X4XZ Front Engine Coolant Reservoir for Ford 603-382 — Translucent Expansion Tank with Surge Cap

The X4XZ 603-382 front engine coolant reservoir (radiator expansion tank) is a direct-fit replacement reservoir and cap assembly engineered to restore proper coolant overflow and recovery on compatible Ford models.

This replacement coolant expansion tank and surge cap are designed for Ford applications where the original reservoir is cracked, leaking, discolored, or otherwise compromised. Molded from heat-resistant translucent plastic, the X4XZ 603-382 lets you monitor fluid level at a glance and restores the closed-loop overflow behavior that prevents low coolant, air ingression, and inconsistent engine cooling. It is supplied with the surge cap and matches the OE reference numbers shown below—but professional installation is recommended.

Which Ford vehicles use the 603-382 reservoir?

This reservoir fits multiple Ford models with the listed engine sizes and model years. Always verify compatibility by checking the OE part numbers on your existing tank before ordering.

• Ford Focus 2012–2018 (1.0L / 2.0L / Battery EV)
• Ford Escape 2013–2016 (1.6L)
• Ford C-Max 2013–2018 (2.0L)
• Ford Transit Connect 2014–2016 (1.6L)

How does this replacement reservoir restore cooling system function?

The expansion tank collects excess coolant as the engine heats and returns it to the radiator as the system cools, maintaining the correct fluid volume and reducing air pockets in the cooling loop. A damaged or leaking reservoir can lead to visible coolant loss and potential overheating symptoms if left unaddressed.

• Restores overflow and recovery cycle between radiator and tank.
• Prevents coolant loss that leads to low-level warnings and engine heat.
• Translucent construction makes level checks quick and accurate.

What are the key specifications and part numbers to check?

Confirm compatibility by matching the OE or replacement numbers on your original part; the X4XZ unit cross-references several common Ford OE numbers. The package includes one tank plus one surge cap; instructions are not included so installation by a technician or experienced DIYer is advised.

• Main reference: 603-382 (X4XZ part)
• Replaces OE#: 8V618K218AE, CV6Z8A080A, CV6Z-8A080-A, 603382, BE8Z8100A
• Package: 1 coolant reservoir and 1 surge cap; no printed instructions

Is this reservoir durable and what materials are used?

The X4XZ expansion tank is manufactured from heat-and-vibration-resistant plastic suitable for under-hood conditions. It’s a non-OEM direct replacement that balances cost and fit while providing visible coolant monitoring through a translucent finish.

• High-quality plastic resists heat, vibration, and common underhood stresses.
• Translucent body enables quick visual inspections without opening the system.
• Supplied surge cap designed to reseal the cooling circuit after replacement.

Who is this for: The X4XZ 603-382 radiator expansion tank is aimed at Ford owners, mechanics, and DIY enthusiasts who need a reliable, affordable direct replacement for a leaking or damaged coolant reservoir on compatible Focus, Escape, C-Max, and Transit Connect vehicles. If your vehicle’s coolant tank shows cracks, coolant loss, or discoloration—or if you’re prepping a vehicle for resale—this part restores the overflow/recovery function. Remember to confirm OE numbers and consult a trained technician if you aren’t comfortable performing the installation yourself. X4XZ provides one-year product support and 24-hour customer service for fitment or quality questions.