10 Cooling system parts are listed for the 2026 International LT, in 5 part types, covering both the 12.7L L6 DIESEL Turbocharged and the 14.9L 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 2026 International LT 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 (4 parts), Intercooler Air Hose / Pipe (3 parts) and Coolant Reservoir Cap (1 part). The other 2 part types cover the remaining 2 parts.
The 2026 International LT was sold with both the 12.7L L6 DIESEL Turbocharged and the 14.9L L6 DIESEL Turbocharged. 6 parts fit every engine; the other 4 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2026 International LT cooling system parts are GATES (5 parts), PRESTONE (4 parts) and SPECTRA PREMIUM (1 part).
Each part number listed for the 2026 International LT opens a page with every vehicle that part fits.
Coolant / Antifreeze
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Fits: all 2026 LT engines | AFC10000 | 🇺🇸 US 🇨🇦 CA | Command ESi PrechargedPurple | View on Amazon |
| PRESTONE Fits: all 2026 LT engines | AFC12100 | 🇺🇸 US 🇨🇦 CA | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
| PRESTONE Fits: all 2026 LT engines | 115CEL | 🇺🇸 US 🇨🇦 CA | Celsius Extended Life Antifreeze or Command ESi Precharged Can1 Gallon | View on Amazon |
| PRESTONE Fits: all 2026 LT engines | 78065 | 🇺🇸 US 🇨🇦 CA | Heavy Duty | 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.
4 Coolant / Antifreeze parts for the 2026 International LT come from PRESTONE. Every part fits both the 12.7L L6 DIESEL Turbocharged and the 14.9L L6 DIESEL Turbocharged.
This group includes PRESTONE AFC10000, PRESTONE AFC12100 and PRESTONE 115CEL and the remaining parts above.
Coolant Reservoir Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: all 2026 LT engines | 31405 | 🇺🇸 US 🇨🇦 CA | 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.
One part is listed for the 2026 International LT — GATES 31405.
Intercooler Air Hose / Pipe
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 12.7L L6 DIESEL Turbocharged | 26201 | 🇺🇸 US 🇨🇦 CA | Turbocharger Hose (Ring-Retained)Straight Hose | View on Amazon |
| GATES Fits: 12.7L 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 | Turbocharger Hose (Ring-Retained)4" x 8" (110 psi) | View on Amazon |
This table covers the Intercooler Air Hose pipes.
3 Intercooler Air Hose / Pipe parts for the 2026 International LT come from GATES.
This group includes GATES 26201, GATES 26203 and GATES 26204.
Radiator
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SPECTRA PREMIUM Fits: all 2026 LT engines | 20013560P | 🇺🇸 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.
This group shows a single part: SPECTRA PREMIUM 20013560P.
Thermostat
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 14.9L L6 DIESEL Turbocharged | 34148 | 🇺🇸 US 🇨🇦 CA | Heavy-Duty | 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.
One part is listed for the 2026 International LT — GATES 34148.
Buying Cooling System Parts for a 2026 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: Coolant / Antifreeze and Intercooler Air Hose / Pipe .
Frequently Asked Questions
How many cooling system parts fit the 2026 International LT?
Our catalog currently lists 10 cooling system parts for the 2026 International LT across 5 subcategories and 3 brands, covering both the 12.7L L6 DIESEL Turbocharged and the 14.9L L6 DIESEL Turbocharged. Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2026 International LT engines?
Some do. 6 parts fit every engine; the other 4 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 2026 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 2026 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 2026 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 2026 International LT
Cooling System Parts for Other International LT Years
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