Hi Scotty! I think your videos are really useful. Love the dedication. I want to ask you something about a german car, Europe made, Opel(Buick) Astra G 2002 160,000km. I know they are different in US but maybe you can help. Break fluid is leaking somewhere but I can't find it. Checked the calpers, the break shoes in the back(cylinders), all bone dry. Hoses good too. All that's left is brake booster and master cylinder. Where is the fluid? It's still leaking very slowly. How do I fix this? Thank you.

master, fluid leaks inside the booster where you can't see

Thanks, should I also replace the booster? What happens when it's full of fluid?