Dorman Front Pressurized Coolant Reservoir for Cadillac/Chevrolet/GMC 2014–2019 — Direct-Fit with Cap Interface

Dorman 603-973 is a front pressurized engine coolant reservoir designed as a direct-fit replacement for select Cadillac, Chevrolet and GMC models, restoring proper coolant containment and cap sealing.

If your factory overflow bottle has cracked, warped, or failed to hold pressure, the Dorman 603-973 offers a durable aftermarket alternative engineered to match OEM fit and function. Molded from materials tested for underhood heat and vibration, this reservoir comes with the correct cap interface and mounting points so installation is straightforward for DIYers and technicians alike. Confirm fit by selecting your exact make, model and trim in the vehicle garage tool before ordering.

How does this reservoir match the original part?

The Dorman 603-973 is manufactured to align with the factory dimensions, mounting bosses, and hose connections so it replaces the original without modification. It’s built to accept the same style pressure cap and sits in the same front-engine location as the OEM unit.

• Direct replacement design—same shape and mounting points as the original
• Compatible cap interface for proper pressure sealing
• Preformed inlet/outlet locations for existing hoses

Will this reservoir withstand underhood heat and vibration?

Yes—Dorman engineers select thermoplastics and reinforcements to resist common causes of coolant tank failure, such as thermal cycling and engine vibration. While no part is immune to extreme conditions, this reservoir is made to endure typical operating environments for the listed vehicles.

• Durable molded construction resists cracking and warping
• Engineered for thermal stability across normal temperature ranges
• Designed to tolerate vibration from everyday driving and towing loads

What vehicles and model years does this part fit?

This reservoir is compatible with a range of late-model Cadillac, Chevrolet and GMC trucks and SUVs—covering many model years from 2014 through 2019. Use the product’s fitment tool to verify match for your specific trim before purchase to avoid returns.

• Cadillac Escalade and Escalade ESV: 2015–2019
• Chevrolet Silverado, Tahoe, Suburban, Cheyenne: select 2014–2019 years
• GMC Sierra, Yukon, Yukon XL: select 2014–2019 years (verify trim)

How easy is installation and what should I prepare?

Installation is typically straightforward for someone comfortable with basic automotive maintenance. You’ll need to drain a small amount of coolant, remove the old reservoir, transfer any sensors or fittings, and reattach hoses and the cap—then refill and bleed the cooling system as required.

• Basic hand tools required—screwdrivers, pliers, socket set
• Plan to capture escaping coolant and top off with proper coolant type
• Inspect hoses and clamps; replace if brittle or corroded

Who is this for? The Dorman 603-973 coolant reservoir is aimed at owners and technicians of compatible Cadillac, Chevrolet and GMC trucks and SUVs who need a reliable, OEM-matching replacement without the premium OEM price. It’s a practical choice for fleet maintenance, DIY repairers, and independent shops seeking durability, correct fitment, and an easier installation process. Always confirm vehicle compatibility with the garage tool and follow manufacturer guidance for coolant type, system pressure checks, and bleeding procedures.