Dorman 603-869 Engine Coolant Reservoir

Engine Coolant Reservoir for Colorado and Canyon

This Dorman engine coolant reservoir is a standard replacement for select Chevrolet Colorado and GMC Canyon models. Built from plastic with a smooth, uncoated black finish, it is engineered to match the fit and function of the original reservoir while handling underhood heat and engine vibration.

Part number 603-869 is a direct-fit cooling system component for 2015-2022 Chevrolet Colorado and 2015-2022 GMC Canyon applications. It includes a twist cap, is pressurized, and is shaped for OE-style mounting on the vehicle.

Key Features

• Brand: Dorman 603-869
• Engine coolant reservoir / expansion tank replacement
• Plastic construction with smooth, uncoated black surface
• Twist cap included; cap pressure rating: 20
• Pressurized design for cooling system use
• Mounting brackets included for OE-style installation
• Standard replacement grade
• Compatible with 2015-2022 Chevrolet Colorado and 2015-2022 GMC Canyon

Detailed Description

Dorman 603-869 is engineered as a replacement coolant reservoir for the Chevrolet Colorado and GMC Canyon. It is manufactured to match the original part’s fit and function, with mounting points and dimensions intended to align with the factory cooling system layout. The reservoir uses durable plastic construction to withstand heat cycling and vibration in the engine bay.

This part cross-references GM applications such as 23144522 and 84388367 for the same application. For buyers searching for a 2015-2022 Chevrolet Colorado coolant reservoir or a 2015-2022 GMC Canyon coolant reservoir, this part number 603-869 provides a direct replacement option.

What It Helps Address

• Cracked or leaking coolant reservoir housing
• Loss of coolant from a damaged expansion tank
• Broken cap or sealing issues at the reservoir
• Heat-related plastic fatigue in the cooling system
• Fitment problems caused by a worn OE reservoir

Installation Notes and Tips

Verify vehicle year, make, and model before installation. Confirm that the reservoir mounting points, cap style, and pressurized system requirements match the original component. Inspect hoses, clamps, and the cap sealing surface during replacement to help ensure proper cooling system operation. This reservoir is listed with 2 mounting holes and 11 mounting points, so compare the OE layout before installation.

Quality Assurance

Dorman manufactures this replacement reservoir to match original fit and function using materials selected for underhood conditions. It is built as a standard replacement part for Chevrolet Colorado and GMC Canyon cooling system service.