ACDelco Radiator Leak Sealant

ACDelco Radiator Leak Sealant: GM-Engineering Meets Cooling System Protection

A slow coolant leak can quickly escalate from a minor nuisance into a serious engine problem. ACDelco brings the same General Motors-backed engineering that goes into original equipment parts directly to the world of radiator leak sealants — offering a targeted, trusted solution for drivers dealing with minor cooling system leaks before they become costly repairs.

What Makes ACDelco's Radiator Leak Sealant Stand Out

GM Original Equipment pedigree is at the core of what separates ACDelco's approach to cooling system repair from generic aftermarket alternatives. ACDelco is the premier supplier of GM Original Equipment automotive replacement parts, and that same design and testing philosophy carries over into its chemical product lines. ACDelco's cooling system leak sealant products are designed, engineered, and tested to rigorous standards and are backed by General Motors — a distinction that matters when you're trusting a product to protect your engine's cooling circuit.

ACDelco's flagship entry in this category is its Cooling System Sealing Tabs (Part No. 10-108 / GM Part No. 12378255). These small, 4-gram tablets are purpose-built for the cooling system environment. Key features of this product include:

• Dissolves in water or antifreeze — the tablet format integrates directly into the coolant without needing to drain the system first
• Lubricates components and seals leaks — providing dual-action protection within the radiator circuit
• Targets minor leaks from casting porosity — particularly well-suited for the small, hard-to-find seepage points common in aging engines
• Compatible with cars and pickup trucks — a versatile solution across a wide range of GM and non-GM vehicles

Understanding the Role of Radiator Leak Sealant

Radiator leak sealants like ACDelco's Cooling System Sealing Tabs are best understood as a smart first-response tool for minor cooling system leaks — not a substitute for mechanical repair on significant damage. They work by forming a seal at the site of small leaks, slowing or stopping coolant loss caused by hairline cracks, porous castings, or minor gasket weepage. ACDelco's GM-heritage formulation is specifically designed to tackle the coolant leaks commonly found in older engines, and the sealing effect may develop gradually over a period of driving miles.

As with any stop-leak product, it's always wise to have a technician assess the severity of the leak first. ACDelco itself recommends consulting a technician to determine whether the leak is too large for a sealant solution and to ensure proper application. For anything beyond minor seepage, a full cooling system inspection — including the radiator, heater core, hoses, and water pump — is the right path forward.

Why Choose ACDelco for Cooling System Chemicals

ACDelco offers nearly 90,000 auto parts across 37 product lines, and its chemicals and fluids carry the same commitment to quality as its hard parts. Whether you're a DIYer looking for a quick fix for a minor coolant leak or a shop tech reaching for a proven GM-approved product, ACDelco's radiator leak sealant delivers the confidence of OE-level engineering in an easy-to-use tablet format. Most ACDelco OE and Professional line products are also backed by a 24-Month/Unlimited Mile Warranty, underscoring the brand's commitment to standing behind what it sells.