---
product_id: 50154348
title: "Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red"
brand: "liqui moly"
price: "€ 38.60"
currency: EUR
in_stock: true
reviews_count: 8
category: "Liqui Moly"
url: https://www.desertcart.it/products/50154348-pro-line-radiator-stop-leak-k-250-ml-cooler-additive
store_origin: IT
region: Italy
---

# Treats up to 40L coolant Works within 10 minutes Seals hairline cracks & leaks Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red

**Brand:** liqui moly
**Price:** € 38.60
**Availability:** ✅ In Stock

## Summary

> 🚗💨 Seal the deal before your engine feels the heat!

## Quick Answers

- **What is this?** Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red by liqui moly
- **How much does it cost?** € 38.60 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.it](https://www.desertcart.it/products/50154348-pro-line-radiator-stop-leak-k-250-ml-cooler-additive)

## Best For

- liqui moly enthusiasts

## Why This Product

- Trusted liqui moly brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Compact & Efficient:** 250 ml treats up to 40 liters of coolant, maximizing value and convenience
- • **Long-Lasting Protection:** Keeps your cooling system sealed for months, avoiding costly repairs
- • **Easy Application Process:** Just shake, pour at operating temp, and run engine for 10 minutes
- • **Instant Leak Sealing Power:** Stops small leaks from stone chips and porous soldering points fast
- • **Universal Cooling Circuit Compatibility:** Perfect for cars, commercial vehicles, buses, and water-filtered systems

## Overview

LIQUI MOLY Pro-Line Radiator Stop Leak K is a high-performance coolant additive designed to quickly seal small leaks and cracks in vehicle cooling systems. Suitable for passenger cars, commercial vehicles, and buses, this 250 ml formula treats up to 40 liters of coolant and works effectively within 10 minutes of application, helping you avoid expensive repairs and maintain optimal engine temperature.

## Description

LIQUI MOLY Pro-Line Radiator Stop Leak K | 250 ml | Cooler additive | SKU: 5178, red : desertcart.co.uk: Automotive

Review: Highly recommended 👌 - Easy to use and work done 💯, Very happy and value for money.
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.
- Small leaks caused by stone impacts, porous soldering points and hairline cracks in the cooling simple are easy to localize (one notices that the cooling water level is sinking).
- Used for sealing small leaks in cooling circuits of passenger motor vehicles, commercial vehicles and buses. Also suited for cooling water circuits equipped with water filters.
- Shake container before use. Start up the heater. With the engine running, pour the contents into the coolant at operating temperature and allow the engine to continue running for at least a further 10 minutes.
- Contents will treat up to 40 liters of coolant.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B004FPUUSS |
| Best Sellers Rank | 4,837 in Automotive ( See Top 100 in Automotive ) 57 in Fillers, Adhesives & Sealants |
| Brand | Liqui Moly |
| Customer Reviews | 4.5 4.5 out of 5 stars (2,767) |
| 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)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Highly recommended 👌
*by M***N on 18 January 2026*

Easy to use and work done 💯, Very happy and value for money.

### ⭐⭐⭐⭐⭐ 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!

### ⭐⭐⭐⭐⭐ Leak stopper
*by S***S on 25 January 2026*

Did the job

## 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

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*Product available on Desertcart Italy*
*Store origin: IT*
*Last updated: 2026-03-07*