--- product_id: 8435813 title: "K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required" brand: "k-seal" price: "€ 43.72" currency: EUR in_stock: true category: "K Seal" url: https://www.desertcart.hr/products/8435813-k-seal-st5516-heavy-duty-multi-purpose-one-step-coolant store_origin: HR region: Croatia --- # Heavy-duty, industrial strength Seals leaks in minutes One-step, no flushing needed K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required **Brand:** k-seal **Price:** € 43.72 **Availability:** ✅ In Stock ## Summary > 🚀 Seal it fast, drive with confidence—no leaks, no limits! ## Quick Answers - **What is this?** K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required by k-seal - **How much does it cost?** € 43.72 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/8435813-k-seal-st5516-heavy-duty-multi-purpose-one-step-coolant) ## Best For - k-seal enthusiasts ## Why This Product - Trusted k-seal brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Rapid Leak Repair:** Fix radiator, head gasket & more in minutes with a single pour - • **Heavy-Duty Strength:** Engineered for commercial, agricultural & large engines - • **Smart Seal Technology:** Automatically targets and seals holes & cracks without harming cooling efficiency - • **Effortless Application:** Pour-and-go formula saves time and keeps your engine running smoothly - • **Universal Compatibility:** Works seamlessly with all antifreeze types—no flushing required ## Overview K-Seal ST5516 is a 16 oz heavy-duty coolant leak repair solution designed for rapid, one-step sealing of leaks in water-cooled engines. Compatible with all antifreeze types and requiring no flushing, it’s engineered for large commercial and agricultural vehicles, ensuring durable performance and maintaining engine cooling efficiency. ## Description Buy K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required: Antifreezes & Coolants - desertcart.com ✓ FREE DELIVERY possible on eligible purchases ## Features - FIX IT FAST: Our multi-purpose solution works in minutes to quickly seal leaks in the radiator, head gasket, freeze plugs, block, heater matrix & water pump of heavy duty vehicles. Fixes most leaks in water-cooled engines - STOP HOLES & CRACKS: With 1 step our unique formula will seek out each hole & crack, sealing them, without any adverse impact on the efficiency of your engine cooling - HEAVY DUTY PERFORMANCE: Engineered for large engines & industrial use; suitable for commercial or agricultural vehicles. Compatible with all types of antifreeze coolant ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B002BJEG3U | | Best Sellers Rank | #9,078 in Automotive ( See Top 100 in Automotive ) #43 in Antifreezes & Coolants | | Brand | K-Seal | | Customer Reviews | 4.4 4.4 out of 5 stars (1,652) | | Date First Available | May 29, 2009 | | Is Discontinued By Manufacturer | No | | Item Weight | 1.19 pounds | | Item model number | ST5516HD | | Manufacturer | Solv-Tec | | Manufacturer Part Number | ST5516 | | Model | ST5516HD | | Product Dimensions | 5.9 x 4.1 x 1.9 inches | ## Images ![K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - Image 1](https://m.media-amazon.com/images/I/71MW1pVoIUL.jpg) ![K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - Image 2](https://m.media-amazon.com/images/I/711qxdv5xHL.jpg) ![K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - Image 3](https://m.media-amazon.com/images/I/81Js2ztN+RL.jpg) ![K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - Image 4](https://m.media-amazon.com/images/I/81367JDTP5L.jpg) ![K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - Image 5](https://m.media-amazon.com/images/I/81sAcKFs57L.jpg) ## Questions & Answers **Q: Does it work on potentially warped heads** A: No idea **Q: how much do i need to pour in a diesel 1 ton cummins** A: You need this one bottle for a Dodge 3500 hd. I have this one bottle in my HD Freightliner 330hp MBZ engine hauling freight (54,000 lbs cap) 6 days a week and it stopped my coolant leak in the engine bay and heater core with no blockage and no. My opinion, Many reviews say products dont work BECAUSE most people dont take care of their equipment and their vehicles are old, high mileage and no maintenance done. None of the add to a tank products are as good as replacing with new parts but thats expensive, we get it. This may or may not fix your problem but its a low cost gamble with a high probability of success. Dont listen to the negative reviews. If the problem comes back, your damage was too far gone and in need of replacement anyway. **Q: Will this work with aluminum heads?** A: It works equally well with cast iron or aluminum. Great Stuff. Not a long-term solution, but it will buy you a lot of time. **Q: Tried using alumaseal, which isn't working. will i need to flush the system before using the k-seal?** A: I used the HD Truck bottle on my 1998 GEO Tracker ( used 1/3 of the bottle ) of K-Seal and it worked. I have used so many to no avail. To answer your question, I must have @ least 3 to 4 other sealers in my colling system when I added K-Seal. It's been almost a year & no adverse effects having not flushed my radiator. Should I have flushed the radiator & the system? Yes, I should have. ## Frequently Bought Together - K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Permanent Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - PEAK 50/50 Prediluted Antifreeze and Coolant for All Engine Cooling Systems - K-Seal ST3501 Pour and Go Head Gasket Sealer, 16oz, Permanent Repair for Blown Head Gaskets, Cracked Heads and Blocks --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/8435813-k-seal-st5516-heavy-duty-multi-purpose-one-step-coolant](https://www.desertcart.hr/products/8435813-k-seal-st5516-heavy-duty-multi-purpose-one-step-coolant) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-06-21*