Transmission Stop Leak Concentrate (1420)

Transmission Stop Leak Concentrate


  7 Reviews

Stops and seals transmission fluid leaks. This product is specially designed to stop seal and gasket leaks caused by normal transmission wear and age. It even works with ALL domestics and imports, as well as all automatic and manual transmission fluids. Proven by years on the market and over 100K units sold nationally. Bar’s Leaks is the leader in automotive aftermarket repair solutions, with products being used in consumer, commercial, OEM and military applications for over 70 years.


Add entire bottle of Bar’s Leaks Transmission Stop Leak to transmission to restore fluid level. Do not overfill. Leaks usually stop in 200 miles or 3 days of driving. If leak continues, second application may be required. If leak persists after second application, mechanical damage may be severe and professional attention may be necessary.

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This product is specially designed to stop seal and gasket leaks caused by normal transmission wear and age. It even works with ALL domestics and imports, as well as all automatic and manual transmission fluids. We’ve got you covered. All Bar’s Leaks products — our transmission stop leak and more — are easy to use. That’s because we want everyday driver to be able to use our solutions to stop leaking transmission fluid — even if they don’t know much about what’s going on under the hood.

All you have to do now is follow our easy installation process. While many worry about applying products under the hoods of their cars, our transmission stop leak solution couldn’t be easier to use. In under an hour, your overworked transmission will get the help it deserves so you can get back on the road and back to your life. You won’t find a more effective or affordable solution for transmission fluid leaks than Bar’s Leaks.


When you need effective chemical repair solutions that help avoid a pricy trip to the mechanic, Bar’s Leaks is here to help. We’ve been developing and offering problem solving products for transmission fluid, engine oil, power steering, head gaskets, cooling systems and much more for nearly 70 years. Located just an hour outside of Detroit, our headquarters employs top-flight chemical engineers who are all pushing toward a common goal — delivering the most affordable, effective products to stop leaking transmission fluid and other automotive issues.

We’ve served tens of millions of customers through our decades of service. Why do they keep coming back? You can find plenty of products on the market that claim to stop transmission fluid leaks. But many of these products are ineffective, and some even make your issue worse. At Bar’s Leaks, we offer real solutions when you need a transmission stop leak. Our team is always innovating to improve our existing products and develop new products as auto manufacturers introduce new developments (such as DSG/twin clutch transmissions). There’s a reason why we’re the best-known transmission stop leak brand in the industry. Trust Bar’s Leaks and discover just how effective our products are at stopping your transmission fluid leak.

Get your leaking transmission fluid solution today.

Customer Reviews

  7 Reviews
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 7 reviews
 by Gary L.
Fixed my trans leak

My name is Gary, I used your Transmission Stop Leak, and it took care of my front seal from leaking, and I also used the Jack Oil with Stop Leak and it's a jackin’ well.

 by James Hashem M.

I just paid over $400.00 HUNDRED DOLLARS for a thermostat housing repair...and just the week later my radiator let go. Asking another 400.00. No way I was paying for the radiator. I remember when I was a young guy, I had used something like that but this stuff is the best...I thank God for Bar's putting great people in Customer Service, with a good sense of humor and too help make people happy again. Thank you very much for your services.

 by Matthew
Very useful product

Im an owner of the 2001 Honda Civic LX 5-Speed and came to find the transmission fluid was leaking but by drips. So i thought okay until payday comes Bar's Leak will help until i can have it checked out. I drove for 3 days and realised the fluid no longer drips from under my vehicle. This product is very useful until you can get your vehicle to a mechanic. Highly recommended.

 by Shiy S.
Leaking transfer case

I towed my 4x4 Grand Cherokee about 500 miles with the steering wheel locked before I realized what I'd done! Oh snap! The transfer case ALMOST separated from the differential but miraculously I was able to save it just by gently shoving it back in and forcing the gears to hit. From that point on the tranny started to slip. It would go from 1st gear straight into a hard 3rd and I thought I'd toasted the tranny for sure. I just added my 2nd bottle of Bars Leaks and while it's not completely factory-grade repaired it has gotten me another solid 600 miles that I didn't expect and I'm not quitting til she's up on blocks! I live by this product.

 by B. M. - Cartersville

I want to thank you for making products that work. My transmission had a front pump seal that leaked out 4 quarts of fluid in about 300 feet. So I went to the auto store to get some fluid and see if I could find some stop leak. I won’t put just anything in my car either. While looking around I found one that said Bar's I thought if anything will work this will. So I put it in and about 3.5 quarts of fluid and drove the car 30 some miles back home. I will replace the seal. But I did not need a wrecker. Thank you.

 by Anyonio - Salinas, CA

This additive really works! While I was changing my transmission fluid I discovered a leak coming from the side of the transmission where the shift leveler connects to the tranny. It would leak a few drops of atf every morning, the mechanic quoted me $600 just to change the stupid little seal. I decided to try this product but I only poured less than half since the leak wasn't too bad and after 3 days of driving the leak complety stopped, thanks for saving me $$$ great product!!

 by F. Walker - Grand Blanc, MI

About one year ago, I purchased a bottle of Bar's Leaks power steering stop leak concentrate and it solved my power steering leak problem.

About two months ago, I was experienced a loss of prime on my automatic transmission when I stopped at traffic lights (Buick Terraza). I decided it was either internal leaks or scored pump. I put in a bottle of your Bar's Leaks transmission stop leak concentrate and my problems have disappeared. Apparently some internal seals were softened up enough to again do their job.. Your technology is good for more than power steering! You probably already know this but I just wanted to thank you!

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