Dorman 603-5403 Coolant Reservoir
Confirm Fitment Before You Buy
Not sure it fits? Message Year/Make/Model/Engine (2WD/4WD if applicable) and we’ll help confirm compatibility.
Why buy from Koskowski Automotive?
• 50+ years (since 1972) • Dorman Authorized Seller • Fast shipping • Easy returns
Regular price
$224.13
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Vehicle Fitment: Use the table below to match your exact configuration. If you don’t see your exact setup, message us before ordering.
Product Description
This replacement engine coolant reservoir is manufactured from quality materials to withstand the stresses of underhood heat and engine vibration. It is engineered and manufactured to match the fit and function of the original part.
- Direct replacement - this engine coolant reservoir matches the fit and function of the original part
- Ideal solution - engineered for a seamless installation
- Durable construction - manufactured from quality materials to withstand underhood heat and vibration
- Trustworthy design - backed by 100 years of automotive aftermarket experience
Detailed Applications
| Year | Make | Model | Configuration | Positions | Application Notes |
|---|---|---|---|---|---|
| 2024 | Kenworth | W900 | w/BEHR Cooling Module | ||
| 2023 | Kenworth | W900 | w/BEHR Cooling Module | ||
| 2023 | Peterbilt | 365 | w/BEHR Cooling Module | ||
| 2023 | Peterbilt | 367 | w/BEHR Cooling Module | ||
| 2023 | Peterbilt | 389 | w/BEHR Cooling Module | ||
| 2022 | Kenworth | T800 | w/BEHR Cooling Module | ||
| 2022 | Kenworth | W900 | w/BEHR Cooling Module | ||
| 2022 | Peterbilt | 365 | w/BEHR Cooling Module | ||
| 2022 | Peterbilt | 367 | w/BEHR Cooling Module | ||
| 2022 | Peterbilt | 389 | w/BEHR Cooling Module | ||
| 2021 | Kenworth | T800 | w/BEHR Cooling Module | ||
| 2021 | Kenworth | W900 | w/BEHR Cooling Module | ||
| 2021 | Peterbilt | 365 | w/BEHR Cooling Module | ||
| 2021 | Peterbilt | 367 | w/BEHR Cooling Module | ||
| 2021 | Peterbilt | 389 | w/BEHR Cooling Module | ||
| 2020 | Kenworth | T660 (Mexico) | w/BEHR Cooling Module | ||
| 2020 | Kenworth | T800 | w/BEHR Cooling Module | ||
| 2020 | Kenworth | W900 | w/BEHR Cooling Module | ||
| 2020 | Peterbilt | 365 | w/BEHR Cooling Module | ||
| 2020 | Peterbilt | 367 | w/BEHR Cooling Module | ||
| 2020 | Peterbilt | 389 | w/BEHR Cooling Module | ||
| 2019 | Kenworth | T660 | w/BEHR Cooling Module | ||
| 2019 | Kenworth | T800 | w/BEHR Cooling Module | ||
| 2019 | Kenworth | W900 | w/BEHR Cooling Module | ||
| 2019 | Peterbilt | 365 | w/BEHR Cooling Module | ||
| 2019 | Peterbilt | 367 | w/BEHR Cooling Module | ||
| 2019 | Peterbilt | 389 | w/BEHR Cooling Module | ||
| 2018 | Peterbilt | 348 | Front | w/BEHR Cooling Module | |
| 2018 | Peterbilt | 365 | Front | w/BEHR Cooling Module | |
| 2018 | Peterbilt | 367 | Front | w/BEHR Cooling Module | |
| 2017 | Kenworth | T660 | Front | w/BEHR Cooling Module | |
| 2017 | Kenworth | T800 | Front | w/BEHR Cooling Module | |
| 2017 | Kenworth | W900 | Front | w/BEHR Cooling Module | |
| 2017 | Peterbilt | 348 | Front | w/BEHR Cooling Module | |
| 2017 | Peterbilt | 365 | Front | w/BEHR Cooling Module | |
| 2017 | Peterbilt | 367 | Front | w/BEHR Cooling Module | |
| 2017 | Peterbilt | 382 | Front | w/BEHR Cooling Module | |
| 2017 | Peterbilt | 389 | Front | w/BEHR Cooling Module | |
| 2016 | Kenworth | T660 | Front | w/BEHR Cooling Module | |
| 2016 | Kenworth | T800 | Front | w/BEHR Cooling Module | |
| 2016 | Kenworth | W900 | Front | w/BEHR Cooling Module | |
| 2016 | Peterbilt | 348 | Front | w/BEHR Cooling Module | |
| 2016 | Peterbilt | 365 | Front | w/BEHR Cooling Module | |
| 2016 | Peterbilt | 367 | Front | w/BEHR Cooling Module | |
| 2016 | Peterbilt | 382 | Front | w/BEHR Cooling Module | |
| 2016 | Peterbilt | 384 | Front | w/BEHR Cooling Module | |
| 2016 | Peterbilt | 386 | Front | w/BEHR Cooling Module | |
| 2016 | Peterbilt | 389 | Front | w/BEHR Cooling Module | |
| 2015 | Kenworth | T600 | Front | w/BEHR Cooling Module | |
| 2015 | Kenworth | T660 | Front | w/BEHR Cooling Module |
Product Specifications
| Cap Included: | Yes |
|---|---|
| Cap Maximum Pressure Rating: | 15 PSI |
| Cap Type: | Spring Loaded Twist |
| Color: | Clear |
| Material: | Plastic |
| Mounting Brackets Included: | Yes |
| Mounting Hardware Included: | No |
| Mounting Hole Quantity: | 2 |
| Package Contents: | 1 Coolant Reservoir; 1 Cap |
| Package Quantity: | 1 |
| Packaging Type: | Box |
| Pressurized: | Yes |
OE Numbers
| DIRECT OE CROSS | |
|---|---|
| N5346001 | PACCAR |