---
product_id: 3673728
title: "Rear Main Seal Repair, 16.9 oz"
brand: "bar's leaks"
price: "A$30"
currency: AUD
in_stock: true
reviews_count: 13
category: "Bar's Leaks"
url: https://www.desertcart.com.au/products/3673728-rear-main-seal-repair-16-9-oz
store_origin: AU
region: Australia
---

# Easy add-in at oil change Stops leaks in 100 miles/2 days 16.9 oz precision dose Rear Main Seal Repair, 16.9 oz

**Brand:** bar's leaks
**Price:** A$30
**Availability:** ✅ In Stock

## Summary

> 🛠️ Fix leaks before they fix your wallet!

## Quick Answers

- **What is this?** Rear Main Seal Repair, 16.9 oz by bar's leaks
- **How much does it cost?** A$30 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.au](https://www.desertcart.com.au/products/3673728-rear-main-seal-repair-16-9-oz)

## Best For

- bar's leaks enthusiasts

## Why This Product

- Trusted bar's leaks brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **DIY Friendly:** Simply add to crankcase at oil change—no mechanic needed
- • **Fast-Acting Formula:** Most leaks stop within 100 miles or 2 days of driving
- • **Cost-Saving Leak Control:** Avoid expensive repairs and keep your ride road-ready
- • **Seal Like New, Drive Like New:** Restores dried, hardened seals for a leak-free engine
- • **Universal Engine Compatibility:** Works with gasoline, diesel, synthetic & high mileage oils

## Overview

Bar’s Leaks Rear Main Seal Repair (16.9 oz) is a trusted, easy-to-use additive designed to restore and swell worn rear main seals and stop oil leaks quickly—typically within 100 miles or 2 days. Compatible with all gasoline and diesel engines using conventional, synthetic, or high mileage oils, it offers a cost-effective alternative to costly seal replacements. Simply add the bottle to your engine crankcase at oil changes to maintain a leak-free engine and extend vehicle life.

## Description

Have you noticed oil leaking from your car lately? Many car owners fear the puddle they see forming under their vehicles, and many worry about the time and cost to make it go away. That leak might be due to worn or dried seals. There’s no need to worry or spend your money on a costly repair bill, however. Our Bar’s Leaks Concentrated Rear Main Seal Repair quickly and safely restores those seals so you can get back on the road. Bar’s Leaks is the leader that specializes in chemical solutions for rear main seal leaks and other automotive issues. Our products are effective and affordable. And they’re easy to use, too. If you know how to pop the hood on your car, you can install our rear oil seal solution. We design our products for ease of use, because a good solution isn’t very helpful to everyday drivers if they can’t use it. At Bar’s Leaks, we do everything we can to get you back on the road in good condition just as quickly as possible, by offering rear main seal leak products and much more. Most rear main seal leaks are caused by a combination of normal wear in the crankshaft and seal combined with the drying, hardening and shrinking of the main seal. Bar’s Leaks Concentrated Rear Main Seal Repair restores the seal to like-new condition, and also contains additives to stop leaks in severely worn seals and crankshafts. Not to mention, it works with ALL gasoline and diesel engines using conventional, high mileage and synthetic oil. We’ve gone to great lengths to ensure that our rear oil seal solution is working for you in all possible ways. You can count on us for a rear main seal leak that takes care of your problems and helps prevent future leaking. You can trust that our products are the fastest, safest way to get your show back on the road — we’ve been proving that since 1947.

Review: Read this if you are considering buying this product for an oil leak! - I'll start by saying this product goes against everything I believe or have been taught about internal combustion engines, the two most prevailing thoughts before ordering this were: #1: Only oil goes in the crankcase, nothing else #2: Snake oil does not work, especially for a long term solution, fix the real problem instead of throwing money and additives at the problem that ultimately may do more harm than good I have a small block ford engine that has a notorious rear main seal leak, drips engine oil right at the transmission bell housing. Started small and got worse. This is a well documented problem, and the transmission must be pulled to replace the seal. I have heard many stories of people who have replaced the seal, only to have the brand new one leak too, people have tried crankshaft sleeves to make the fit tighter, and with mixed results. I did not want to go down this road unless I had no other option. I did a little research on this product, and the reviews are mixed. I have not heard any horror stories worse than "it didn't help and I wasted my money on this product", and from what I understand it works completely differently than the "leak stop" additives you would use for a head gasket, coolant leak, air conditioning system leak, or tire leak. All the latter leak stop additives are adhesive products which are glues and materials designed to fill cracks/voids and cure on contact with air. This product works differently. This product is not an adhesive of any kind and does not leave any residue. It is basically a solvent that attacks rubber and causes it to swell. This makes the seals fit a little tighter if the only problem is a seal is a little old or dried out. If the seal is cracked, deformed, or a synthetic material that the active ingredient in this product doesn't react with (its designed for rubber, not corks, silicones, etc), this product will most likely not help. I dumped this in the oil reservoir. It was already a little low from the leak, so the excess oil in the crankcase was not an issue. Ran the engine for about 30 mins and no change, still same dripping while running. I drove the vehicle every day approx 30 miles. After a week, the leak was barely noticable, just the bottom of the transmission housing felt a little oily, but no puddle/stains in the driveway. After 2-3 weeks, the leak was gone. And I mean gone, not a drop. I was impressed how well this worked on this problem and thought it fixed it permanently. Then about 4000mi later, I did an oil change. For the first few hundred miles after that, no leaks, then after about 1k miles, I noticed the leak started to return. I immediately picked up another bottle of this stuff and dumped it in, about 1 week later, the leak was gone. I now don't even mess around anymore and just add a bottle of this stuff to every oil change, and it is under control, its a small price to pay (even for life of vehicle) to not have to deal with the rear main seal. For me, this product makes a night and day difference, I have been using it for approx 30k miles, but depending on the root cause of your leak, your mileage may vary.
Review: Save me money and my truck - I just wanted to share a quick note about this product I used it about a year ago and since then really saved me a lot of trouble (and money!). My old truck, a trusty 2004 model, had developed quite an oil leak, losing about 1 to 1.5 quarts every single month. I was seriously considering getting rid of it because the thought of paying for expensive mechanic repairs just wasn't worth it for a vehicle of that age. It felt like a losing battle. But then I tried this product, and honestly, it's been a game-changer! It's been a full year since I started using it, and my truck is still running strong. I genuinely don't notice any oil loss anymore, which is fantastic. It does take some time to notices the product stars working but at the end of couple weeks you may start seeing that stars working. I've been adding it every other oil change. I'm not sure if that's overkill, but I'm just so thrilled to still have my truck and avoid those costly repairs. It's fantastic to have it back on the road without constantly worrying about the oil levels. Just wanted to pass along my positive experience!

## Features

- Seals timing cover, cam seal, rear main and other hard to stop oil leaks
- Add to engine oil
- Specifically designed to seal rear main leaks, but also works better than a conventional stop leak on all other leaks
- Add entire bottle of Rear Main Seal Repair to engine crankcase (where you add oil) at or between oil changes. Do not overfill. Most leaks will stop within 100 miles or 2 days of driving

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00754T6TK |
| Best Sellers Rank | #4,598 in Automotive ( See Top 100 in Automotive ) #20 in Fuel Additives |
| Brand | Bar's Leaks |
| Customer Reviews | 4.2 4.2 out of 5 stars (2,833) |
| Date First Available | February 3, 2012 |
| Global Trade Identification Number | 00046087010402 |
| Is Discontinued By Manufacturer | No |
| Item Form | Liquid |
| Item Weight | 1.1 pounds |
| Item model number | 1040 |
| Liquid Volume | 16.9 Fluid Ounces |
| Manufacturer | Bar's Leaks |
| Manufacturer Part Number | 1040 |
| Model | 1040 |
| Number of Items | 1 |
| Package Information | Bottle |
| Product Dimensions | 1.9 x 3.4 x 7.7 inches |
| Recommended Uses For Product | Fleet and plant maintenance. |
| Specific Uses For Product | Fleet and plant maintenance. |
| UPC | 046087010402 |
| Unit Count | 16.9 Ounce |

## Product Details

- **Brand:** Bar's Leaks
- **Item Weight:** 1.1 Pounds
- **Liquid Volume:** 16.9 Fluid Ounces
- **Package Information:** Bottle
- **Recommended Uses For Product:** Fleet and plant maintenance.

## Images

![Rear Main Seal Repair, 16.9 oz - Image 1](https://m.media-amazon.com/images/I/71BWlf2ZPcL.jpg)

## Available Options

This product comes in different **Size** options.

## Questions & Answers

**Q: Is this safe for diesels, specifically the Duramax 6.6L?**
A: Yes..... According to Bars Product, this is compatible with all engines and engine oils.

**Q: Can you use this with synthetic oils**
A: Yes, I have used it with synthetic oil with no issues.

**Q: What it does with my other gasket that has not have a leak?**
A: If I'm understanding your question correctly.... you would like to know what effect this has on gaskets that are not leaking?    The answer is nothing.....  Thank you  Eric

**Q: Is this safe to use with other gas additives such as seafoam, lucas?**
A: Yes there is no problem. This gets poured into your oil crankcase not into your gasoline. Seafoam usually gets poured into your gas tank to clean injectors and cylinder walls sometimes you can put it in the crankcase just about 4 oz to clean junk this does not stop any leaks usually done 100 or 200 mi before an oil change. Lucas has many products some that are injector cleaners that go into the fuel tank some that are oil stabilizers or stop leaks or friction additives that go into your oil crankcase you can have Lucas oil additive/stop leak and bars leak in your oil crankcase they don't interfere with one another

## Customer Reviews

### ⭐⭐⭐⭐⭐ Read this if you are considering buying this product for an oil leak!
*by T***E on April 27, 2014*

I'll start by saying this product goes against everything I believe or have been taught about internal combustion engines, the two most prevailing thoughts before ordering this were: #1: Only oil goes in the crankcase, nothing else #2: Snake oil does not work, especially for a long term solution, fix the real problem instead of throwing money and additives at the problem that ultimately may do more harm than good I have a small block ford engine that has a notorious rear main seal leak, drips engine oil right at the transmission bell housing. Started small and got worse. This is a well documented problem, and the transmission must be pulled to replace the seal. I have heard many stories of people who have replaced the seal, only to have the brand new one leak too, people have tried crankshaft sleeves to make the fit tighter, and with mixed results. I did not want to go down this road unless I had no other option. I did a little research on this product, and the reviews are mixed. I have not heard any horror stories worse than "it didn't help and I wasted my money on this product", and from what I understand it works completely differently than the "leak stop" additives you would use for a head gasket, coolant leak, air conditioning system leak, or tire leak. All the latter leak stop additives are adhesive products which are glues and materials designed to fill cracks/voids and cure on contact with air. This product works differently. This product is not an adhesive of any kind and does not leave any residue. It is basically a solvent that attacks rubber and causes it to swell. This makes the seals fit a little tighter if the only problem is a seal is a little old or dried out. If the seal is cracked, deformed, or a synthetic material that the active ingredient in this product doesn't react with (its designed for rubber, not corks, silicones, etc), this product will most likely not help. I dumped this in the oil reservoir. It was already a little low from the leak, so the excess oil in the crankcase was not an issue. Ran the engine for about 30 mins and no change, still same dripping while running. I drove the vehicle every day approx 30 miles. After a week, the leak was barely noticable, just the bottom of the transmission housing felt a little oily, but no puddle/stains in the driveway. After 2-3 weeks, the leak was gone. And I mean gone, not a drop. I was impressed how well this worked on this problem and thought it fixed it permanently. Then about 4000mi later, I did an oil change. For the first few hundred miles after that, no leaks, then after about 1k miles, I noticed the leak started to return. I immediately picked up another bottle of this stuff and dumped it in, about 1 week later, the leak was gone. I now don't even mess around anymore and just add a bottle of this stuff to every oil change, and it is under control, its a small price to pay (even for life of vehicle) to not have to deal with the rear main seal. For me, this product makes a night and day difference, I have been using it for approx 30k miles, but depending on the root cause of your leak, your mileage may vary.

### ⭐⭐⭐⭐⭐ Save me money and my truck
*by H***A on January 7, 2026*

I just wanted to share a quick note about this product I used it about a year ago and since then really saved me a lot of trouble (and money!). My old truck, a trusty 2004 model, had developed quite an oil leak, losing about 1 to 1.5 quarts every single month. I was seriously considering getting rid of it because the thought of paying for expensive mechanic repairs just wasn't worth it for a vehicle of that age. It felt like a losing battle. But then I tried this product, and honestly, it's been a game-changer! It's been a full year since I started using it, and my truck is still running strong. I genuinely don't notice any oil loss anymore, which is fantastic. It does take some time to notices the product stars working but at the end of couple weeks you may start seeing that stars working. I've been adding it every other oil change. I'm not sure if that's overkill, but I'm just so thrilled to still have my truck and avoid those costly repairs. It's fantastic to have it back on the road without constantly worrying about the oil levels. Just wanted to pass along my positive experience!

### ⭐⭐⭐⭐ Good product, seems to do the job pretty well
*by L***R on November 22, 2025*

Seems to work good, not perfect but definitely slowed down the leak quite a bit. I was getting a lot of drips from the rear main before, but now it's almost stopped, but not completely. I get a few drops here and there is all. Nothing major. So I'd say this project does it's job pretty good.

## Frequently Bought Together

- Bar's Leaks Rear Main Seal Repair, 16.9 oz
- Bar's Leaks OS-1 Oil Seal Engine Oil Burning and Leak Repair, 16.9 oz.
- Bar's Leaks 1420 Transmission Stop Leak - 11 oz. , Grey

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*Product available on Desertcart Australia*
*Store origin: AU*
*Last updated: 2026-02-05*