The 2020 International Workstar has 31 cooling system parts with verified fitment on this page — 8 part types and 9 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.
On the 2020 International Workstar, 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 31 listed are Coolant / Antifreeze (13 parts), Intercooler Air Hose / Pipe (5 parts) and Thermostat (5 parts). The other 5 part types cover the remaining 8 parts.
The 2020 International Workstar was sold with both the 6.7L L6 DIESEL Turbocharged and the 8.9L L6 DIESEL Turbocharged. 7 parts fit every engine; the other 24 are engine-specific. Each part shows which engine(s) it fits.
9 brands supply cooling system parts for the 2020 International Workstar, led by PRESTONE (7 parts), GATES (6 parts) and VALVOLINE (4 parts), plus 6 more brands. Quality grades include Heavy Duty, Standard Replacement and Economy.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2020 International Workstar. 4 parts have it, including PRESTONE AF3100 (Coolant / Antifreeze) and VALVOLINE ZXG051 (Coolant / Antifreeze). 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: 6.7L L6 DIESEL Turbocharged | AF3055 | 🇺🇸 US 🇨🇦 CA | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: 6.7L L6 DIESEL Turbocharged | AF3100 | 🇺🇸 US 🇨🇦 CA | Prime Yellow - All VehiclesExtended Life | View on Amazon |
| VALVOLINE Fits: 8.9L L6 DIESEL Turbocharged | 719009 | 🇺🇸 US 🇨🇦 CA | Multi-Vehicle Yellow1 Gallon | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: 8.9L L6 DIESEL Turbocharged | ZXG051 | 🇺🇸 US 🇨🇦 CA | G05 Yellow1 Gallon | View on Amazon |
| PEAK Fits: all 2020 Workstar engines | FCA1GAL | 🇺🇸 US 🇨🇦 CA | Fleet Charge1 Gallon | View on Amazon |
| PEAK Fits: all 2020 Workstar engines | FXA1GAL | 🇺🇸 US 🇨🇦 CA | Final Charge Global1 Gallon | View on Amazon |
| PRESTONE Fits: all 2020 Workstar engines | AFC10000 | 🇺🇸 US 🇨🇦 CA | Command ESi PrechargedPurple | View on Amazon |
| PRESTONE Fits: all 2020 Workstar engines | AFC13000 | 🇺🇸 US 🇨🇦 CA | Command COR-Guard Nitrite Free-Noat Extended Life CoolantRed | View on Amazon |
| PRESTONE Fits: all 2020 Workstar engines | AFC12100 | 🇺🇸 US 🇨🇦 CA | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
| VALVOLINE Fits: 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: 6.7L L6 DIESEL Turbocharged | AF2100 | 🇺🇸 US 🇨🇦 CA | All Vehicles10yr/300k mi | View on Amazon |
| PRESTONE Fits: 6.7L L6 DIESEL Turbocharged | AFMAX | 🇺🇸 US 🇨🇦 CA | Max Universal1 Gallon | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Popular Fits: 8.9L L6 DIESEL Turbocharged | ZX001 | 🇺🇸 US 🇨🇦 CA | Original Green1 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 are listed for the 2020 International Workstar, from PRESTONE, VALVOLINE and PEAK. PRESTONE AF3100 carries the "Popular" badge. 5 parts fit every engine; the other 8 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 and VALVOLINE supply 2 parts: the catalog's value-priced group. A representative part number is PRESTONE AF3100.
The Heavy Duty section lists 7 options from PRESTONE, VALVOLINE and PEAK — rated for severe service. VALVOLINE ZXG051 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 ZX001 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 2020 International Workstar — GATES 28436.
Coolant Level Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD Fits: 6.7L L6 DIESEL Turbocharged | 1816403 | 🇺🇸 US 🇨🇦 CA | Aluminum | View on Amazon |
| GPD Fits: 6.7L L6 DIESEL Turbocharged | 1816610 | 🇺🇸 US 🇨🇦 CA | BRASS | View on Amazon |
| GPD Fits: 8.9L L6 DIESEL Turbocharged | 1816611 | 🇺🇸 US 🇨🇦 CA | Cummins ISL 8.9 | 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.
GPD supplies the 3 Coolant Level Sensor parts for the 2020 International Workstar.
Listed part numbers: GPD 1816403, GPD 1816610 and GPD 1816611.
Coolant Reservoir Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: all 2020 Workstar engines | 31405 | 🇺🇸 US 🇨🇦 CA | OE Type | View on Amazon |
| MOTORAD Fits: 8.9L L6 DIESEL Turbocharged | T39 | 🇺🇸 US 🇨🇦 CA | Standard | 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.
2 Coolant Reservoir Cap parts for the 2020 International Workstar come from 2 brands — GATES and MOTORAD. 1 part fits every engine; the other 1 is engine-specific.
Part numbers include GATES 31405 and MOTORAD T39.
Hose Clamp
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2020 Workstar engines | 9044000 | 🇺🇸 US 🇨🇦 CA | 1.75" DiameterCoolant | View on Amazon |
This table covers the Hose clamps.
One part is listed for the 2020 International Workstar — DORMAN 9044000.
Intercooler Air Hose / Pipe
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CONTINENTAL Fits: 8.9L L6 DIESEL Turbocharged | 57504 | 🇺🇸 US 🇨🇦 CA | Convoluted Charge Air | View on Amazon |
| CONTINENTAL Fits: 8.9L L6 DIESEL Turbocharged | 57513 | 🇺🇸 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 |
| GATES Fits: 8.9L L6 DIESEL Turbocharged | 26200 | 🇺🇸 US 🇨🇦 CA | Turbocharger Hose (Ring-Retained)Straight Hose | View on Amazon |
| GATES Fits: 8.9L L6 DIESEL Turbocharged | 26203 | 🇺🇸 US 🇨🇦 CA | Turbocharger Hose (Ring-Retained)4" x 6" (110 psi) | View on Amazon |
This table covers the Intercooler Air Hose pipes.
5 Intercooler Air Hose / Pipe parts are listed for the 2020 International Workstar, from GATES and CONTINENTAL.
Part numbers include CONTINENTAL 57504, CONTINENTAL 57513 and GATES 26201, among others listed above.
Thermostat
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 8.9L L6 DIESEL Turbocharged | 34308 | 🇺🇸 US 🇨🇦 CA | Heavy-Duty | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| 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 Fits: 6.7L L6 DIESEL Turbocharged | 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 |
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.
5 Thermostat parts for the 2020 International Workstar come from 3 brands — MOTORAD, GATES and CALORSTAT.
Heavy Duty: 1 part, from GATES. A representative part number is GATES 34308.
Standard Replacement: 2 parts, from MOTORAD. A representative part number is MOTORAD 407160.
2 further parts sit outside the graded sections, with the same engine-level match.
This group includes GATES 34308, MOTORAD 407160 and MOTORAD 407180 and the remaining parts above.
Water Pump
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 8.9L L6 DIESEL Turbocharged | 9024008 | 🇺🇸 US 🇨🇦 CA | 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.
This group shows a single part: DORMAN 9024008.
Buying Cooling System Parts for a 2020 International Workstar
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 2020 International Workstar?
Our catalog currently lists 31 cooling system parts for the 2020 International Workstar across 8 subcategories and 9 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 2020 International Workstar engines?
Some do. 7 parts fit every engine; the other 24 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 2020 International Workstar?
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 2020 International Workstar 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 2020 International Workstar?
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 2020 International Workstar
Cooling System Parts for Other International Workstar Years
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