One of the best penetrating oils I have ever used is ordinary hydraulic brake fluid
Don't know about that product, but a study I read about a year ago concluded that the best penetrating oil to use is simply a mix of kerosene and automatic transmission fluid. If that doesn't work then an old fashioned "blue torch" will.
tried the new wd-40 product ( santa gave it to me!), and im quite impressed, tried to remove a lu last night, and it would not budge without fear of twisting bolts off. tried again today after giving them a spray last night, they came out easily.
What new WD product?
as labeled: wd -40 specialist rust release penetrant spray. ( with "blue torch" technology!! lol) it did free up bolts /screws that felt like they were going to twist off. actually , most screws in the lu turned by hand with a screwdriver, no vicegrips on the shank.