Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.)
Hover over the image to zoom in
Share this:

Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.)

Part No. PLT11 Warranty Details  
Seal internal, external and coolant-to-oil leaks with Bar's Leaks Stop Leak Heavy-Duty Radiator Sealer. The pelletized formula works safely on plastic, aluminum and metal radiators. Product Features: Designed for use on plastic, aluminum and metal radiators, heater cores, blocks, heads, gaskets and freeze plugs, Compatible with conventional green (silicate-based) and red, orange or yellow (OAT) antifreeze, Patented Rhizex pellets dissolve quickly to seal internal, external and coolant-to-oil leaks, Lubricates water pump seals and prevents formation of rust and scale, Helps to prevent corrosion and control electrolysis, 1 bottle treats systems up to 4 gallons

Product Features:
  • Protects Engine Cooling Systems
  • Stops Current and Future Leaks
  • In hibits Rust & Corrosion
  • Lubricates Water Pump Seal
  • Helps Control Electrolysis
Back To Top
Antifreeze Type Compatibility:Yes
Boiling Point at 50/50 Mixture:>480 deg F
Contains Corrosion Inhibitors:No
Contains Ethylene Glycol:No
Contains Lubricant:No
Contains Stop Leak:Yes
Manufacturer Warranty Compatibility:Yes
Non-Toxic:Yes
Radiator Material Compatibility:All
Recommended Change Interval:12000 mi

REVIEW SNAPSHOT®

by PowerReviews
Bars LeakStop Leak Heavy-Duty Radiator Sealer (11 fl. oz.)
 
3.3

(based on 15 reviews)

Ratings Distribution

  • 5 Stars

     

    (7)

  • 4 Stars

     

    (1)

  • 3 Stars

     

    (2)

  • 2 Stars

     

    (0)

  • 1 Stars

     

    (5)

64%

of respondents would recommend this to a friend.

Pros

  • Easy to use (12)
  • Reliable (5)
  • Can withstand use (3)

Cons

No Cons

Best Uses

  • Home garage (7)
  • Upkeep (6)
  • Roadside repairs (5)
  • Automotive repair shop (3)
    • Reviewer Profile:
    • Casual driver (6), Auto enthusiast (5), Mechanic (5), Truck enthusiast (3)

Most Liked Positive Review

 

Used by new car manufactures for decades

Bars stop leak has been used in new cars for decades. It was put in every older Cadillac everytime a radiator was replaced by GM service centers nation wide due to their systems having...Read complete review

Bars stop leak has been used in new cars for decades. It was put in every older Cadillac everytime a radiator was replaced by GM service centers nation wide due to their systems having leaks. Mainly intake leaks on HT-4100 series. Its a great product and I have added it to hundreds of vehicles for over 35yrs without any issues.
I have used it on some really bad leaks that I though it would be a waste of money by adding it and ended up being simply amazed it worked on them. Not just that it stopped it fast as much as it stopped them for good. Really great product and just so glad Prestone didnt change it after buying Bars years ago.

VS

Most Liked Negative Review

 

bad stuff

dont use it,it will stop up your radiator and cause over heating and you will have to get another radiator!!!!!

dont use it,it will stop up your radiator and cause over heating and you will have to get another radiator!!!!!

Reviewed by 15 customers

Displaying reviews 1-10

Back to top

Previous | Next »

 
5.0

sealant

By 

from pensacola, fl

About Me Casual Driver

Verified Buyer
3 or more reviews submitted

Pros

  • Easy To Use

Cons

    Best Uses

    • Home Garage

    Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

    Good product.

    Comment on this reviewHelp Icon(earn points)

    (1 of 2 customers found this review helpful)

     
    5.0

    Great stuff,used as instructed,no leaks!

    By 

    from Villa Park IL

    About Me Auto Enthusiast, Casual Driver, Mechanic, Truck Enthusiast

    Pros

    • Can Withstand Use
    • Compact Design
    • Easy To Use
    • Reliable

    Cons

      Best Uses

      • Automotive Repair Shop
      • Home Garage
      • Roadside Repairs
      • Upkeep

      Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

      Used this on my 1997 ford f150 with radiatior & heater core leak. Flushed coolant as instructed by product. Added to upper radiator hose, didn't pre dissolve in water. Filled up with new coolant. Ran truck for 15 min, drove for 10 min and then ran for 30 more minutes. Leaks are now fixed! Thanks for making a great product bars!!

      Comment on this reviewHelp Icon(earn points)

      (1 of 3 customers found this review helpful)

       
      5.0

      Used by new car manufactures for decades

      By 

      from USA

      About Me Auto Enthusiast, Mechanic

      Verified Buyer
      3 or more reviews submitted

      Pros

      • Can Withstand Use
      • Easy To Use
      • Only One To Use
      • Reliable

      Cons

        Best Uses

        • Automotive Repair Shop
        • Conditions System
        • Prevents Future Repairs
        • Roadside Repairs
        • Upkeep

        Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

        Bars stop leak has been used in new cars for decades. It was put in every older Cadillac everytime a radiator was replaced by GM service centers nation wide due to their systems having leaks. Mainly intake leaks on HT-4100 series. Its a great product and I have added it to hundreds of vehicles for over 35yrs without any issues.
        I have used it on some really bad leaks that I though it would be a waste of money by adding it and ended up being simply amazed it worked on them. Not just that it stopped it fast as much as it stopped them for good. Really great product and just so glad Prestone didnt change it after buying Bars years ago.

        Comment on this reviewHelp Icon(earn points)

        (1 of 2 customers found this review helpful)

         
        5.0

        worked great Cadillac north star

        By 

        from folkston ga

        About Me Casual Driver

        Pros

        • Easy To Use

        Cons

          Best Uses

          • Upkeep

          Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

          Need pellets for north star 4.6 used this product an it worked great to replace the gm pellets for cooling systen

          Comment on this reviewHelp Icon(earn points)

          (2 of 3 customers found this review helpful)

           
          5.0

          Bar's stop leak

          By 

          from Westchester,Ohio

          About Me Auto Enthusiast, Truck Enthusiast

          Verified Buyer
          Level 1

          Pros

          • Easy To Use
          • Reliable
          • Saved Me 200

          Cons

            Best Uses

            • Automotive Repair Shop
            • Home Garage
            • Roadside Repairs

            Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

            I have a Ford F600 Dump truck. The power steering belt came off & trashed the radiator, so I thought. I checked prices on a new radiator. Up and more than $200. I thught I would try the Bar,s stpo leak, had great reviews. I had a few squirters on my radiator. 1 bottle & NO LEAKS.Saved me more than $200 BUCKS!!!!!!

            Comment on this reviewHelp Icon(earn points)

            (3 of 6 customers found this review helpful)

             
            5.0

            Good Stuff

            By 

            from Griffin, GA

            Verified Buyer
            3 or more reviews submitted

            Pros

            • Easy To Use
            • Reliable

            Cons

              Best Uses

              • Roadside Repairs
              • Upkeep

              Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

              Just follow the instructions folks. It's not a miracle worker but I once drove an Oldsmobile around for 5 years with cracked heads (not the gasket, the heads) and one bottle a year helped me to wait till I could fix it right. Steamy windows due to weepy heater core - very likely to put an end to that problem. Small hole in your radiator or radiator end caps - very likely to put an end to that too. In fact, if the mandrel in your water pump is a little leaky or some freeze plugs have pin hole and you need some time, I would bet this will help. Just be sure to follow the instructions.

              Comment on this reviewHelp Icon(earn points)

              (2 of 4 customers found this review helpful)

               
              1.0

              Didn't Help, Might've Made Leak Worse

              By 

              from Atlanta, GA

              About Me Casual Driver

              Verified Buyer
              Level 2

              Pros

              • Easy To Use

              Cons

              • Didn't work
              • May Worsen The Leak

              Best Uses

                Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

                I used it as directed, and within a few days noticed my coolant leaking on the ground, when I parked. I could see it dripping down, and kept having to put more coolant into the car, to maintain proper levels. When I took it to a garage, they showed me a hariline crack on the top of the radiator. I discovered that my mechanic had mentioned it to me months ago, but I forgot he did, and since I only had to add fluid now & then, didn't think it was a pressing issue. That's when I tried the Stop Leak, thinking it might stop up my slow leak. Well, as I said, if anything, it made it much worse. Now I have to get a new radiator...

                Comment on this reviewHelp Icon(earn points)

                (1 of 2 customers found this review helpful)

                 
                3.0

                Not a fix just for maintenance

                By 

                from N PLF NJ

                About Me Mechanic

                Verified Buyer
                Level 2

                Pros

                • Easy To Use

                Cons

                  Best Uses

                  • Upkeep

                  Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

                  easy to use just didnt fix 2 little pinholes had to drain rad and remove to have pro fix

                  Comment on this reviewHelp Icon(earn points)

                  (1 of 2 customers found this review helpful)

                   
                  5.0

                  I would buy again

                  By 

                  from manchester,n.j

                  About Me Casual Driver, Mechanic, Truck Enthusiast

                  Verified Buyer
                  3 or more reviews submitted

                  Pros

                  • Can Withstand Use
                  • Compact Design
                  • Easy To Use
                  • Reliable

                  Cons

                    Best Uses

                    • Home Garage
                    • Upkeep

                    Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

                    Tryed other products,they did not work as well as this brand

                    Comment on this reviewHelp Icon(earn points)

                    (5 of 10 customers found this review helpful)

                     
                    4.0

                    Stops most leaks it seems

                    By 

                    from Central Virginia

                    About Me Auto Enthusiast

                    Verified Buyer
                    Helpful Reviewer

                    Pros

                    • Easy To Use

                    Cons

                      Best Uses

                      • Home Garage

                      Comments about Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.):

                      First time I have used this product in years, and it still works. The pellets seem to melt and fill in any leaks in the radiator and heater coil. I had a leak in my heater coil and it has stopped, although the smell is still sometimes present when heat is cut on.
                      ***Don't know if it is related, but a heater hose bursted the day after I put this product in the vehicle's radiator, but it was an easy fix.***

                      Comment on this reviewHelp Icon(earn points)

                      Displaying reviews 1-10

                      Back to top

                      Previous | Next »

                      Do you have questions about this product?(earn points for answers!)

                       

                      Ask a question, get answers from real customers and in-house experts. For further assistance, please review your support options on our Contact Us page.

                      12 Questions | 12 Answers
                      Displaying questions 1-10Previous | Next »
                      • Q:

                        1995 ford Aerostar 4.0 I flushed the cooling system. what is the best product to use to seal any small leaks and prevent future ones
                        I have used bars leak for over 50 years and will with good results. my first use was on my 49 Plymouth. I would not consider using any other product
                        Asked on 9/7/2016 by Jim from Stone Mtn Ga

                        1 answer

                        • CUSTOMER CARE

                          A:

                          Hi Jim, glad to assist you! This Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.) (Part No. PLT11) will be a good choice to seal any small leaks and prevent future ones. The pelletized formula works safely on plastic, aluminum, metal radiators, heater cores, blocks, heads, gaskets and freeze plugs. Patented Rhizex pellets dissolve quickly to seal internal, external and coolant-to-oil leaks, lubricates water pump seals and prevents formation of rust and scale, help to prevent corrosion and control electrolysis, 1 bottle treats systems up to 4 gallons.

                          Answered on 9/8/2016 by Steve from AAP
                      • Q:

                        Can Bars Leak be added through the reservoir or must it be added directly to the cooling system ??
                        Asked on 8/2/2016 by T.J. from Roanoke, Va.

                        1 answer

                        • CUSTOMER CARE

                          A:

                          Hi T.J, glad to assist you! This Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.) (Part No. PLT11) is only designed to be added to the cooling system.

                          Answered on 8/3/2016 by Steve from AAP
                      • Q:

                        can I use this product on a 1999 Toyota Camry Le
                        Asked on 5/17/2016 by theresa from United States

                        1 answer

                        • CUSTOMER CARE

                          A:

                          Hi Theresa, glad to help you! Bar's Leaks Pelletized Radiator Heavy Duty Stop Leak is specially formulated to seal larger leaks better than other stop leak products. It works safely and effectively on plastic, aluminum and metal radiators, heater cores, gaskets and freeze plugs. It also has a water pump lube that lubricates water pump seals and inhibits the formation of rust and scale. Dosage: Use 1 bottle for 6, 8 and 10 cylinder gas or diesel engines. For 4 and 5 cylinder engines, use ½ of liquid and pellets. For more information, please copy and paste this technical data sheet link. URL - http://barsleaks.com/wp-content/uploads/2014/11/PLT11-Tech-Sheet.pdf

                          Answered on 5/18/2016 by Steve from AAP
                      • Q:

                        HEY SO I HAVE A 2005 CHEVY BLAZER AND MY RADIATOR IS LEAKING CAN I USE THIS TO SEAL THE LEAK AND WHERE MY BACK UP COOLANT GOES IS LEAKING TOO CAN IT BE USED IN THAT AREA AS WELL?
                        Asked on 4/22/2016 by brianna from tampa fl

                        1 answer

                        • CUSTOMER CARE

                          A:

                          Hi Brianna, glad to help you! Bar's Leaks Pelletized Radiator Heavy Duty Stop Leak is specially formulated to seal larger leaks better than other stop leak products. It works safely and effectively on plastic, aluminum and metal radiators, heater cores, gaskets and freeze plugs. It also has a water pump lube that lubricates water pump seals and inhibits the formation of rust and scale. Dosage: Use 1 bottle for 6, 8 and 10 cylinder gas or diesel engines. For 4 and 5 cylinder engines, use ½ of liquid and pellets. For more information, please copy and paste this technical data sheet link. URL - http://barsleaks.com/wp-content/uploads/2014/11/PLT11-Tech-Sheet.pdf

                          Answered on 4/26/2016 by Steve from AAP
                      • Q:

                        if radiator water capacity is 300 liter then how much QTY of stop leak required to fix a slight leak?
                        Asked on 1/5/2016 by Masoom from Kohat / Pakistan

                        1 answer

                        • CUSTOMER CARE

                          A:

                          Hi Masoom, I'm glad to assist you. It is recommended to use 1 bottle for 6, 8 and 10 cylinder gas or diesel engines. For 4 and 5 cylinder engines, use ½ of liquid and pellets.

                          Answered on 1/6/2016 by Solomon from AAP
                      • Q:

                        do i add this to radiator when it is hot or cold?
                        Asked on 11/22/2014 by csak from lorton, va

                        1 answer

                        • CUSTOMER CARE

                          A:

                          Hi CSAK, glad to assist you! Here is the direction to use this product. Cooling systems that are dirty or partially clogged should be flushed before usage. First, allow engine to cool so radiator cap can be safely removed and shake well to pour directly into radiator. Do not pack pellets in radiator. Pellets may be pre-dissolved if necessary by putting them in hot water. Note: If you don’t have access to radiator, remove top hose where it connects to top of radiator and install product in hose. Reattach hose and tighten clamp. Fill radiator and overflow tank to proper level, reinstall radiator cap and drive or idle engine for 15 to 30 minutes. Leave Bar’s Leaks in cooling system for preventative maintenance. Use once a year to help guard against future leaks. For more information please visit this link. URL - http://barsproducts.com/system/pdfs/64/original/PLT11%20Tech%20Sheet.pdf?1377268505

                          Answered on 11/24/2014 by Steve from AAP
                      • Q:

                        How far can I go with out it starting to leak again? Will it last for a 3- 3 1/2 drive?
                        Asked on 7/10/2013 by Missy from Milwaukee, Wi

                        1 answer

                        • CUSTOMER CARE

                          A:

                          The recommended change interval for the Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.) (Part No. PLT11) is 12000 miles. For any further assistance, please feel free to call us at: 1-877-238-2623 or visit the nearest Advance Auto Parts store and one of our Parts Pros will gladly assist you with any questions or concerns you may have.

                          Answered on 7/11/2013 by Steve from AAP
                      • Q:

                        Will this product clog up and/or otherwise harm the cooling system and/or cause the engine and/or transmission to overheat?
                        Asked on 6/11/2013 by Hank from Jacksonville, Fl

                        1 answer

                        • CUSTOMER CARE

                          A:

                          No, this Bars Leak Stop Leak Heavy-Duty Radiator Sealer (11 fl. oz.) -part# PLT11 will not harm the cooling system and cause the engine and transmission to overheat as it is to protect the Engine Cooling Systems. For any further assistance, please feel free to call us at: 1-877-238-2623 or visit the nearest Advance Auto Parts store and one of our Parts Pros will gladly assist you with any questions or concerns you may have.

                          Answered on 6/11/2013 by Vincent from AAP
                      • Q:

                        can i use this on a jimmy? it takes dexcool coolant
                        Asked on 8/30/2011 by sweetzz from Mi

                        1 answer

                        • CUSTOMER CARE

                          A:

                          Yes, you should be able to use this in your Jimmy.

                          Answered on 8/30/2011 by Steve from AAP
                      • Q:

                        I have a 48 Willis Jeep that the radiator is leaking along a seam were it is sealed togeather. It may be a copper radiator. Will this work
                        Asked on 8/25/2011 by Anonymous

                        1 answer

                        • CUSTOMER CARE

                          A:

                          It will work only on plastic, aluminum and metal radiators.

                          Answered on 8/25/2011 by DIY Daniel from AAP
                      Displaying questions 1-10Previous | Next »

                      Do you have a question about this product? 

                      Create or view your online garage

                      Check out the specials in our monthly flyer.

                       
                       
                      Disclaimer We strive to keep all information accurate and up-to-date; however, product availability, pricing, promotions and store hours are subject to change without notice. Please contact Customer Care if you have any questions or corrections.