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Radiator Leak Sealer

10 Best Radiator Leak Sealer 2025 in the United States

Name: K-Seal ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required
Brand: K-Seal
Price: 12.45 USD
Availability: InStock

From leading brands and best sellers available on the web.

Winner

K-Seal

K-Seal ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

9.7

score

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Bar's Leaks

Bar's Leaks 1186 Liquid Aluminum Stop Leak - 16.9 oz

9.4

score

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Permatex

Permatex 30301 Radiator Repair - Stop Leak, 16 fl oz, Protecting Against Coolant Loss, Stopping Leaks and Seepage from Head Gaskets

9.2

score

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K-Seal

K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

8.9

score

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Liqui Moly

Liqui Moly Radiator Stop Leak | 250 ml | Cooler additive | SKU: 20132

8.6

score

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Bar's Leaks

Bar's Leaks 1109 Block Seal Liquid Copper Intake and Radiator Stop Leak - 18 oz.

8.4

score

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Permatex

Permatex 82099 Spray Sealant, 12 oz.

8.1

score

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Bar's Leaks

Bar's Leaks PLT11 Pelletized HD Radiator Stop Leak - 11 oz.

7.8

score

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Prestone

Prestone AS145 Stop Leak Repair for Radiators, Heater Cores, and Hoses, 11 oz., 1 Pack

7.5

score

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#10

Bar's Leaks

Bar's Leaks HDC Radiator Stop Leak Tablet - 60 Grams, Brown

7.2

score

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How do we rank products for you?

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10 Best Radiator Leak Sealer 2025 in the United States

K-Seal ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

Bar's Leaks 1186 Liquid Aluminum Stop Leak - 16.9 oz

Permatex 30301 Radiator Repair - Stop Leak, 16 fl oz, Protecting Against Coolant Loss, Stopping Leaks and Seepage from Head Gaskets

K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

Liqui Moly Radiator Stop Leak | 250 ml | Cooler additive | SKU: 20132

Bar's Leaks 1109 Block Seal Liquid Copper Intake and Radiator Stop Leak - 18 oz.

Permatex 82099 Spray Sealant, 12 oz.

Bar's Leaks PLT11 Pelletized HD Radiator Stop Leak - 11 oz.

Prestone AS145 Stop Leak Repair for Radiators, Heater Cores, and Hoses, 11 oz., 1 Pack

Bar's Leaks HDC Radiator Stop Leak Tablet - 60 Grams, Brown

FAQ

What is the best radiator leak sealer on the market?

How does a radiator leak sealer work?

Is it safe to use a radiator leak sealer?

Can I use radiator leak sealer for a large leak?

How long does a radiator leak sealer last?

10 Best Radiator Leak Sealer 2025 in the United States

K-Seal ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

Bar's Leaks 1186 Liquid Aluminum Stop Leak - 16.9 oz

Permatex 30301 Radiator Repair - Stop Leak, 16 fl oz, Protecting Against Coolant Loss, Stopping Leaks and Seepage from Head Gaskets

K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

Liqui Moly Radiator Stop Leak | 250 ml | Cooler additive | SKU: 20132

Blue Magic 1116 Liquid Glass Metallic Seal-Up - 22.8 oz.

Bar's Leaks 1196 Radiator Stop Leak - 11 oz. , Grey

BlueDevil Products 00205 Radiator & Block Sealer - 16 Ounce

Bar's Leaks Radiator Stop Leak Tablets, 1.76oz

Solv-Tec Inc. ST5516 16oz. K-Seal TM Heavy Duty Multi-Purpose Permanent Coolant Leak Repair

Bar's Leaks 1109 Block Seal Liquid Copper Intake and Radiator Stop Leak - 18 oz.

Permatex 82099 Spray Sealant, 12 oz.

Bar's Leaks PLT11 Pelletized HD Radiator Stop Leak - 11 oz.

Prestone AS145 Stop Leak Repair for Radiators, Heater Cores, and Hoses, 11 oz., 1 Pack

Bar's Leaks HDC Radiator Stop Leak Tablet - 60 Grams, Brown

Transmission Leak Sealer

Refrigerant Leak Sealer

Radiator Stop Leaks

Radiators

FAQ

What is the best radiator leak sealer on the market?

How does a radiator leak sealer work?

Is it safe to use a radiator leak sealer?

Can I use radiator leak sealer for a large leak?

How long does a radiator leak sealer last?