Dorman Front Coolant Reservoir for Jeep Wrangler — 603-773 Non-Pressurized Tank with Cap, OE-Style Fit

The Dorman 603-773 front coolant reservoir with cap is a direct-fit replacement designed to restore the coolant overflow and expansion function on compatible Jeep Wrangler models.

If your Jeep’s plastic coolant tank has cracked, leaked, or lost its cap seal, this Dorman replacement delivers the same mounting points, inlet/outlet locations, and overall shape as the original equipment so you can reinstall a dependable reservoir without modifying hoses or brackets. Constructed from heat- and vibration-resistant materials, the unit is engineered to withstand underhood conditions while providing the same basic function as the factory part.

How does this reservoir match the original part?

Designed to mimic the original reservoir’s fit and connections, the Dorman 603-773 aligns with factory mounting tabs and hose fittings so installation requires minimal adjustment. The included cap completes the assembly so you don't need to reuse an old, potentially degraded cap.

• OEM-style mounting points and hose ports
• Preinstalled cap matching original thread and seal
• Same overall shape for clearance under the hood
• No cutting, trimming, or bracket fabrication required

What materials and construction features help it last under the hood?

Manufactured from durable plastic compounds formulated for automotive use, the reservoir resists common causes of failure like warping from heat and stress cracking from vibration. Dorman applies long-running aftermarket design know-how to ensure the part handles the thermal cycles typical of gasoline engines.

• Heat-tolerant polymer body
• Robust neck and cap seating to maintain a secure seal
• Reinforced mounting areas to resist vibration wear
• Corrosion-resistant fittings and molded hose bosses

Which Jeep models and years is this compatible with?

This Dorman reservoir is specified for several model years of the Jeep Wrangler. Compatibility depends on exact model and trim, so verifying fitment with your vehicle’s trim and VIN is recommended before purchase.

• Jeep Wrangler JK model year listed: 2018
• Jeep Wrangler model years listed: 2012–2019 (select trims)
• Always confirm exact fit using the vehicle garage tool or VIN input
• Compatible with vehicles that share the factory reservoir layout

Is installation difficult for a home mechanic?

Installation is straightforward for most DIYers familiar with basic underhood work: drain a small amount of coolant, disconnect the hoses and electrical connections if present, unbolt the old tank, and swap in the replacement. Because it matches OE fit, reassembly typically uses the same fasteners and hoses.

• Standard hand tools are sufficient for removal and installation
• Minimal coolant loss if performed carefully; have a catch pan ready
• Follow vehicle service guidelines for system bleeding and refill
• Cap included—no separate purchase required

Who is this for: The Dorman 603-773 front coolant reservoir with cap is intended for Jeep owners and independent repair shops seeking a cost-effective, OE-compatible replacement for a cracked, leaking, or aged coolant overflow tank on supported Wrangler model years. It's a practical choice for DIY repairs or fleet maintenance when you need a direct-fit part that restores original routing and mounting without custom work.