Bar's Leaks Rear Main Seal Repair, 16.9 oz

I gave this product a try and could not believe its results. I read some reviews and that convinced me to try it out on my V6 Cherokee. After a few days, the oil leaking on the rear seal start to disappear. it is a very small leak with no dripping on the floor. but the leak was very noticeable as it used to smell oil when driving the car. The smell is almost gone after a few days driving the car. not sure how long this will last... I will continue to add one on every oil change and hopefully it will keep the small leak under control.

Excellent results on a 1962 Ford tractor. Added entire contents to a badly leaking rear main and stopped completely after 10 minutes of operation. Perhaps it will digest all my old Seals but for now I am a happy customer.

Have used this before, works well, follow instructions on bottle. Took a while to get it .But price is great.

This product did exactly what it was designed to do in the 2002 Tahoe and a 1998 Toyota Avalon.I will be buying it again if I ever need it

Only 3 stars because it didn't stop the leak. Used this in my 2005 Toyota 4Runner & 2003 Honda CRV. My 4Runner has a rear main seal leak. I have used this in the last 3 oil changes. The leak has not stopped. I believe the leak has slowed down about 75%. In the CRV the Oil still leaks. I think it's a head gasket and valve cover gasket leaking. Once again it reduced the leak by about 75%.

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 goodI 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.

My 1990 Chevy Silverado with the 5.7 engine developed rear main seal leak. It was drip, drip, drip while engine was running.I changed engine oil, put the stop leak and drove about a 100 miles round trip. The drip did not stop. I drove the truck the rest of the week with an average of fifty miles a day. Still drips. I am going to take it to the garage to have seal replaced. Mechanic tells me it might still leak after replacing the seal. I just won't park the truck in my driveway.

Works