Dorman Front Pressurized Coolant Reservoir with Cap for Cadillac/Chevrolet/GMC 2005–2019 — Direct-Replacement, Durable Fit

The Dorman 603-054 is a direct-replacement pressurized engine coolant reservoir with cap engineered to match original fit and restore the cooling system on compatible Cadillac, Chevrolet, and GMC models.

This replacement coolant reservoir is built to resist underhood heat and vibration while delivering the same shape, mounting points, and cap interface as the factory component. It’s molded from durable materials and designed for straightforward installation so you can return your truck or SUV to reliable coolant containment without extensive modification. Before ordering, use the vehicle lookup or garage tool to confirm exact fitment for your model and year.

Will this reservoir fit my exact vehicle and year?

Fitment is specific to model and production years; Dorman supplies this reservoir for many Cadillac Escalade, Chevrolet Avalanche, Silverado, Suburban, Tahoe, and GMC Sierra and Yukon models listed by year. Check the Confirmed Fit indicator on the product page and enter your vehicle details in the garage tool for verification.

• Compatible with many 2005–2019 Chevy and GMC heavy-duty and light-duty models.
• Includes Cadillac Escalade and Escalade EXT model years noted in the compatibility list.
• If an “i” appears in a blue circle, hover to view any fitment notes before purchasing.
• Always verify trim and engine options to ensure exact match.

How does this Dorman reservoir compare to the original part?

This Dorman reservoir is made to replicate the OEM’s mounting, hose connections, and cap engagement so it installs like the factory unit. Materials and manufacturing tolerances are chosen to withstand engine bay heat and vibration while offering long-term serviceability.

• Direct-replacement design matches factory dimensions and mounting points.
• Pressurized reservoir and cap interface engineered for the correct system pressure.
• Durable plastic resin resists thermal stress and flex under load.
• Backed by Dorman’s aftermarket engineering experience and testing protocols.

What should I expect during installation and maintenance?

Installation is typically straightforward for anyone familiar with basic engine-bay work: drain coolant as needed, remove old reservoir and hoses, fit the new tank, reconnect hoses and sensors, then refill and bleed the cooling system. Follow vehicle-specific service procedures for coolant replacement and air removal.

• Requires basic hand tools and safe coolant handling practices.
• Ensure hose clamps and sensor connectors seat properly to avoid leaks.
• Refill with the manufacturer-specified coolant and complete air-bleeding steps.
• Inspect surrounding components—hoses, clamps, and overflow lines—while replacing the tank.

How durable is the Dorman 603-054 in daily use?

Engineered for the underhood environment, this reservoir uses materials and construction meant to resist cracking and deformation from heat and vibration. While it mirrors OEM fit and function, routine checks for leaks and cap condition help ensure long service life.

• Constructed from heat-resistant plastics sized for engine bay conditions.
• Cap interface designed for correct sealing under system pressure.
• Regular inspection of hoses and clamps reduces risk of failure.
• Designed for straightforward future service or replacement if needed.

Who is this for: The Dorman 603-054 is intended for owners and technicians who need a reliable, direct-fit replacement coolant reservoir for select Cadillac, Chevrolet, and GMC trucks and SUVs listed in the compatibility table. It’s suited to DIY mechanics, independent shops, and fleet maintenance teams seeking an OEM-like fit and straightforward installation—just confirm your vehicle year and trim with the garage tool before purchasing.