Brake flush rule of thumb: Every 2 years. Who does that? Almost nobody; I know I don't but I also know I should. If I rented out vehicles, oh hell yes! But comparing oil changes to brake fluid flushes is apples to oranges. Oil is exposed to the combustion process, brake fluid is not. Brake fluid (as we all know) has a different job. I doubt there is 'detergents" in brake fluid. Engine oil contains detergents, (really just a polymer that tends to keep tiny solids in suspension so it doesn't settle out in the oil pan) so the filter can do a better job at trapping them. The trouble with brake fluid is that it absorbs water (hence the heavy duty gasket under to cap/lid) and water boils when it gets hot and brake fluid gets hot. Water doesn't lube the parts in a brake system either; it promotes corrosion, I'm sure we have all seen rust in a brake system. I sure have. The longer it sits the worse it gets. Theory: The reason it rusts more when it sits is because by routinely using the brakes the water is distributed throughout the brake system so it doesn't promote corrosion in ONE spot (where we can see it)but in much smaller spots all though the system. So, maybe we should take another look at this?