What's the proper way to use the jake brake

[Nilao]

As far as the high delay and mountain grades, you should already be in the gear you plan on going down the grade before you start down that grade. Miss that shift and you might not get it back in.

I read somewhere that the engine fan has a max revolutions of 2400 before it would explode. I'd imagine a fan like mine with 10 years of use would probably fail at a lower RPM.