--- product_id: 50154348 title: "Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red" price: "€ 23.70" currency: EUR in_stock: true reviews_count: 13 url: https://www.desertcart.pt/products/50154348-pro-line-radiator-stop-leak-k-250-ml-cooler-additive store_origin: PT region: Portugal --- # Treats up to 40L coolant Works in 10 minutes Seals micro leaks fast Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red **Price:** € 23.70 **Availability:** βœ… In Stock ## Summary > πŸš€ Stop leaks before they stop you – the pro’s choice for radiator peace of mind! ## Quick Answers - **What is this?** Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red - **How much does it cost?** € 23.70 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.pt](https://www.desertcart.pt/products/50154348-pro-line-radiator-stop-leak-k-250-ml-cooler-additive) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Trusted Quality:** From Liqui Moly, a top-rated brand with 4.5-star reviews and proven results - β€’ **Leak-Proof Confidence:** Seals tiny cracks & porous points before they become costly headaches - β€’ **Long-Lasting Protection:** Keeps your cooling system sealed for months, saving you time and money - β€’ **Universal Compatibility:** Perfect for cars, commercial vehicles, and buses with water-cooled engines - β€’ **Quick & Easy Application:** Just shake, pour at operating temp, and run engine for 10 minutesβ€”done! ## Overview LIQUI MOLY Pro-Line Radiator Stop Leak K is a powerful 250 ml additive designed to seal small leaks in vehicle cooling systems quickly and effectively. Suitable for passenger cars, commercial vehicles, and buses, it treats up to 40 liters of coolant and works within 10 minutes of application. Trusted by thousands with a 4.5-star rating, it prevents coolant loss from micro cracks and porous soldering points, ensuring your engine stays cool and leak-free. ## Description From the manufacturer Review: Works as it should - I've used this 3 times now and it's worked every time. Slowly losing coolant and this stopped it dead without discolouring the coolant and causing any blockages. Recommended. Review: It worked for me! - Used on Hyundai i40 1.7 cdti that had a very irritating slow leak from somewhere not obvious. I have no intention to plough money into this car.. it's a mobile tip! First time using anything like this as it goes against my inside engineer.... But to be fair, it's been a few months now since adding it and the coolant leak appears to be sealed! ## Features - Contains reaction mass of 5-chloro-2-methyl-2H-isothiazol-3-one and 2-methyl-2Hisothiazol-3-one (3:1). May produce an allergic reaction. - Safety data sheet available on request. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B004FPUUSS | | Best Sellers Rank | 6,780 in Automotive ( See Top 100 in Automotive ) 88 in Fillers, Adhesives & Sealants | | Brand | Liqui Moly | | Customer Reviews | 4.5 4.5 out of 5 stars (2,878) | | Date First Available | 28 Aug. 2012 | | Item Weight | 275 g | | Item model number | 5178 | | Manufacturer | Liqui Moly | | Manufacturer part number | 5178 | | Model | Pro-Line Radiator Sealer K | | Product Dimensions | 66.09 x 23.6 x 13.41 cm; 275 g | | Viscosity | 2T | ## Images ![Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red - Image 1](https://m.media-amazon.com/images/I/51AL1Pm7wmL.jpg) ![Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red - Image 2](https://m.media-amazon.com/images/I/6141COiHkAL.jpg) ![Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red - Image 3](https://m.media-amazon.com/images/I/61EBu-X5tgL.jpg) ![Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red - Image 4](https://m.media-amazon.com/images/I/716mnETyH-L.jpg) ![Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red - Image 5](https://m.media-amazon.com/images/I/7179+JqsfML.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works as it should *by A***6 on 13 May 2026* I've used this 3 times now and it's worked every time. Slowly losing coolant and this stopped it dead without discolouring the coolant and causing any blockages. Recommended. ### ⭐⭐⭐⭐⭐ It worked for me! *by N***X on 19 November 2025* Used on Hyundai i40 1.7 cdti that had a very irritating slow leak from somewhere not obvious. I have no intention to plough money into this car.. it's a mobile tip! First time using anything like this as it goes against my inside engineer.... But to be fair, it's been a few months now since adding it and the coolant leak appears to be sealed! ### ⭐⭐⭐⭐ Great for small discrepancies in your cooling system *by G***D on 21 April 2026* Worked for a while but ended up replacing thermostat. ## Frequently Bought Together - LIQUI MOLY Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178 - JOVS Jovs Antifreeze Coolant 5 Litre Long Life Red Ready Mixed Engine Coolant Ready to Use - Wynn's Car Radiator Stop Leak Sealant Antifreeze Coolant Repair Additive 325ml --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.pt/products/50154348-pro-line-radiator-stop-leak-k-250-ml-cooler-additive](https://www.desertcart.pt/products/50154348-pro-line-radiator-stop-leak-k-250-ml-cooler-additive) --- *Product available on Desertcart Portugal* *Store origin: PT* *Last updated: 2026-06-14*