If a leak is trying to ruin your day, we’re the proven, American‑made way to repair it yourself – quickly, simply, and with results built to last since 1947. That’s not just talk – it’s literally 75+ years, more than 400 million leaks sealed, and a mission focused on getting drivers back to life, not stuck with a sidelined car.

Why trust us

We’ve been in the leak‑repair business since 1947, starting with a single radiator formula and growing into America’s most‑trusted stop‑leak brand because results – repeatable, real‑world results – are what matter.

Over the decades our products have sealed more than 400 million leaks, saving consumers billions in avoided repairs and missed time, which is exactly the kind of proof that counts when a vehicle is sidelined. From cooling systems to engines, transmissions, power steering, and more, our solutions are built for daily drivers, weekend toys, and hard‑working equipment – and they’re available through leading retailers nationwide, online and in-store.

Built in the USA

We design, formulate, manufacture, and distribute every single product in the USA, because quality control isn’t a slogan to us – it’s how reliability is engineered. Our home base in Michigan is where the magic happens, and that’s how we keep performance consistent bottle after bottle. Being ISO 9001 certified and proudly American‑made aren’t just talking points; they’re our operating system for doing the job right the first time.

Real‑world proof

Nothing speaks louder than drivers getting back on the road, like the owner who used our Head Gasket Fix (p/n 1111) and reported a full year of drivable life added to a car that would’ve otherwise been parked by a repair quote he couldn’t justify.

Or the DIYer who installed our Radiator Stop Leak Tablets (p/n 1177) into a tired Subaru, watched temps stabilize, and kept coolant topped for the miles that mattered – all for pocket change and minutes of effort. Stories like these are why our formulas have become a go‑to when urgency meets budget, and why the stop‑leak aisle keeps a spot with our name on it. We dominate the category for a reason.

Innovation, not gimmicks

We don’t chase trends; we build tools that solve real problems, like when we expanded beyond cooling system fixes in 1996 to tackle engine, transmission, and power steering repairs with targeted chemistry that actually addresses leak causes. In 2004 we shook up the category with Head Gasket Sealant (p/n 1100), followed by Liquid Copper Block Seal (p/n 1109) in 2008 and Head Gasket Repair (p/n HG-1), our strongest professional‑grade head gasket sealant in 2010 – each designed to be ruthlessly effective and practical. That runway of innovation is why our brand’s still standing tall while fads come and go.

Because functional & proven beats flashy & cheap when the dashboard light comes on.

Easy and fast

Our mission is simple: if someone can open the hood and a bottle, a fix should be within reach – turning everyday drivers into three‑minute mechanics who can get rolling without wrecking a week’s schedule. Clear instructions are right on the label, and the deeper cuts – videos, FAQs, data sheets – live on our site so the path from problem to solution is obvious.

But what if you do have questions about your particular situation? Not a problem. Our Michigan‑based Customer Support staff (real humans, not endless phone menus) pick up the phone and help match the right formula to the job, because support has always been part of our products.

Grab‑and‑go availability

When a vehicle is leaking and threatening downtime, the solution should be close at hand, which is why our products are stocked through leading retailers nationwide for quick pickup or online orders.

Our retail partners will highlight exactly what makes our line different – professional‑grade formulations, U.S. manufacturing, and a single‑minded focus on fast, effective leak repair – so confidence stays high from shelf to checkout. The point is effectiveness without compromise, from aisle to engine bay.

Bottom line

If a leak is trying to hijack your day, we’re the antidote: 75+ years of proof, 400 million seals, and American‑made formulas that punch way above their weight in minutes, not days.

That’s the message behind our promise – stop leaks, not life – and it’s why we’ve been leading the field for over three quarters of a century.