: 6.7L L6 DIESEL Turbocharged | 20199S | 🇺🇸 US 🇨🇦 CA | Professional / GoldMolded | View on Amazon |
| CONTINENTAL Fits: 6.7L L6 DIESEL Turbocharged | 60288 | 🇺🇸 US 🇨🇦 CA | Molded | View on Amazon |
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 21571 | 🇺🇸 US 🇨🇦 CA | Molded | View on Amazon |
Universal Hose (Straight, Bulk)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Popular Fits: 6.7L L6 DIESEL Turbocharged | 24232 | 🇺🇸 US 🇨🇦 CA | Straight (Heavy-Duty 2-Ply)2" (60 psi) | View on Amazon |
| CONTINENTAL Fits: 6.7L L6 DIESEL Turbocharged | 57032 | 🇺🇸 US 🇨🇦 CA | Heavy Duty Straight | 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.
5 Radiator Hose parts for the 2021 Freightliner MT come from 3 brands — CONTINENTAL, GATES and ACDELCO. The "Popular" part is GATES 24232.
Standard Replacement: 3 parts, from ACDELCO, CONTINENTAL and GATES. A representative part number is ACDELCO 20199S.
In the Universal Hose (Straight, Bulk) grade, GATES and CONTINENTAL supply 2 parts: grouped under the catalog's "Universal Hose (Straight, Bulk)" designation — the notes column spells out what sets them apart. A representative part number is GATES 24232.
Part numbers include GATES 24232, ACDELCO 20199S and CONTINENTAL 60288, among others listed above.
Thermostat
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CALORSTAT Fits: all 2021 MT engines | TH713082J | 🇺🇸 US 🇨🇦 CA | PerformanceIncludes 1 Rubber Gasket | View on Amazon |
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 33915 | 🇺🇸 US 🇨🇦 CA | OE Type | 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.
3 Thermostat parts for the 2021 Freightliner MT come from 3 brands — CALORSTAT, GATES and MOTORAD. 1 part fits every engine; the other 2 are engine-specific.
Listed part numbers: CALORSTAT TH713082J, GATES 33915 and MOTORAD 923192.
Buying Cooling System Parts for a 2021 Freightliner MT
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 Radiator Hose .
Frequently Asked Questions
How many cooling system parts fit the 2021 Freightliner MT?
Our catalog currently lists 25 cooling system parts for the 2021 Freightliner MT across 7 subcategories and 10 brands, covering all 3 engine options (5.1L L4 DIESEL Turbocharged, 6.0L V8 and 6.7L L6 DIESEL Turbocharged). Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2021 Freightliner MT engines?
Some do. 10 parts fit every engine; the other 15 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 MT?
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 MT 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 MT?
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 MT
Cooling System Parts for Other Freightliner MT Years
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