Dorman Pressurized Coolant Reservoir for Buick/Chevrolet — 603-383 with Cap, OE-fit Durable Heat-Resistant Tank

This Dorman 603-383 pressurized coolant reservoir with cap is a direct-fit replacement engineered to restore proper coolant expansion and recovery on compatible Buick and Chevrolet vehicles.

When a cracked or leaking coolant reservoir threatens engine cooling performance, replacing it with a properly matched unit restores system integrity without aftermarket guesswork. The Dorman 603-383 is manufactured to mirror the original reservoir’s shape, mounting points and inlet/outlet locations so it installs cleanly and behaves like the factory part. It includes the pressurized cap and is built from materials intended to resist engine-bay heat and vibration.

How does this reservoir match the original part?

Rather than a universal or generic tank, this Dorman reservoir is made to align with the original equipment’s dimensions and connection points. That reduces trimming or modification during installation and helps the hoses and sensors seat correctly.

• OEM-style mounting bosses and bracket locations for straightforward fitment
• Correct inlet, outlet and overflow port placement to match factory hoses
• Integrated pressurized cap sized to original specifications

Will it withstand underhood heat and vibration?

Yes — Dorman constructs this reservoir from durable plastics chosen for thermal and mechanical resilience. The material selection and wall thickness aim to resist the expansion, flexing and thermal cycles typical in passenger-car engine compartments.

• Heat-resistant molded body designed for long-term service
• Reinforced areas at mounting points to resist vibration wear
• Pressurized cap engineered to maintain correct system pressure

Which vehicles is the 603-383 compatible with?

This replacement tank is intended for a range of Buick and Chevrolet models across specified years. Always confirm fitment for your exact vehicle trim using the store’s garage or fitment tool before purchasing to ensure compatibility.

• Buick Cascada: 2016–2019
• Buick Verano: 2012–2017
• Chevrolet Cruze: 2010–2016 (includes Cruze Limited 2016)
• Chevrolet Orlando: 2012–2014

What should I expect during installation?

The Dorman 603-383 is engineered for a plug-and-play replacement, so most technicians and experienced DIYers will find the changeover straightforward. Typical steps include draining coolant to the appropriate level, disconnecting hoses and electrical connectors, unbolting the old tank and transferring any sensors or fittings if necessary.

• Minimal trimming or adapter parts required when fitment is confirmed
• Includes the pressurized cap to simplify the swap
• Re-use or replace quick-clamps and hoses if they show wear

Who is this for: Owners, independent mechanics and fleet technicians servicing compatible Buick and Chevrolet models who need a robust, direct-replacement coolant reservoir. It suits anyone seeking a factory-like fit and finish without modifying mounting points or hose routing. Before ordering, verify your vehicle year, make and trim in the fitment tool to confirm this Dorman reservoir matches your specific application.