---
product_id: 8435813
title: "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"
price: "AED 127"
currency: AED
in_stock: true
reviews_count: 8
url: https://www.desertcart.ae/products/8435813-k-seal-st5516-heavy-duty-multi-purpose-one-step-permanent
store_origin: AE
region: United Arab Emirates
---

# One-step, no flushing needed Heavy-duty for large engines Seals leaks in minutes 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

**Price:** AED 127
**Availability:** ✅ In Stock

## Summary

> 🚀 Seal leaks like a pro—fast, permanent, and hassle-free!

## Quick Answers

- **What is this?** 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
- **How much does it cost?** AED 127 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ae](https://www.desertcart.ae/products/8435813-k-seal-st5516-heavy-duty-multi-purpose-one-step-permanent)

## 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

- • **Instant Leak Fix:** Stop coolant leaks fast with a formula that seals holes & cracks in minutes.
- • **Effortless Application:** Shake, pour, and go—no draining or flushing required for busy pros.
- • **Universal Compatibility:** Works seamlessly with all antifreeze types across commercial & agricultural vehicles.
- • **Engineered for Heavy-Duty:** Designed for large engines, from trucks to tractors, ensuring permanent repairs.
- • **Trusted Professional Grade:** Mechanic-approved, non-corrosive, and independently tested for lasting reliability.

## Overview

K-Seal ST5516 Heavy-Duty 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, it requires no draining or flushing and is engineered for heavy-duty commercial and agricultural engines. Trusted by mechanics worldwide, it delivers fast, durable repairs that extend engine life and prevent costly downtime.

## Description

Experience the ultimate solution to coolant leaks with the K-Seal ST5516 HD, 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. This heavy-duty sealer was designed specifically for HGVs, tractors, heavy plant and other commercial vehicles. The K-Seal ST5516 HD, 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 ST5516 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: Worked Perfectly! - Vehicle leaking coolant, about 1gal per 1,000 mi driven. Dealer diagnosed as jiffy tight fittings on turbos with a repair estimate of $3,300. 2015 Ford F-150 - 3.5L Ecoboost with 140K miles so didn't want to put that kind of cash into a high mileage vehicle. Added as directed and leaks stopped immediately. 1K miles later, coolant level in the overflow tank has not gone down at all.
Review: Works well - Good product

## 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 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, permanently sealing them, without any adverse impact on the efficiency of your engine cooling
- EASY TO USE: K-Seal couldn't be simpler & requires no draining or flushing; just shake, pour & go - shake the bottle, add the fluid to your coolant system & run your engine as normal
- HEAVY DUTY PERFORMANCE: Engineered for large engines & industrial use; suitable for commercial or agricultural vehicles. A permanent repair for the lifetime of the engine. Compatible with all types of antifreeze coolant
- PROFESSIONAL-GRADE RELIABILITY: Trusted by mechanics, our non-corrosive sealer delivers a durable & long-lasting repair, without clogging your cooling system. 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 | B002BJEG3U |
| Best Sellers Rank | #9,283 in Automotive ( See Top 100 in Automotive ) #44 in Antifreezes & Coolants |
| Brand | K-Seal |
| Customer Reviews | 4.4 4.4 out of 5 stars (1,611) |
| 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 Permanent Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required - Image 1](https://m.media-amazon.com/images/I/71gy7ybxZsL.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

### ⭐⭐⭐⭐⭐ Worked Perfectly!
*by J***S on December 17, 2025*

Vehicle leaking coolant, about 1gal per 1,000 mi driven. Dealer diagnosed as jiffy tight fittings on turbos with a repair estimate of $3,300. 2015 Ford F-150 - 3.5L Ecoboost with 140K miles so didn't want to put that kind of cash into a high mileage vehicle. Added as directed and leaks stopped immediately. 1K miles later, coolant level in the overflow tank has not gone down at all.

### ⭐⭐⭐⭐⭐ Works well
*by J***K on March 17, 2026*

Good product

### ⭐⭐⭐⭐⭐ 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!

## 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

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*Product available on Desertcart United Arab Emirates*
*Store origin: AE*
*Last updated: 2026-04-23*