---
product_id: 6911365
title: "K&W 401224 FiberLock Head Gasket & Block Repair - 32 Fl Oz"
brand: "k & w"
price: "$124.74"
currency: USD
in_stock: true
reviews_count: 6
category: "K & W"
url: https://www.desertcart.us/products/6911365-k-and-w-401224-fiberlock-head-gasket-and-block-repair
store_origin: US
region: United States of America
---

# Repairs leaks in ≤30 mins Lowers engine operating temp Military-strength fiber tech K&W 401224 FiberLock Head Gasket & Block Repair - 32 Fl Oz

**Brand:** k & w
**Price:** $124.74
**Availability:** ✅ In Stock

## Summary

> 🛠️ Fix it once, drive forever — the ultimate coolant leak solution!

## Quick Answers

- **What is this?** K&W 401224 FiberLock Head Gasket & Block Repair - 32 Fl Oz by k & w
- **How much does it cost?** $124.74 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/6911365-k-and-w-401224-fiberlock-head-gasket-and-block-repair)

## Best For

- k & w enthusiasts

## Why This Product

- Trusted k & w brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Cool-X Conditioner:** Reduces engine heat for enhanced performance and longevity.
- • **Pour & Go Simplicity:** No draining needed—just add and drive.
- • **Nanotech-Powered Repair:** Seals microscopic cracks with advanced fiber webbing.
- • **Trusted by Pros & DIYers:** Mechanic-recommended formula with 4.1-star reliability.
- • **Permanent Leak Fix in 30 Minutes:** Stop coolant loss fast with a proven, permanent seal.

## Overview

K&W 401224 FiberLock Head Gasket & Block Repair is a 32 fl oz advanced coolant system sealant that permanently repairs leaks in 30 minutes or less. Featuring military-strength fibers and nanotechnology, it seals cracks and holes without draining your cooling system, while lowering engine temperature. Trusted by mechanics and DIY enthusiasts alike, this premium formula is compatible with all antifreeze types and designed to keep your engine running smoothly and leak-free.

## Description

Permanent pour 'n go head gasket & block repair compatible with all types of antifreeze. Repairs cooling system leaks w/3 unique technologies: military-strength fibers nanotechnology & Cool-X Conditioner-the ultimate solution for all coolant leaks.

Review: it worked - used this to fix a hairline crack somewhere in the block or timing cover. so i have a 2010 jeep grand cherokee with a 5.7 hemi motor, bought it real cheap due to haveing a head gasket issue due to an overheat , im a tech for 40 years and know these hemi's well ,i did all the work myself , replaced both head gasket heads were sent out and resurfaced and i did a valve job , the motor fired right up and ran perfect when finished , however i noticed my coolant level was dropping slowley with know external leaks , after investigating i found coolant in my catch can so know i knew that it was getting into the crankcase, after i drained out about 8 0z of oil from the sump i saw a little bit of coolant in there but not to bad and not a lot . the coolant seemed to be entering the crankcase but more as a vapor if anything because most was in my catch can. there was a hairline crack somewhere . i decided to try this but was very skeptical . and low and behold it worked ! i couldn't believe it , no more coolant in my catch can or in the bottom of oil sump , i was amazed it actually worked , its been a year now with about 7k miles and still holding up! no coolant loss ,no heater core or radiator issues, i did put a new thermostat in it after about 100 miles running on it and found some hardened material around it but i wasn't worried about it after i installed a new one . i recommend this if you have a small leak due to a crack .
Review: Works like a charm so long as you can follow the instructions. - I have a suspicion that the bad reviews of this product are coming from people who are using it incorrectly. I had a blown head gasket (confirmed by repair shop when they replaced my timing belt, water pump, and thermostat) on a 1995 1.5L Honda Civic engine. The only reason I picked up a bottle of this sealant was because the mechanic recommended it after I told him that I couldn't afford a $500 dollar repair bill for replacing the head gasket. The mechanic told me that he'd used this stuff before and that it was pretty much the only head gasket sealant on the market that he'd ever seen work and told me that he would never recommend any other but this stuff actually works. So I ordered a bottle and gave it a try. The first thing I noticed was that the instructions clearly state that you should read the entire label before starting and that you should know exactly how much fluid your radiator and engine block hold and to use a specific amount based on the volume. It also clearly states that if your water pump or thermostat are not properly working that it will not work properly and could cause uneven distribution of the product. It states clearly on the label to use the proper amount and to add it very slowly into the properly diluted radiator fluid and not to add the product until the fluid level is high enough not to touch the fins on the inside of the radiator. After doing just that, letting the engine run and the coolant cycle and then topping it off, and then letting it idle for over 15 minutes with the heat on, I could already tell that the engine was running as smoothly as it did before the blown gasket. After several days of driving, it no longer overheats, no longer produces white smoke from the coolant leaking through the gasket into the engine, no long is leaking oil into the coolant and is no longer running rough. The stuff is very clumpy and can look worrying but when the proper amount (for me 1/3 a bottle) is added to properly mixed 50/50 fluid, it cycles through and smooths out. I plan on letting it stay in the engine until I get ready to flush the radiator out and get the rest off the product out but the bottle clearly states that you can leave it in without flushing and that it will not cause clogging or sludge. So far it has work perfectly and seems to have sealed the gasket completely but even if it does begin to leak slightly, it says that you can add more which I plan to do if it does, though so far it after 4 days of daily commuting for 36 miles, it has had no problems and works perfectly. I'd recommend it to anyone who can properly follow instructions but I would imagine that if you added it to the wrong coolant type or mixture or if you added way more than was intended that it would cause major problems with clogging up your system. Having a new water pump probably also helps, as I would imagine that if your water pump wasn't properly cycling the stuff that it would clog up in the system and prevent the sealant from reaching the leaking points and possibly clog up the radiator or heater coils. Use it as intended and it should turn out just fine.

## Features

- PERMANENT FIX: Seals larger holes with less fluid loss than competitive products to permanently repair leaks in 30 minutes or less.
- EASY TO USE: Our easy; pour-in formula allows you to fix leaks without having to drain your cooling system.
- PREMIUM FORMULA: Contains military strength fibers to create multi-layer repair over cracks with a web-like weave. Nanotechnology permanently fixes the smallest cracks and crevices. Lowers operating temperature as it circulates through cooling system.
- PRODUCT SPECIFICATIONS: CRC FiberLock Head Gasket & Block Repair is available in a 32 fl oz bottle.
- CRC INDUSTRIES: A market leader that offers impeccably designed chemical solutions to maintain; protect and repair different marine; heavy-duty motor vehicles; industrial-grade engines; household tools and electrical equipment.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B006OW2PIS |
| Best Sellers Rank | #36,342 in Automotive ( See Top 100 in Automotive ) #45 in Gasket Sealers |
| Brand | K & W |
| Color | gray |
| Customer Reviews | 4.1 4.1 out of 5 stars (883) |
| Date First Available | July 7, 2004 |
| Global Trade Identification Number | 00078372012242 |
| Is Discontinued By Manufacturer | Yes |
| Item Weight | 2.44 pounds |
| Item model number | 401224 |
| Manufacturer | CRC |
| Manufacturer Part Number | 401224 |
| Model | 401224-6 |
| Product Dimensions | 3.4 x 3.4 x 9.54 inches |
| UPC | 078372012242 |
| Unit Count | 1 Count |

## Product Details

- **Brand:** K & W
- **Color:** gray
- **Manufacturer:** CRC
- **UPC:** 078372012242
- **Unit Count:** 1 Count

## Images

![K&W 401224 FiberLock Head Gasket & Block Repair - 32 Fl Oz - Image 1](https://m.media-amazon.com/images/I/61uA-QMSAsL.jpg)

## Questions & Answers

**Q: How do I clean this crap out of my radiator? Followed directions and now my head gasket doesn't leak but my radiator is totally clogged. Rad was new.**
A: It’s a 32 ounce bottle. If you’re putting it in a car you should only use 10 ounces. I wonder if you didn’t use a whole bottle, perhaps?
I added a whole bottle to my Kenworth and my problem was solved. 
I had a Radiator seam leak in a plastic/aluminum radiator

**Q: is there a limit to size of leak?**
A: I had a small leak on the head gasket it sealed it fine I believe it would seal a larger leak, be sure to take your thermostat out and flush the cooling system at least four times follow the directions on the bottle.

**Q: how clean it**
A: I wish to know that. I suggest all headache should go to the manufacturer because she did make function test except it does 'block the leaking'. I believe she does not know how to prevent the block of the coolant level sensor; how to prevent the trigger of high temperature warning from the temperature sensor of the engine...etc.

**Q: My 01 Civic only took 1/2 of the mixture (1qt sealant + 3qt water), even after burping - it took no more. Is this OK?**
A: run it

## Customer Reviews

### ⭐⭐⭐⭐⭐ it worked
*by S***E on August 7, 2024*

used this to fix a hairline crack somewhere in the block or timing cover. so i have a 2010 jeep grand cherokee with a 5.7 hemi motor, bought it real cheap due to haveing a head gasket issue due to an overheat , im a tech for 40 years and know these hemi's well ,i did all the work myself , replaced both head gasket heads were sent out and resurfaced and i did a valve job , the motor fired right up and ran perfect when finished , however i noticed my coolant level was dropping slowley with know external leaks , after investigating i found coolant in my catch can so know i knew that it was getting into the crankcase, after i drained out about 8 0z of oil from the sump i saw a little bit of coolant in there but not to bad and not a lot . the coolant seemed to be entering the crankcase but more as a vapor if anything because most was in my catch can. there was a hairline crack somewhere . i decided to try this but was very skeptical . and low and behold it worked ! i couldn't believe it , no more coolant in my catch can or in the bottom of oil sump , i was amazed it actually worked , its been a year now with about 7k miles and still holding up! no coolant loss ,no heater core or radiator issues, i did put a new thermostat in it after about 100 miles running on it and found some hardened material around it but i wasn't worried about it after i installed a new one . i recommend this if you have a small leak due to a crack .

### ⭐⭐⭐⭐⭐ Works like a charm so long as you can follow the instructions.
*by P***H on April 2, 2015*

I have a suspicion that the bad reviews of this product are coming from people who are using it incorrectly. I had a blown head gasket (confirmed by repair shop when they replaced my timing belt, water pump, and thermostat) on a 1995 1.5L Honda Civic engine. The only reason I picked up a bottle of this sealant was because the mechanic recommended it after I told him that I couldn't afford a $500 dollar repair bill for replacing the head gasket. The mechanic told me that he'd used this stuff before and that it was pretty much the only head gasket sealant on the market that he'd ever seen work and told me that he would never recommend any other but this stuff actually works. So I ordered a bottle and gave it a try. The first thing I noticed was that the instructions clearly state that you should read the entire label before starting and that you should know exactly how much fluid your radiator and engine block hold and to use a specific amount based on the volume. It also clearly states that if your water pump or thermostat are not properly working that it will not work properly and could cause uneven distribution of the product. It states clearly on the label to use the proper amount and to add it very slowly into the properly diluted radiator fluid and not to add the product until the fluid level is high enough not to touch the fins on the inside of the radiator. After doing just that, letting the engine run and the coolant cycle and then topping it off, and then letting it idle for over 15 minutes with the heat on, I could already tell that the engine was running as smoothly as it did before the blown gasket. After several days of driving, it no longer overheats, no longer produces white smoke from the coolant leaking through the gasket into the engine, no long is leaking oil into the coolant and is no longer running rough. The stuff is very clumpy and can look worrying but when the proper amount (for me 1/3 a bottle) is added to properly mixed 50/50 fluid, it cycles through and smooths out. I plan on letting it stay in the engine until I get ready to flush the radiator out and get the rest off the product out but the bottle clearly states that you can leave it in without flushing and that it will not cause clogging or sludge. So far it has work perfectly and seems to have sealed the gasket completely but even if it does begin to leak slightly, it says that you can add more which I plan to do if it does, though so far it after 4 days of daily commuting for 36 miles, it has had no problems and works perfectly. I'd recommend it to anyone who can properly follow instructions but I would imagine that if you added it to the wrong coolant type or mixture or if you added way more than was intended that it would cause major problems with clogging up your system. Having a new water pump probably also helps, as I would imagine that if your water pump wasn't properly cycling the stuff that it would clog up in the system and prevent the sealant from reaching the leaking points and possibly clog up the radiator or heater coils. Use it as intended and it should turn out just fine.

### ⭐⭐⭐⭐ works fine
*by W***S on March 3, 2014*

my only reservation to giving 5 stars is that the directions were hidden under a back peel-off label like medicine bottles except without an obvious note that it was there, so I applied it according to directions remembered from the reviews on amazon but forgot to mix it first. It plugged the radiator but fixed the head gasket. overall I came out ahead but I'd like to seriously bitch about the hidden directions. A used radiator is relatively cheap but that part was unnecessary and a bother which is on the head of whoever designed the label.

## Frequently Bought Together

- K&W 401224 FiberLock Head Gasket & Block Repair - 32 Fl Oz
- K&W 401232 Permanent Head Gasket & Block Repair with Nanotechnology - 32 Fl Oz
- CRC K&W 401016 Block Seal Permanent Metallic™ Block & Radiator Seal - 16 Oz

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-03-21*