Dorman Pressurized Coolant Reservoir with Cap for Dodge Durango & Jeep Grand Cherokee 2016–2021 — Direct-Fit, Heat-Resistant

The Dorman 603-002 is a direct-fit pressurized engine coolant reservoir with cap designed to replace the factory overflow tank on select 2016–2021 Dodge Durango and Jeep Grand Cherokee models.

This replacement coolant reservoir is engineered to match the original equipment's dimensions and performance while resisting underhood heat and vibration. Manufactured from durable materials and supplied with a compatible pressurized cap, it restores proper fluid containment and cooling system pressure behavior. Before ordering, confirm compatibility by entering your vehicle's trim and year in the garage tool to ensure a precise fit.

How does this reservoir restore proper cooling system operation?

The reservoir captures overflow coolant during warm operation and returns it to the system as temperatures fall, helping maintain correct fluid levels and pressure. Because it matches the original fitment and cap specifications, it integrates with existing hoses and mounting points without modification.

• Direct replacement design that aligns with factory mounting locations
• Pressurized cap included to maintain proper cooling system pressure
• Engineered to mate with factory hoses for straightforward installation

What materials and construction features make it reliable under the hood?

This reservoir is molded from heat- and vibration-resistant plastics formulated for automotive underhood environments. The material selection and construction processes aim to minimize stress cracking, deformation, and premature failure compared with generic aftermarket tanks.

• Durable polymer body engineered for sustained heat exposure
• Reinforced mounting points to handle engine vibration
• Factory-style cap sealing surfaces to reduce leaks

How easy is the installation for a DIYer or technician?

Installation is intended to be straightforward because the reservoir is built to OE dimensions and connections. A basic set of tools and moderate mechanical aptitude are usually all that’s required to swap the old tank for this direct-fit unit.

• No modifications needed—uses factory bolt locations and hose fittings
• Comes with a compatible pressurized cap, eliminating a separate purchase
• Remove old tank, transfer hoses if applicable, and secure new reservoir in place

Which vehicles does this part fit and how do I confirm compatibility?

This Dorman reservoir is compatible with specific Dodge Durango and Jeep Grand Cherokee model years listed by the manufacturer. To avoid ordering the wrong part, enter your vehicle’s exact year, make, model, and trim into the garage tool prior to purchase.

• Dodge Durango: model years 2016, 2017, 2018, 2019, 2020, 2021
• Jeep Grand Cherokee: model years 2016, 2017, 2018, 2019, 2020, 2021
• Use the garage tool to verify trim-specific fitment before buying

Who is this for? If you own a compatible Dodge Durango or Jeep Grand Cherokee experiencing coolant loss, visible tank cracks, cap failure, or coolant system pressure issues, this Dorman 603-002 reservoir offers a like-for-like replacement engineered for easy installation. It’s aimed at DIY enthusiasts who want an OE-fit spare part and professional technicians who need a reliable aftermarket option backed by Dorman’s long aftermarket experience. Always confirm fitment through your vehicle details and follow proper cooling-system bleeding procedures after installation to ensure correct operation.