--- product_id: 5618885 title: "ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required" brand: "k-seal" price: "€ 29.30" currency: EUR in_stock: true reviews_count: 8 category: "K Seal" url: https://www.desertcart.gr/products/5618885-st5501-multi-purpose-one-step-permanent-coolant-leak-repair-8oz store_origin: GR region: Greece --- # One-step, no flushing needed Seals leaks in minutes Permanent, professional-grade fix ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required **Brand:** k-seal **Price:** € 29.30 **Availability:** ✅ In Stock ## Summary > 🛠️ Fix leaks fast, drive worry-free—because your engine deserves the best! ## Quick Answers - **What is this?** ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required by k-seal - **How much does it cost?** € 29.30 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/products/5618885-st5501-multi-purpose-one-step-permanent-coolant-leak-repair-8oz) ## 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:** Fixes radiator, head gasket & more in minutes—no downtime. - • **Effortless Application:** Just shake, pour & go—no draining or flushing required. - • **Universal Compatibility:** Works with all antifreeze types & up to 12-cylinder engines. - • **Long-Lasting Reliability:** Trusted by mechanics worldwide with ASTM D3147 certification. - • **Cost-Effective Engine Savior:** Save thousands on repairs—permanent seal for your cooling system. ## Overview K-Seal ST5501 is a professional-grade, one-step coolant leak repair solution that permanently seals leaks in radiators, head gaskets, freeze plugs, and more. Compatible with all antifreeze types and suitable for cars and light trucks up to 12 cylinders, it requires no draining or flushing—just shake, pour, and go. Independently tested and trusted by mechanics worldwide, it offers a cost-effective, durable fix that extends engine life and prevents costly repairs. ## Description Experience the ultimate solution to coolant leaks with the K-Seal ST5501, a multi-purpose, one-step permanent coolant leak repair. Our powerful formula works seamlessly with all antifreeze, making it a universal fit type for all your needs. No need for draining or flushing your system. The K-Seal ST5501, also known as a head gasket stop leak, works by sealing leaks efficiently and permanently. It also doubles as a radiator stop leak, effectively putting an end to any leaks in your radiator. The permanent leak sealer is easy to use - just shake, pour, and go. This product excels in fixing cracks and leaks in several components including the radiator, head gasket, freeze plugs, cylinder heads, heater core, water pump casing, and engine blocks. With a single 8 fluid ounce bottle of our coolant leak sealer, you can treat up to 20 quarts cooling capacity. This heavy duty stop leak sealant is a must-have for all your coolant leak issues. So, forget your coolant leak worries with the K-Seal ST5501 HD. Experience the power of a seal stop leak that stops leaks permanently, offering peace of mind and extended life for your vehicle's cooling system. Trust the K-Seal coolant leak repair for a lasting solution to all your coolant leak problems. Review: This stuff is liquid gold, only cheaper! Try it! - I have a 2000 Pontiac Grand AM GT V6 3400 engine, bought the car new from the dealer. A few years back the engine developed a coolant leak in the lower intake manifold, discovered oil in the coolant and needed to fill the radiator tank every couple of weeks. I had a mechanic remove the intake and replace the gaskets; he also suggest I have the heads removed and new head gaskets installed while he had it apart. $1,500 later it was back together and running great, no more leaks. Fast forward about 10K miles and a little over a year later, out of warranty I may add, the engine would smell of coolant and started to leak externally. I was going through a gallon a coolant every couple weeks. Take into account this car has about 100K miles and has a market value of about $1,800. I wasn't going to throw anymore money after bad. So I kept driving it, but one morning I started it up cold and the engine began to miss on 1 or 2 cylinders, the check engine was flashing, indicated the misfiring cylinders. I towed it to another mechanic to see what the cause was, turns out the head gasket was blown this time, compression test proved his theory, he suggested I get another engine from a junked used car and try my luck. That would cost about $3,000 with parts and labor. Not about to throw any more money away, I had the car towed back to my house where it sat for a few months. Not sure what to do with this car, body, paint and interior was in excellent condition, oil was always changed with Mobile 1, it was a well maintained car, was a shame to see it there dead in the driveway. Just had new tires and brakes installed prior to the coolant leak. One day I ran across an article promoting K-Seal, after reading the great reviews here on desertcart, I figured what the heck. It was either call the junk yard and have them pick up the car or spend less than the cost of lunch and give it a shot. Can't believe how easy it was to do, I pulled the radiator hose from the engine block, poured in the K-Seal and reinstalled the hose. The directions state you do not have to drain the coolant like other brands require. Started the car up, and of course the engine was misfiring and check engine light began to flash like before. I let it idle for a few minutes to warm up, when it got to operating temperature, I took it for a drive around the neighborhood. Within about a mile of driving, the engine smoothed out and the CE light went dark. Drove around for another 20 minutes and returned home. I parked the car and check underneath to see if the coolant was leaking like before, to my surprise it had stopped! I let the engine cool and topped off the coolant reservoir with fresh antifreeze until full. I decide to drive the car to work the next day, a 35 miles commute one way into the city, in the middle of summer, ran flawless. Wow! Absolutely no problems since the K-Seal treatment. I have been driving the car now for 7 months and about 6K miles. The coolant hasn't leak a bit and the car runs flawless.Even my mechanic can't believe this stuff actually worked. I am a believer and have since told many people of my experience with this product. Had a buddy with a similar issue with his beloved 2 DR Accord V6, fixed his leak too! I normally don't spend the time to write reviews, but this product truly has made a believer out of me. What do you have to lose? I almost threw away my car, and for a measly few dollars it is now back on the road better than ever. Thank you K-Seal ! I want to add that after reading the one star reviews on this forum that these people were not using the product as intended. It is designed to very small leaks like in gaskets and cracks in the engine block of heads. It needs high heat to cure the fine copper powder that forms a new gasket. If you have a large leak in a radiator, heater core or hose, it's probably not going to work for very long if at all, better off replacing them. Now head gaskets, yes give it a shot! UPDATE: 9/9/16 Still no leaks, I've clocked 20K+ miles on K-Seal with no issues. Hoping for another 20K... buy this stuff. UPDATE: 1/11/17 Well, the engine miss has returned, anti-freeze is disappearing again, head gasket is leaking again. Just poured another bottle of K-Seal in again, within 5 minutes the leak is repaired again. This stuff is great, my old beater is good for another 20K I hope. Money saved again! My mileage on the first repair was 23K miles, not bad for a $11 fix. Review: Worked for me and saved me $$$ - I have a 25 year old Nissan Pathfinder SUV with over 180000 miles that still runs like it did when I drove it off the dealer lot. Last year, it developed a small coolant leak at a connection to a coolant line between the engine and the firewall. The only way to find it was with a coolant system pressure tester. Getting to that connection to replace the hose requires taking off almost everything above the cylinder heads on the engine--many thousands of dollars if I paid a mechanic, days of difficult work for me, or time to sell for most people. I really didn't have anything to lose giving this stuff a try. And it worked! It stopped the leak with no discernable affect on my cooling system or engine. I am writing this review one year later, and the leak is still sealed. No loss of coolant since, and the engine runs at the same operating temp as it always has. Thank you K-Seal! ## Features - FIX IT FAST: Our multi-purpose solution works in minutes to quickly & permanently seal leaks in the radiator, head gasket, freeze plugs, block, heater matrix & water pump. Fixes most leaks in water-cooled engines - STOP HOLES & CRACKS: With just 1 step our unique formula will seek out each hole & crack, permanently sealing them, without any adverse impact on the efficiency of your engine cooling - EASY TO USE: K-Seal couldn't be simpler to use & requires no draining or flushing; just shake, pour & go - shake the bottle, add the fluid to your coolant system & run your engine as normal - VERSATILE COMPATIBILITY: Compatible with all types of antifreeze coolant. Suitable for use in both cars & light trucks with up to 12 cylinders. A permanent repair for the lifetime of the engine - PROFESSIONAL-GRADE RELIABILITY: Trusted by mechanics, our sealer delivers a durable & long-lasting repair. A cost-effective solution to engine coolant leaks, enhancing the reliability & performance of your vehicle’s cooling system. We've sold millions worldwide & are independently verified by university testing to meet ASTM D3147 ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B001QT9KO6 | | Best Sellers Rank | #1,549 in Automotive ( See Top 100 in Automotive ) #1 in Cooling System Additives | | Brand Name | K-Seal | | Color | BLUE | | Compatible Material | All Types of Antifreeze / Coolant and Other Additives | | Customer Reviews | 4.3 4.3 out of 5 stars (13,125) | | Global Trade Identification Number | 05060002968017 | | Included Components | K-Seal ST5501 Multi Purpose One Step Permanent Coolant Leak Repair | | Item Dimensions | 3.5 x 1.5 x 4.5 inches | | Item Form | Liquid | | Item Type Name | Engine Coolant Leak Repair | | Item Weight | 0.26 Kilograms | | Manufacturer | Solv-Tec | | Material Type | Plastic | | Model | ST5501 | | Number of Items | 1 | | Part Number | ST5501 | | Style Name | Compact | | Surface Recommendation | Metal | | UPC | 367157659506 812646010004 | | Unit Count | 1.0 Count | | Warranty Description | When K-Seal makes a repair we guarantee it will be permanent | | Water Resistance Level | Waterproof | ## Product Details - **Brand:** K-Seal - **Item Weight:** 0.26 Kilograms - **Item dimensions L x W x H:** 3.5 x 1.5 x 4.5 inches - **Material:** Plastic - **Style:** Compact ## Images ![ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - Image 1](https://m.media-amazon.com/images/I/71+jNF250SL.jpg) ## Questions & Answers **Q: will this work for leakey gaskets?** A: It is designed to work on leaky gaskets. If you have a small leak this product might be an easy and cheap fix. It did not work for me. Perhaps my leak was too large. It is hard to tell. **Q: Does it discolor the antifreeze? Thanks** A: Unfortunately I can't say. I have a GM vehicle that uses the orangish color engine coolant and it and this product are so close in color it's hard to say if it would discolor the usual green-colored coolant found in non-GM vehicles. The other challenge is that I can only look at the coolant through an overflow reservoir and it's so dark when I look inside (I have to use an LED flashlight to see it adequately) that it would be hard to tell if there was any discoloration. **Q: Can you use this in a 2013 escape?** A: You can use it anywhere. It's kept my 1998 Chevy Lumina going over 2 years with almost 178,000 miles on it! **Q: can you mix this with barstop if you all ready put that in the radiator?** A: I did mix this with Irontite All Weather Seal. Did the K-seal first. Irontite a week later. Just to be sure. Since they both said it can remain in the system. Two weeks, still good. ## Customer Reviews ### ⭐⭐⭐⭐⭐ This stuff is liquid gold, only cheaper! Try it! *by R***T on December 1, 2015* I have a 2000 Pontiac Grand AM GT V6 3400 engine, bought the car new from the dealer. A few years back the engine developed a coolant leak in the lower intake manifold, discovered oil in the coolant and needed to fill the radiator tank every couple of weeks. I had a mechanic remove the intake and replace the gaskets; he also suggest I have the heads removed and new head gaskets installed while he had it apart. $1,500 later it was back together and running great, no more leaks. Fast forward about 10K miles and a little over a year later, out of warranty I may add, the engine would smell of coolant and started to leak externally. I was going through a gallon a coolant every couple weeks. Take into account this car has about 100K miles and has a market value of about $1,800. I wasn't going to throw anymore money after bad. So I kept driving it, but one morning I started it up cold and the engine began to miss on 1 or 2 cylinders, the check engine was flashing, indicated the misfiring cylinders. I towed it to another mechanic to see what the cause was, turns out the head gasket was blown this time, compression test proved his theory, he suggested I get another engine from a junked used car and try my luck. That would cost about $3,000 with parts and labor. Not about to throw any more money away, I had the car towed back to my house where it sat for a few months. Not sure what to do with this car, body, paint and interior was in excellent condition, oil was always changed with Mobile 1, it was a well maintained car, was a shame to see it there dead in the driveway. Just had new tires and brakes installed prior to the coolant leak. One day I ran across an article promoting K-Seal, after reading the great reviews here on Amazon, I figured what the heck. It was either call the junk yard and have them pick up the car or spend less than the cost of lunch and give it a shot. Can't believe how easy it was to do, I pulled the radiator hose from the engine block, poured in the K-Seal and reinstalled the hose. The directions state you do not have to drain the coolant like other brands require. Started the car up, and of course the engine was misfiring and check engine light began to flash like before. I let it idle for a few minutes to warm up, when it got to operating temperature, I took it for a drive around the neighborhood. Within about a mile of driving, the engine smoothed out and the CE light went dark. Drove around for another 20 minutes and returned home. I parked the car and check underneath to see if the coolant was leaking like before, to my surprise it had stopped! I let the engine cool and topped off the coolant reservoir with fresh antifreeze until full. I decide to drive the car to work the next day, a 35 miles commute one way into the city, in the middle of summer, ran flawless. Wow! Absolutely no problems since the K-Seal treatment. I have been driving the car now for 7 months and about 6K miles. The coolant hasn't leak a bit and the car runs flawless.Even my mechanic can't believe this stuff actually worked. I am a believer and have since told many people of my experience with this product. Had a buddy with a similar issue with his beloved 2 DR Accord V6, fixed his leak too! I normally don't spend the time to write reviews, but this product truly has made a believer out of me. What do you have to lose? I almost threw away my car, and for a measly few dollars it is now back on the road better than ever. Thank you K-Seal ! I want to add that after reading the one star reviews on this forum that these people were not using the product as intended. It is designed to very small leaks like in gaskets and cracks in the engine block of heads. It needs high heat to cure the fine copper powder that forms a new gasket. If you have a large leak in a radiator, heater core or hose, it's probably not going to work for very long if at all, better off replacing them. Now head gaskets, yes give it a shot! UPDATE: 9/9/16 Still no leaks, I've clocked 20K+ miles on K-Seal with no issues. Hoping for another 20K... buy this stuff. UPDATE: 1/11/17 Well, the engine miss has returned, anti-freeze is disappearing again, head gasket is leaking again. Just poured another bottle of K-Seal in again, within 5 minutes the leak is repaired again. This stuff is great, my old beater is good for another 20K I hope. Money saved again! My mileage on the first repair was 23K miles, not bad for a $11 fix. ### ⭐⭐⭐⭐⭐ Worked for me and saved me $$$ *by R***. on September 12, 2025* I have a 25 year old Nissan Pathfinder SUV with over 180000 miles that still runs like it did when I drove it off the dealer lot. Last year, it developed a small coolant leak at a connection to a coolant line between the engine and the firewall. The only way to find it was with a coolant system pressure tester. Getting to that connection to replace the hose requires taking off almost everything above the cylinder heads on the engine--many thousands of dollars if I paid a mechanic, days of difficult work for me, or time to sell for most people. I really didn't have anything to lose giving this stuff a try. And it worked! It stopped the leak with no discernable affect on my cooling system or engine. I am writing this review one year later, and the leak is still sealed. No loss of coolant since, and the engine runs at the same operating temp as it always has. Thank you K-Seal! ### ⭐⭐⭐⭐⭐ Worth a Try! *by C***K on March 8, 2025* Tried this after a good couple of years of dealing with a chronic overheating issue in my Saturn Aura. Considering that the repair cost at a garage would be well over the current value of the car I basically dumped distilled water and coolant into the reservoir whenever it started getting hot. I noticed a strong coolant smell every time the thermostat started fluctuating on the dash. So I decided to try this stuff recently. I noticed the difference on a grocery run; aside from the lack of overheating issues, the lack of the coolant smell when parked and the fans going on at full blast! A few trips to the store later the repair seems to have held up, the heater is working normally again, no wild fluctuating thermostat. It may be a temporary repair but if it lasts a few months or forever it's worth a try if you have this issue with your vehicle. UPDATE: 8 months later it still holds up. UPDATE #2: Leak returned. Attempted to fix with this again and does not seem to work. Again, good for temporary repair, it held up for over a year, depends on how severe the hole in the system is I suppose? ## Frequently Bought Together - K-Seal ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, 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.gr/products/5618885-st5501-multi-purpose-one-step-permanent-coolant-leak-repair-8oz](https://www.desertcart.gr/products/5618885-st5501-multi-purpose-one-step-permanent-coolant-leak-repair-8oz) --- *Product available on Desertcart Greece* *Store origin: GR* *Last updated: 2026-04-24*