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Bar's Leaks Block Seal Head Gasket Sealant Head Gasket Repair 20 oz

Made in America

Support American manufacturers + independent hardware retailers in one purchase.

Seals leaking head gaskets from inside the cooling system, stopping coolant loss and overheating without a teardown.
Bar'S Leaks MPN 1100 In Stock & Ready to Ship
$13.99
Free shipping on orders over $75
Ships within 24 hours · most orders arrive in about 2 business days

About Product Overview

A cracked head gasket or leaking cooling system doesn't always mean a trip to the mechanic. Bar's Leaks Head Gasket Repair pours straight into your radiator to seal small leaks in the head gasket, block, and cooling system from the inside, buying you time and money before committing to a full repair.

Part of the Block Seal line, this 20 oz formula is a straightforward fix for coolant loss, overheating, or white exhaust smoke tied to a leaking gasket. Made in the USA and sized for a single treatment.

  • Brand: Bar's Leaks
  • Sub-brand: Block Seal Head Gasket Sealant
  • Container size: 20 oz
  • Product type: Head gasket repair / cooling system chemical
  • Made in USA

The Details Specifications

Brand Bar'S Leaks
Model / MPN 1100
UPC 046087011003
Weight 1 lbs
Country of Origin USA
Safety Data Sheet (SDS) Manufacturer documentation · opens in new tab
Price check

Go ahead. Check.

You're going to price-check us against Amazon, Home Depot, and Lowe's. Everybody does. Good — open all three tabs. We'll wait. Then look hard at what you're actually being handed over there.

On Amazon, start with these four questions before you click buy.

01

Who's actually selling it

The brand name is on the listing. A different company is in the seller field. Those aren't the same thing, and the second one is who you're buying from.

02

Whether the warranty survives

Most manufacturers only honor a warranty when the unit came through an authorized dealer. We're authorized for Bar'S Leaks. A third-party marketplace seller usually isn't.

03

Where the box came from

Gray-market stock, returns repackaged as new, and outright fakes move through marketplaces constantly. It all looks identical in the photo. It stops looking identical when it fails.

04

Who you call when it breaks

Ours is a phone number with a person behind it who has held this product. M–F, 6 AM – 5 PM Pacific. (866) 469-8556

The big boxes don't care if your hardware store survives.

Amazon, Home Depot, and Lowe's are built to pull every hardware dollar out of your town. When the local shop can't keep the lights on, the counter where somebody actually knew which part you needed goes with it. We're built the other way: real brands so you're never stuck on a marketplace, and a straight answer to buy it down the street when that's the better call. Support independent hardware — it doesn't restock itself.

Why we tell you to shop local
Authorized dealer · Bar'S Leaks

Or skip the tabs entirely and buy it down the street. Find a store near you →

Shop Local · Support Independent

Every order helps keep your local hardware store on the corner.

Why we built NHG
You might find it for less locally. Independent retailers often offer competitive pricing — some products are even cheaper in-store than online.
Real expert advice — not search results. Independent hardware staff know their inventory and the local conditions you're working in.
Keep the neighborhood working. Every dollar spent at an independent retailer returns roughly 3x more to your local economy than at a national chain.

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