This page lists 37 cooling system parts for the 2023 International LT, across 11 part types, covering all 3 engine options (12.4L L6 DIESEL Turbocharged, 12.7L L6 DIESEL Turbocharged and 14.9L L6 DIESEL Turbocharged). Every part shows its brand, manufacturer part number and fitment notes.
On the 2023 International LT, 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. 23 parts of the 37 listed are Thermostat (10 parts), Coolant / Antifreeze (9 parts) and Radiator (4 parts). The other 8 part types cover the remaining 14 parts.
The 2023 International LT was sold with 3 engines. 16 parts fit every engine; the other 21 are engine-specific. Each part shows which engine(s) it fits.
10 brands supply cooling system parts for the 2023 International LT, led by PRESTONE (7 parts), GATES (6 parts) and GPD (5 parts), plus 7 more brands. Quality grades include Standard Replacement, Heavy Duty and Economy.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2023 International LT. 4 parts have it, including PRESTONE AF3100 (Coolant / Antifreeze) and GATES 34148 (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 2023 LT engines | AF3055 | 🇺🇸 US 🇨🇦 CA | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2023 LT engines | AF3100 | 🇺🇸 US 🇨🇦 CA | Prime Yellow - All VehiclesExtended Life | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PEAK Fits: all 2023 LT engines | FCA1GAL | 🇺🇸 US 🇨🇦 CA | Fleet Charge1 Gallon | View on Amazon |
| PEAK Fits: all 2023 LT engines | FXA1GAL | 🇺🇸 US 🇨🇦 CA | Final Charge Global1 Gallon | View on Amazon |
| PRESTONE Fits: all 2023 LT engines | AFC10000 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Command ESi PrechargedPurple | View on Amazon |
| PRESTONE Fits: all 2023 LT engines | AFC13000 | 🇺🇸 US 🇨🇦 CA | Command COR-Guard Nitrite Free-Noat Extended Life CoolantRed | View on Amazon |
| PRESTONE Fits: all 2023 LT engines | AFC12100 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
Premium
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2023 LT engines | AF2100 | 🇺🇸 US 🇨🇦 CA | All Vehicles10yr/300k mi | View on Amazon |
| PRESTONE Fits: all 2023 LT engines | AFMAX | 🇺🇸 US 🇨🇦 CA | Max Universal1 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.
9 Coolant / Antifreeze parts are listed for the 2023 International LT, from PRESTONE and PEAK. PRESTONE AF3100 carries the "Popular" badge. All of them fit every engine offered in the 2023 LT.
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 5 options from PRESTONE and PEAK — 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.
Listed part numbers: PRESTONE AF3100, PRESTONE AF3055 and PEAK FCA1GAL, plus the other parts above.
Coolant Filter
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DONALDSON Fits: 14.9L L6 DIESEL Turbocharged | P550867 | 🇲🇽 MX | Outer Diameter: 93 mm (3.66")Length: 147 mm (5.79") | View on Amazon |
| HASTINGS / BALDWIN Fits: all 2023 LT engines | LOPRI | 🇺🇸 US 🇨🇦 CA | 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 are listed for the 2023 International LT, from DONALDSON and HASTINGS / BALDWIN. 1 part fits every engine; the other 1 is engine-specific.
Part numbers include DONALDSON P550867 and HASTINGS / BALDWIN LOPRI.
Coolant Hose / Pipe
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 12.4L 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 2023 International LT — GATES 28436.
Coolant Reservoir
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2023 LT engines | 6035247 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| GPD Fits: 12.4L L6 DIESEL Turbocharged, 12.7L L6 DIESEL Turbocharged | 2421013 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| GPD Fits: 14.9L L6 DIESEL Turbocharged | 2421012 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the overflow / expansion tanks that hold extra coolant.
3 Coolant Reservoir parts for the 2023 International LT come from 2 brands — GPD and DORMAN. 1 part fits every engine; the other 2 are engine-specific.
Listed part numbers: DORMAN 6035247, GPD 2421013 and GPD 2421012.
Coolant Reservoir Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 12.4L L6 DIESEL Turbocharged, 14.9L L6 DIESEL Turbocharged | 31405 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | OE Type | View on Amazon |
This table covers the caps on the overflow / expansion tank. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable.
This group shows a single part: GATES 31405.
Hose Clamp
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2023 LT engines | 9044000 | 🇺🇸 US 🇨🇦 CA | 1.75" DiameterCoolant | View on Amazon |
This table covers the Hose clamps.
One part is listed for the 2023 International LT — DORMAN 9044000.
Intercooler
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD Fits: all 2023 LT engines | 2711621 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Original Equipment (OE) # 2516097C91 | View on Amazon |
This table covers the intercoolers that cool turbo or supercharger charge air.
One part is listed for the 2023 International LT — GPD 2711621.
Intercooler Air Hose / Pipe
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 12.4L L6 DIESEL Turbocharged | 26200 | 🇺🇸 US 🇨🇦 CA | Turbocharger Hose (Ring-Retained)Straight Hose | View on Amazon |
| GATES Fits: 12.4L L6 DIESEL Turbocharged | 26203 | 🇺🇸 US 🇨🇦 CA | Turbocharger Hose (Ring-Retained)4" x 6" (110 psi) | View on Amazon |
| GATES Fits: 14.9L L6 DIESEL Turbocharged | 26204 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Turbocharger Hose (Ring-Retained)4" x 8" (110 psi) | View on Amazon |
This table covers the Intercooler Air Hose pipes.
GATES supplies the 3 Intercooler Air Hose / Pipe parts for the 2023 International LT.
This group includes GATES 26200, GATES 26203 and GATES 26204.
Radiator
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD Fits: all 2023 LT engines | 9282773 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with 34 In Core Heightwithout Frame | View on Amazon |
| GPD Fits: all 2023 LT engines | 9282774 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Original Equipment (OE) # 2516107C91with 34 In Core Height | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SPECTRA PREMIUM Fits: all 2023 LT engines | 20013560P | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Aluminum Core with Plastic Tanks | View on Amazon |
| SPECTRA PREMIUM Fits: 12.4L L6 DIESEL Turbocharged, 14.9L L6 DIESEL Turbocharged | 20013560 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Aluminum Core / Aluminum Tank | 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.
4 Radiator parts are listed for the 2023 International LT, from GPD and SPECTRA PREMIUM. 3 parts fit every engine; the other 1 is engine-specific.
Economy: 2 parts, from GPD. A representative part number is GPD 9282773.
The Standard Replacement section lists 2 options from SPECTRA PREMIUM — built to original-equipment specification. SPECTRA PREMIUM 20013560P is listed in this group.
This group includes GPD 9282773, GPD 9282774 and SPECTRA PREMIUM 20013560P and the remaining parts above.
Thermostat
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Popular Fits: 14.9L L6 DIESEL Turbocharged | 34148 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Heavy-Duty | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOTORAD Popular Fits: 14.9L L6 DIESEL Turbocharged | 406190 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| CALORSTAT Fits: 14.9L L6 DIESEL Turbocharged | THS1910582 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | PerformanceDoes Not Include Seal | View on Amazon |
| CALORSTAT Fits: 14.9L L6 DIESEL Turbocharged | THS1910588 | 🇺🇸 US 🇨🇦 CA | Does not include seal | View on Amazon |
| MOTORAD Fits: 14.9L L6 DIESEL Turbocharged | 15199 | 🇺🇸 US 🇨🇦 CA | Heavy Duty190 Degrees F, Includes Seal, For Engine Coolant System | 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 | 407825 | 🇺🇸 US 🇨🇦 CA | 225 Degrees Ffor Engine Oil Cooler System | View on Amazon |
| MOTORAD Fits: 14.9L L6 DIESEL Turbocharged | 406180 | 🇺🇸 US 🇨🇦 CA | Includes Seal | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CALORSTAT Fits: 12.4L L6 DIESEL Turbocharged | THS1910582 | 🇺🇸 US 🇨🇦 CA | PerformanceDoes Not Include Seal | View on Amazon |
| CALORSTAT Fits: 12.4L L6 DIESEL Turbocharged, 12.7L L6 DIESEL Turbocharged | THS1910588 | 🇺🇸 US 🇨🇦 CA | Does not include 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.
10 Thermostat parts for the 2023 International LT come from 3 brands — MOTORAD, CALORSTAT and GATES. The "Popular" part is GATES 34148.
Heavy Duty: 1 part, from GATES. A representative part number is GATES 34148.
Standard Replacement: 7 parts, from MOTORAD and CALORSTAT. A representative part number is MOTORAD 406190.
2 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 |
|---|---|---|---|---|
| DORMAN Fits: 14.9L L6 DIESEL Turbocharged | 6745003G | 🇺🇸 US 🇨🇦 CA | Housing to Flange | View on Amazon |
| DORMAN Fits: 14.9L L6 DIESEL Turbocharged | 6745008G | 🇺🇸 US 🇨🇦 CA | Housing to Cylinder Head | 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.
DORMAN supplies both parts for the 2023 International LT.
Listed part numbers: DORMAN 6745003G and DORMAN 6745008G.
Buying Cooling System Parts for a 2023 International LT
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 2023 International LT?
Our catalog currently lists 37 cooling system parts for the 2023 International LT across 11 subcategories and 10 brands, covering all 3 engine options (12.4L L6 DIESEL Turbocharged, 12.7L L6 DIESEL Turbocharged and 14.9L L6 DIESEL Turbocharged). Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2023 International LT engines?
Some do. 16 parts fit every engine; the other 21 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 2023 International LT?
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 2023 International LT 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 2023 International LT?
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 2023 International LT
Cooling System Parts for Other International LT Years
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