--- product_id: 8435813 title: "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: "NT$1797" currency: TWD in_stock: true reviews_count: 13 category: "K Seal" url: https://www.desertcart.tw/products/8435813-st5516-heavy-duty-multi-purpose-one-step-coolant-leak-repair store_origin: TW region: Taiwan --- # Heavy-duty, industrial strength Seals leaks in minutes One-step, no flushing needed 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:** NT$1797 **Availability:** ✅ In Stock ## Summary > 🚀 Seal it fast, drive with confidence—no leaks, no limits! ## Quick Answers - **What is this?** 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?** NT$1797 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.tw](https://www.desertcart.tw/products/8435813-st5516-heavy-duty-multi-purpose-one-step-coolant-leak-repair) ## 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 Sealing:** Fix radiator, head gasket & more in minutes—no downtime, no hassle. - • **One-Step Application:** Pour and go—no flushing required, saving you time and effort. - • **Heavy-Duty Engine Ready:** Engineered for commercial, agricultural & large engines to keep you moving. - • **Invisible Armor for Your Engine:** Seeks out and seals holes & cracks without compromising cooling efficiency. - • **Universal Coolant Compatibility:** Mixes seamlessly with all antifreeze types for ultimate convenience. ## 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, it requires no flushing and is engineered for large commercial and agricultural vehicles, ensuring durable performance without impacting 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 Review: Works really well on minor leaks - This stuff really works. Had a minor leak in the radiator. Follow the directions as they were written on container leaked up within a couple of days.. very easy to use Review: It'll work on anything but bullet holes I think. - I just concluded a 7,000 mile drive from Georgia to Oklahoma, then to Cali and from there, Washington state and then back to Georgia in my 2002 Chevy Tahoe while hauling a 21' toy hauler heavy laden with toys. My Tahoe has an aftermarket radiator that produced a pinhole leak during travel. I couldn't directly locate the leak nor was I able to just replace the radiator as I was traveling. So I considered using a radiator stop leak but hesitant to do so as I didn't want to plug up my cooling system at all. I found this product and due to the reviews, decided to try it. It worked almost immediately after running the engine for a while to circulate the solution. And it still has not shown signs of leaking and no affect of the cooling capabilities either. I highly recommend this product! ## 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 | #13,102 in Automotive ( See Top 100 in Automotive ) #51 in Antifreezes & Coolants | | Brand | K-Seal | | Customer Reviews | 4.4 4.4 out of 5 stars (1,677) | | Date First Available | May 29, 2009 | | Item Weight | 1.17 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 ![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) ![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) ![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) ![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) ![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. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works really well on minor leaks *by W***E on June 28, 2026* This stuff really works. Had a minor leak in the radiator. Follow the directions as they were written on container leaked up within a couple of days.. very easy to use ### ⭐⭐⭐⭐⭐ It'll work on anything but bullet holes I think. *by I***N on November 21, 2025* I just concluded a 7,000 mile drive from Georgia to Oklahoma, then to Cali and from there, Washington state and then back to Georgia in my 2002 Chevy Tahoe while hauling a 21' toy hauler heavy laden with toys. My Tahoe has an aftermarket radiator that produced a pinhole leak during travel. I couldn't directly locate the leak nor was I able to just replace the radiator as I was traveling. So I considered using a radiator stop leak but hesitant to do so as I didn't want to plug up my cooling system at all. I found this product and due to the reviews, decided to try it. It worked almost immediately after running the engine for a while to circulate the solution. And it still has not shown signs of leaking and no affect of the cooling capabilities either. I highly recommend this product! ### ⭐⭐⭐⭐⭐ This stuff save me about $20K! It works! *by M***S on August 14, 2025* I waited 5 days to write this review on my birthday. Mainly because I am so impressed with this product and I didn't know that it would hold. I'm not getting paid for this review and I rarely write reviews. A little history. I own a 2007 Mercedes E-63. This car is a beast and is a joy to drive. The dealership diagnosed a blown head gasket on the car. The report shows coolant mixed with the engine oil. My oil almost looked like a mocha espresso. A very bad sign. The car was immediately overheating. I was adding antifreeze every day. The dealership estimated repairs to start at $15K but could easily rise to $25K. Once the top of the motor is opened up I'm sure they would recommend new cams (4), new cam adjusters and of course new seals. A new crate engine for this car from Mercedes-Benz costs $57,000.00. After carefully reading the directions I added coolant with the bottle of K-seal after shaking it for 1 minute. Then I drove the car normally for 20-25 minutes. The car came up to temperature and stayed there. It didn't overheat! After feeling terribly about having to sell the car as a mechanic's special or donating the car I can instead enjoy driving the car daily. I did end up changing the oil 3 times before it didn't appear to have any more coolant in it. Thanks K-seal! ## 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.tw/products/8435813-st5516-heavy-duty-multi-purpose-one-step-coolant-leak-repair](https://www.desertcart.tw/products/8435813-st5516-heavy-duty-multi-purpose-one-step-coolant-leak-repair) --- *Product available on Desertcart Taiwan* *Store origin: TW* *Last updated: 2026-08-12*