YzusGomumu Coolant Reservoir Tank for Cadillac Chevy GMC Buick — Direct-Fit OE Replacement, Heat-Resistant

YzusGomumu coolant reservoir tank is a direct-fit replacement overflow tank designed to restore proper coolant circulation and maintain engine temperature for select Cadillac, Chevrolet, GMC and Buick models.

This replacement radiator coolant reservoir is engineered as a durable, OE-style tank to replace cracked, leaking, or discolored overflow bottles. It restores a visible coolant level, seals to the cooling system, and helps the system vent and recover coolant during normal operation. The part matches OE numbers 23386455 and 603-861; buyers should verify fitment against their vehicle's engine code and year before ordering.

How does this tank affect everyday vehicle reliability?

Replacing a worn or damaged coolant reservoir prevents coolant loss, reduces air entering the cooling system, and preserves consistent engine operating temperature. A proper overflow tank also keeps the coolant level visible and helps avoid overheating caused by low coolant. Installing a new tank is a simple preventive repair that reduces the chance of more expensive cooling-system damage.

• Direct-fit design for listed models (see compatibility list below)
• Restores visible coolant level and safe venting
• Made to resist temperature and pressure cycles

Will this YzusGomumu part fit my specific vehicle and engine?

This reservoir fits many recent Cadillac, Chevrolet, GMC and Buick vehicles with specific engine sizes and years. Always compare the OE numbers and your vehicle’s current reservoir part number before purchasing to ensure exact fitment. If your vehicle matches one of the listed model-year and engine combinations, this tank is intended as a compatible replacement.

• OE numbers: 23386455 and 603-861 — verify against your part
• Compatible with Cadillac XT4/XT5/XT6, Chevrolet Blazer/Equinox/Malibu, GMC Acadia/Terrain, Buick LaCrosse/Regal/Envision (see full list in features)
• Check engine size and production year for compatibility

What materials and durability features should I expect?

The YzusGomumu reservoir is molded from high-quality, heat-resistant plastic formulated for long-term exposure to coolant and temperature swings. The construction is designed to tolerate pressure variations and repeated thermal cycling without cracking or deforming. You can expect a longer service life compared with brittle, aged OEM bottles.

• Heat-resistant plastic resists warping and stress
• Seals and neck profiles match OEM mating points
• Designed to endure repeated thermal and pressure cycles

How difficult is installation and what should I prepare?

Installation is straightforward for a mechanically minded DIYer and typically requires basic hand tools and coolant handling. Drain the cooling system to below the reservoir level, unclip hoses, remove mounting fasteners, and swap the old tank for the new one. Replace hoses or clamps if damaged and refill with the manufacturer-recommended coolant, then bleed the system per vehicle procedure.

• Basic tools: pliers, screwdrivers, socket set
• Prepare coolant catch pan and replacement coolant
• Inspect hoses, clamps, and cap during install

Who is this for: This YzusGomumu coolant reservoir tank is aimed at owners and technicians working on 2016–2021 Cadillac, Chevrolet, GMC or Buick vehicles listed in the compatibility notes who need a reliable OEM-style replacement. It’s suited to drivers repairing age-related cracks, leaks, or discoloration in the original tank and for service shops seeking a cost-effective, durable aftermarket option. Always confirm OE numbers 23386455 or 603-861 and vehicle-specific fitment before ordering to ensure correct application.

Compatibility highlights (excerpt): 2019-2021 Cadillac XT4 2.0L; 2020-2021 Cadillac XT5 2.0L / 3.6L; 2021 Cadillac XT6 2.0L / 3.6L; 2020-2021 Chevrolet Blazer 2.0L/2.5L/3.6L; 2016-2021 Chevrolet Malibu 1.5L/2.0L; 2018-2021 Chevrolet Equinox 1.5L/2.0L/1.6L; 2017-2021 GMC Acadia 2.0L/2.5L/3.6L; 2018-2021 GMC Terrain 1.5L/2.0L/1.6L; 2017-2019 Buick LaCrosse 3.6L; 2018-2021 Buick Regal/Envision models. Please verify part numbers before installation.