Dorman Non-Pressurized Coolant Reservoir with Cap for Acura TL 2004–2008 / Honda Accord 2003–2007 — Direct-Fit, Heat-Resistant

If your vehicle’s coolant overflow tank is cracked, leaking, or the cap no longer seals, the Dorman 603-227 non-pressurized coolant reservoir offers a direct-fit replacement for select Acura TL and Honda Accord model years. Built from materials chosen for durability around the engine bay, this reservoir is made to replicate the fit and mounting points of the factory part so installation is straightforward for DIYers and shops alike.

Will this reservoir fit my Acura TL or Honda Accord?

The Dorman 603-227 is designed specifically for certain model years of the Acura TL (2004–2008) and Honda Accord (2003–2007). Before ordering, confirm your exact year and trim using the vehicle fitment tool to ensure correct alignment of mounting bosses and hose connections.

• Compatible Acura TL model years: 2004, 2005, 2006, 2007, 2008
• Compatible Honda Accord model years: 2003, 2004, 2005, 2006, 2007
• Use the store’s garage/fitment checker to verify trim-specific fit

How does installation compare to the original part?

This reservoir is made to match the original in shape, mounting points, and hose locations, which keeps installation simple and reduces the need for modifications. Most buyers will find the swap requires standard hand tools and basic mechanical knowledge.

• Direct replacement design mirrors factory tank geometry
• Pre-formed mounting points for bolt- or clip-style attachment
• Included cap matches factory sealing style for non-pressurized systems

What materials and durability features does it offer?

Manufactured from automotive-grade plastics selected for resistance to heat and vibration, the reservoir is built to endure repeated thermal cycles and road conditions. The construction aims to prevent premature cracking, swelling, or leaks common in older or degraded tanks.

• Heat-resistant polymer body resists underhood temperatures
• Vibration-tolerant design for long-term service life
• Factory-style cap included to maintain proper overflow behavior

What should I check before and after installing this part?

Before installing, inspect hose ends and clamps for wear and replace if necessary to ensure a leak-free connection. After installation, fill the cooling system to the correct level and run the engine to check for leaks and proper coolant circulation.

• Verify hose diameter and clamp condition at the connection points
• Bleed air from the cooling system per manufacturer instructions
• Check for leaks after reaching normal operating temperature

Who is this for: The Dorman 603-227 reservoir is intended for vehicle owners and mechanics restoring coolant system reliability on compatible Acura TL and Honda Accord models. It’s a practical option for anyone replacing a cracked or leaking tank who wants a direct-fit, durable component that aligns with factory mounting and sealing methods without custom fabrication.