YEHERIT Coolant Expansion Reservoir 603-973 with Cap — Direct-Fit PA Plastic Replacement for GM Trucks & SUVs

The YEHERIT 603-973 coolant expansion reservoir tank with cap is a direct-fit replacement reservoir designed to restore proper coolant overflow control and pressure cycling for compatible GM trucks and SUVs.

If your vehicle is showing low-coolant warnings, visible leaks near the coolant neck, or inconsistent cabin heating, a worn or cracked expansion tank could be the cause. This replacement tank is molded from heat-resistant PA plastic, uses OE-equivalent mounting points and inlet/outlet placements, and includes a matching cap to maintain system pressure. It is engineered to match factory dimensions and fluid flow behavior so you can swap it in without custom modifications.

Which vehicles does this reservoir fit and how precise is the fit?

This YEHERIT reservoir fits a range of GM full-size trucks and SUVs from model years 2014–2020, covering specific engine sizes and variants. It corresponds to several OE numbers for cross-reference, making part identification straightforward.

• Cadillac Escalade / Escalade ESV 2015–2020 — 6.2L
• Chevrolet Silverado 1500 2014–2019 — 4.3L & 5.3L; Silverado 1500 LD 2019 — 5.3L
• Chevrolet Suburban 2015–2020 — 5.3L, 6.0L, 6.2L; Suburban 3500 HD 2016–2019 — 6.0L
• Chevrolet Tahoe 2015–2020 — 5.3L & 6.2L
• GMC Sierra 1500 2015–2019 — 4.3L, 5.3L, 6.2L; Sierra 1500 Limited 2019 — 5.3L
• GMC Yukon / Yukon XL 2015–2020 (model years vary) — 5.3L & 6.2L
• Replacement OE numbers: 603-973, 22856231, 671-00359, 603973, 3014134, 67100359

How does this tank affect cooling-system performance?

The expansion tank manages surplus coolant when the engine warms, holding fluid under pressure and returning it to the radiator as temperatures fall. Using a correct, undamaged tank helps maintain stable system pressures and prevents air pockets, contributing to consistent temperature control.

• Holds expanded coolant to avoid overflow and fluid loss
• Supports pressure equalization so coolant flows back to the radiator
• Reduces risk of air intrusion that can cause hot spots or heater-core issues
• Works with the cap to maintain designed operating pressures

What materials and durability features does the YEHERIT unit offer?

Constructed from reinforced PA-grade plastic, the tank resists high under-hood temperatures and vibration. The material choice and molded mounting bosses are intended to endure the thermal cycles common in heavy-duty vehicle use.

• PA plastic formulation resists heat and chemical exposure
• Precision-molded connections match factory hose and cap locations
• Engineered to withstand vibration and thermal expansion cycles
• Includes a compatible pressure cap for correct sealing

Is installation and after-sales support available if I need help?

YEHERIT provides a one-year unlimited-mileage guarantee on this expansion tank and offers customer support for fitment or installation questions. Basic replacement is a moderate DIY job for mechanically inclined owners, but professional installation is recommended if you're unsure.

• One-year unlimited-mileage warranty from YEHERIT
• Customer support response within 48 hours for questions
• Direct-fit design reduces need for trimming or adapters
• Consult vehicle service manual for safe coolant draining and refilling

Who is this for: This YEHERIT expansion reservoir is aimed at owners or mechanics of compatible Chevrolet, GMC, and Cadillac trucks and SUVs who need a reliable replacement that matches OEM form and function. It's suitable for drivers noticing coolant loss, overheating indicators, or visible tank damage, and for anyone performing preventative cooling-system maintenance who wants a durable, OE-referenced component with warranty-backed support.