Dorman Front Coolant Reservoir with Cap for Jeep Wrangler — Direct-Fit Replacement, Heat-Resistant Polymer

This Dorman 603-773 front coolant reservoir with cap is a direct-fit replacement engineered to restore proper coolant overflow function on compatible Jeep Wrangler models.

If your vehicle’s plastic coolant tank is cracked, leaking, or has a malfunctioning cap seal, replacing it with a properly engineered unit helps maintain coolant level control and reduces the risk of underhood coolant loss. Dorman designs this reservoir to match the original part’s shape and mounting points so you can install it without modifying brackets or hoses. Built from heat-tolerant materials, the assembly includes the cap and is intended for specified Jeep Wrangler model years — verify your trim in the garage tool before purchase.

How does this reservoir match the original fit and function?

The reservoir is molded to align with OE mounting tabs, hose connections, and filling neck location so the swap is straightforward. Dorman engineers the part to replicate the original dimensions and connector positions to avoid clearance or routing issues under the hood.

• Molded mounting bosses that match factory bracket points
• Pre-located hose inlet and outlet ports for direct hose connection
• Included cap sized for the original filling neck
• Shape and volume designed to mirror the OEM reservoir

What materials and construction provide durability?

This reservoir is produced from automotive-grade plastics formulated to resist heat cycling and engine vibration. The construction aims to reduce stress cracking and prolong service life compared with brittle or aged tanks.

• Heat-resistant polymer that tolerates underhood temperatures
• Reinforced neck and mounting areas to withstand tightening and vibration
• Corrosion-free material—no metal to rust
• Quality control to maintain consistent wall thickness and seals

How easy is the installation process for a DIYer?

Installation is typically straightforward: drain or capture excess coolant, disconnect hoses and mounting fasteners, swap tanks, reconnect hoses, and top up coolant. Because the reservoir is built to mirror the original, most installations require only common hand tools and basic mechanical skill.

• Direct-fit design reduces need for trimming or adapters
• Standard hose clamps and fasteners are used for reassembly
• Refill and bleed procedures follow the vehicle maker’s coolant guidelines
• Estimated time: about 30–90 minutes depending on access

Which vehicles is this reservoir compatible with?

This Dorman reservoir fits specific Jeep Wrangler model years; compatibility depends on trim and original equipment. Always confirm fitment by entering your exact make, model, and trim into the garage tool before ordering to ensure it matches your vehicle’s factory configuration.

• Compatible with Jeep Wrangler JK and later model listings per Dorman fitment
• Designed to replace the factory front coolant overflow tank and cap assembly
• Fits model years listed by the manufacturer—verify trim-specific details
• Not universal; check fitment before purchase to avoid returns

Who is this for: This replacement is intended for Jeep owners and independent technicians who need a reliable, cost-effective coolant overflow reservoir that installs like the original part. It’s suitable for routine maintenance or emergency replacement when the stock tank shows cracks, leaks, or degraded cap sealing. If you value straightforward installation, OE-like fit, and a plastic reservoir built to withstand engine bay conditions, this Dorman assembly is a practical option. Remember to confirm your vehicle year and trim with the garage tool to ensure exact compatibility.