atp automotiveAT-205 Re-Seal Stops Leaks, 8 Ounce Bottle

I can’t say enough good things about stop leak. My high-mileage car had a persistent oil leak coming from the engine, and I was looking at a pricey repair job. After some research, I decided to give this product a try as a temporary fix—and it worked better than I expected.I followed the instructions and poured it directly into the engine oil. Within just a couple of days, the leak slowed down dramatically, and by the end of the week, it had virtually stopped. I’ve now driven over 1,000 miles without a single drop on the driveway!What impressed me most is that it didn’t just mask the problem—it actually reconditioned the seals and helped reduce engine noise too. It’s a great solution if you're dealing with an aging engine and want to avoid an immediate, expensive trip to the mechanic.For the price and ease of use,it is absolutely worth it. Just make sure to use it exactly as directed and give it a little time to work. Highly recommended for minor to moderate engine oil leaks!

This is by far the most effective product at eliminating small leaks caused by hardened rubber seals. I tested it by adding it to a Mini with an oil filter housing leak to see if it would reduce the leak until i can get around to replacing the seals. The leak slowed after 90 minutes of driving (observed the following day) and within 3 days of short trips the leak completely stopped. I had tried high mileage oil and a few other products over the last 6 months but none were fully effective. I will look to update the review after the next oil change to see if the results remain once there is no AT205 in the oil.

Saw a couple of drops of oil under our 2012 RAV 4 and after one look under the car it was clear there is a rear main seal replacement in the cars future. $20 seal part but likely $1k to get the transmission removed to get to the seal. One bottle of this product 100% stopped the leak after one day of driving. The rear main seal repair still in our future but for now, can defer that fix and safely drive the car with no oil drips below.

Scotty Kilmer said AT-205 is watery and harmless because it’s a polymer. I’d never heard of a watery polymer. ATP calls it a plasticizer. A plasticizer is a solvent used to make a polymer more rubbery by loosening the bonds between molecules. This one seems to be diethylene glycol monoethyl ether.ATP says it won’t harm internal components. The website says it’s compatible with conventional and synthetic oils, ATF, gear oil, power steering fluids, and hydraulic oil. It has a 3-minute video, which for 5 seconds presents a chart of recommended amounts with three columns of seven figures each. Do they really expect you to digest that in 5 seconds?For those 5 seconds there are two lines of print below the chart. If you pause the video, they are grayed out and covered with ads. I had to replay that segment several times to be sure I understood. They say, “Recommended use is approximate due to blending properties with oil. No risk if slightly over treated.”Contrary to their assurances, this implies a risk. It seems as if ATP did not intend for the viewer to see the warning.The video devoted a minute to showing the representative open a hood, pour in a bottle of AT-205, and close the hood. An Amazon customer reported that after he did so, the concentrated solvent in the oil pan caused the paint to come loose and clog the screen on his oil pump. It’s not a new product, but the video didn’t recommend running the engine to mix the solvent. Buyer beware!My 35-year-old car occasionally smoked on startup. Probably the valve seals were worn or shrunken. Deposits from oil additives damaged spark plugs and O2 sensors. AT-205 would be a lot cheaper than having the seals replaced, but I was afraid AT-205 could expand seals more than necessary, and that could accelerate wear.For 4 quarts, ATP recommends 6oz, or 180ml. The oil would have about 4.7% solvent. I decided to try 100ml (about 2.7%) and add the rest if necessary. I used a polypropylene measuring cylinder. It measures precisely, pours as neatly as using a funnel, and rinses better than glass. I ran a short errand to mix it and ran another short errand the next day. Then I cleaned the grime below the valve cover gasket, which leaked.Months have passed. The gasket has not leaked, and I haven’t seen or smelled any oil smoke.My riding mower was 25 years old. An unseen oil leak caused chaff to accumulate on the cooling fins, hidden under the housing. That interfered with the flow of cooling air. It often smoked on startup. I didn't know if leaky rubber seals caused either problem.I added 25ml of AT-205, about 1% of the oil in the crankcase. I mowed a few minutes to mix it. The next day, I cleaned off the oil and grime. in the months since then, the engine has stayed clean, and it hasn't smoked on startup.The next time I have a leaky machine, I’ll start with 0.5% to minimize risk. I can always add more.Update: Scotty was right about using AT-205 to preserve plastic parts. My positive battery terminal protector uses a "living plastic" hinge. It had stiffened so that it wouldn't stay down. A couple of applications of AT-205 improved it. My big concern was the duct from the MAF meter to the throttle. It had become brittle over the years. It looked impossible to fabricate a new one with all those hose fittings. I've applied AT-205 three times. A little goes a long way. I put a teaspoon or so in a cup and apply it with a cotton ball. I also wipe it on pneumatic hoses. Plastic absorbs it slowly, so I check after a couple of days. Skin absorbs it readily, but research has shown it's harmless (pharmacologically inert).Another update: The manufacturer of my mower engine recommends oil changes according to engine hours and doesn't mention time intervals. I waited two years. During that time, the oil continued to feel and smell okay.Two weeks after the oil change, I got a lot of oil smoke on startup. I had assumed that the solvent not immediately absorbed by the rubber had evaporated from the old oil long ago. Apparently it had stayed in the oil, continually refreshing the old seals. Because I'd used it conservatively, I had some on hand to supplement the new oil.

I was skeptical at first because most leak stop products don't really work but this worked for me with my transmission leak. However, this product has to stay in whatever fluid your having a leak with. If you are using it on an oil leak for example, whenever you change the oil the leak will probably return until you put this product back in. So, it's not a permanent fix, but it does work.

Received my Amazon order for ATP Automotive AT-205 Re-Seal today and found the product box saturated and the bottle coated with the product. The shipping packaging was undamaged and seemed adequate.I took the bottle out of its product box, wiped the bottle down and inspected the foil seal under the cap. The seal was intact. I noticed my hand had fresh seal on it and the bottle again had seal on the outside of it again. Further inspection showed the molded seam on the bottle was weeping the product. I immediately took photos showing the bottle and its leaking seam. I haven't opened the bottle seal so I don't know how much of the product has leaked out.The bottle manufacturing quality appears deficient.UPDATE: I was contacted the next day after emailing the company about faulty container manufacturing, and Dave stated they would send a new bottle of product to replace that lost from leaking. They are a stand up, customer-oriented company and I would do business with them again.Update 2: Replacement bottle received as promise.

Leaked inside packaging!

This worked great for a while on my 2008 BMW convertible top hydraulic seals until one of them finally gave out. If they are really bad, this may not work. However, for the price compared to the $2600 the dealer wants to replace them, it is certainly worth a try.