The 2021 Ram 4000 has 38 cooling system parts with verified fitment on this page — 9 part types and 12 brands, covering both the 5.7L V8 and the 6.4L V8. Each part includes a manufacturer part number and application notes.
On the 2021 Ram 4000, 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. 27 parts of the 38 listed are Thermostat (13 parts), Coolant / Antifreeze (11 parts) and Thermostat Housing / Water Outlet (3 parts). The other 6 part types cover the remaining 11 parts.
The 2021 Ram 4000 was sold with both the 5.7L V8 and the 6.4L V8. 13 parts fit every engine; the other 25 are engine-specific. Each part shows which engine(s) it fits.
12 brands supply cooling system parts for the 2021 Ram 4000, led by MOTORAD (12 parts), DORMAN (6 parts) and PRESTONE (5 parts), plus 9 more brands. Quality grades include Standard Replacement, Economy and Heavy Duty.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2021 Ram 4000. 6 parts have it, including PRESTONE AF3100 (Coolant / Antifreeze) and MOTORAD 416203 (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 4000 engines | AF3055 | 🇲🇽 MX | Prime YellowAll Vehicles | View on Amazon |
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2021 4000 engines | AF3100 | 🇲🇽 MX | Prime Yellow - All VehiclesExtended Life | View on Amazon |
| VALVOLINE Popular Fits: all 2021 4000 engines | 719009 | 🇲🇽 MX | Multi-Vehicle Yellow1 Gallon | View on Amazon |
| PEAK Fits: all 2021 4000 engines | BQA1GAL | 🇲🇽 MX | Blue Mountain Long LifeAll Vehicle | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Fits: all 2021 4000 engines | AFC12100 | 🇲🇽 MX | Command Nitrite Free Extended Life CoolantYellow Nitrite Free OAT | View on Amazon |
Premium
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PRESTONE Popular Fits: all 2021 4000 engines | AF2100 | 🇲🇽 MX | All Vehicles10yr/300k mi | View on Amazon |
| PEAK Fits: all 2021 4000 engines | PKP1GAL | 🇲🇽 MX | All Vehicles Antifreeze1 Gallon | View on Amazon |
| PEAK Fits: all 2021 4000 engines | PXA1GAL | 🇲🇽 MX | Global Lifetime1 Gallon | View on Amazon |
| PRESTONE Fits: all 2021 4000 engines | AFMAX | 🇲🇽 MX | Max Universal1 Gallon | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| AISIN Fits: all 2021 4000 engines | ACD007 | 🇲🇽 MX | PurpleOAT | View on Amazon |
| PEAK Fits: all 2021 4000 engines | NAP1GAL | 🇲🇽 MX | OET North American Extended Life Purple1 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 Ram 4000, from PRESTONE, PEAK, VALVOLINE and 1 other brand. PRESTONE AF3100 carries the "Popular" badge. All of them fit every engine offered in the 2021 4000.
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, VALVOLINE and PEAK supply 3 parts: the catalog's value-priced group. A representative part number is PRESTONE AF3100.
The Heavy Duty section lists 1 option from PRESTONE — rated for severe service. PRESTONE AFC12100 is listed in this group.
The Premium section lists 4 options from PRESTONE and PEAK — a step above OE specification in materials, tolerances or warranty terms. PRESTONE AF2100 is listed in this group.
The Standard Replacement section lists 2 options from AISIN and PEAK — built to original-equipment specification. AISIN ACD007 is listed in this group.
Coolant Reservoir
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 6.4L V8 | 603840 | 🇲🇽 MX | View on Amazon | |
| GPD Fits: 6.4L V8 | 2411293 | 🇲🇽 MX | View on Amazon |
This table covers the overflow / expansion tanks that hold extra coolant.
2 Coolant Reservoir parts for the 2021 Ram 4000 come from 2 brands — DORMAN and GPD.
This group includes DORMAN 603840 and GPD 2411293.
Radiator
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SPECTRA PREMIUM Fits: 5.7L V8 | CU13494 | 🇲🇽 MX | 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.
One part is listed for the 2021 Ram 4000 — SPECTRA PREMIUM CU13494.
Radiator Fan Blade
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 6.4L V8 | 620057 | 🇲🇽 MX | View on Amazon | |
| GPD Fits: 6.4L V8 | 2812305 | 🇲🇽 MX | Fan Blades Only | View on Amazon |
This table covers the Radiator Fan blades. Typical signs include chatter, streaks, or a skip at the top of the stroke. Confirm left and right lengths in the notes — they are often different.
2 Radiator Fan Blade parts for the 2021 Ram 4000 come from 2 brands — DORMAN and GPD.
Part numbers include DORMAN 620057 and GPD 2812305.
Radiator Fan Shroud
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 6.4L V8 | 620989 | 🇲🇽 MX | Lower | View on Amazon |
| GPD Fits: 6.4L V8 | 2812378 | 🇲🇽 MX | Lower | View on Amazon |
This table covers the shrouds that duct air through the fan and radiator.
2 Radiator Fan Shroud parts are listed for the 2021 Ram 4000, from DORMAN and GPD.
Part numbers include DORMAN 620989 and GPD 2812378.
Temperature Sender / Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 6.4L V8 | 926427 | 🇲🇽 MX | Thread Size: 3/8" | View on Amazon |
| GPD Fits: all 2021 4000 engines | 1712493 | 🇲🇽 MX | with .38"-18" NPTwith 2 Terminal(s) | View on Amazon |
This table covers the senders that report coolant temperature to the gauge or ECU. Typical signs include a gauge that sits on empty or overheat, or a lamp that does not match what the engine is doing. Rule out the cluster and the wiring before replacing the sender.
2 Temperature Sender / Sensor parts are listed for the 2021 Ram 4000, from DORMAN and GPD. 1 part fits every engine; the other 1 is engine-specific.
This group includes DORMAN 926427 and GPD 1712493.
Thermostat
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 6.4L V8 | 9023045 | 🇲🇽 MX | Includes Thermostat and Sensor | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOTORAD Fits: 5.7L V8 | 5416203 | 🇲🇽 MX | Ultra StatIncludes seal | View on Amazon |
| MOTORAD Fits: 5.7L V8 | 5416160 | 🇲🇽 MX | Ultra StatIncludes seal | View on Amazon |
| MOTORAD Fits: 5.7L V8 | 5416180 | 🇲🇽 MX | Ultra StatIncludes seal | View on Amazon |
Performance
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOTORAD Fits: 5.7L V8 | 2416160 | 🇲🇽 MX | High FlowIncludes seal | View on Amazon |
| MOTORAD Fits: 5.7L V8 | 2416180 | 🇲🇽 MX | High FlowIncludes seal | View on Amazon |
| MOTORAD Fits: 5.7L V8 | MRD103 | 🇲🇽 MX | RacingIncludes Thermostat and Seal | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOTORAD Popular Fits: 5.7L V8 | 416203 | 🇲🇽 MX | Includes Seal | View on Amazon |
| MOTORAD Popular Fits: 5.7L V8 | 416180 | 🇲🇽 MX | Includes Seal | View on Amazon |
| MOTORAD Popular Fits: 5.7L V8 | 416160 | 🇲🇽 MX | Includes Seal | View on Amazon |
| CALORSTAT Fits: all 2021 4000 engines | TH713082J | 🇲🇽 MX | PerformanceIncludes 1 Rubber Gasket | View on Amazon |
| MOTORAD Fits: 5.7L V8 | 416192 | 🇲🇽 MX | Includes Seal | View on Amazon |
| MOTORAD Fits: 6.4L V8 | 956216 | 🇲🇽 MX | Includes Thermostat, Housing, and 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 Ram 4000 come from 3 brands — MOTORAD, DORMAN and CALORSTAT. The "Popular" part is MOTORAD 416203. 1 part fits every engine; the other 12 are engine-specific.
The Economy section: 1 option from DORMAN. DORMAN 9023045 is listed in this group.
Heavy Duty: 3 parts, from MOTORAD. A representative part number is MOTORAD 5416203.
The Performance section lists 3 options from MOTORAD — engineered beyond original-equipment specification. MOTORAD 2416160 is listed in this group.
Standard Replacement: 6 parts, from MOTORAD and CALORSTAT. A representative part number is MOTORAD 416203.
Thermostat Housing / Water Outlet
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 5.7L V8 | 902689 | 🇲🇽 MX | Thermostat Housing | View on Amazon |
| SKP Fits: 5.7L V8 | SKCH7689 | 🇲🇽 MX | CoverThermostat Housing | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOTORAD Fits: 5.7L V8 | CH7689 | 🇲🇽 MX | Fits Thermostat Housingor Water Outlet | View on Amazon |
This table covers the housings and outlets the thermostat sits in.
3 Thermostat Housing / Water Outlet parts for the 2021 Ram 4000 come from 3 brands — DORMAN, SKP and MOTORAD.
The Economy section: 2 options from DORMAN and SKP. DORMAN 902689 is listed in this group.
Standard Replacement: 1 part, from MOTORAD. A representative part number is MOTORAD CH7689.
Listed part numbers: DORMAN 902689, SKP SKCH7689 and MOTORAD CH7689.
Water Pump Gasket
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| AJUSA Fits: 5.7L V8 | 01704700 | 🇲🇽 MX | View on Amazon | |
| ELRING Fits: 6.4L V8 | B16430 | 🇲🇽 MX | View on Amazon |
This table covers the gaskets between the water pump and the block or housing. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for.
2 Water Pump Gasket parts are listed for the 2021 Ram 4000, from AJUSA and ELRING.
Listed part numbers: AJUSA 01704700 and ELRING B16430.
Buying Cooling System Parts for a 2021 Ram 4000
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 Ram 4000?
Our catalog currently lists 38 cooling system parts for the 2021 Ram 4000 across 9 subcategories and 12 brands, covering both the 5.7L V8 and the 6.4L V8. Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2021 Ram 4000 engines?
Some do. 13 parts fit every engine; the other 25 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 Ram 4000?
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 Ram 4000 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 Ram 4000?
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 Ram 4000
Cooling System Parts for Other Ram 4000 Years
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