I have been driving 18 wheelers the past few years, after Driving Charter Bus for Decades now. I was transferring from Truck to Truck and asked the Fleet manager about a bucket of tools he had taken out of one of his Trucks. In that bucket was a truck size bottle of your Power Steering Stop Leak. He informed me of the cost of the seal replacement and poured in a small portion of this oil of yours in the fluid reservoir. The leak stopped cold turkey! I dumped some in my 1983 Chevy Van power steering fluid reservoir, and ...WaLa! The seal is holding now. I am so THANKFILLED for your SUPER Products! I'm gonna go get some more for the 1978 Ford Van Engine...Too Now! Thank you so much for your OUTSTANDING oil products!