I have a 1996 Infinity G20 which is a great car. The dealership service department where I bought the car recommends replacing the brake fluid every 12 thousand miles.
A semi-mechanic friend of mine says that I should do it when I have to replace the brakes. Is one of these choices the right way to go or is there something else that I should do?
Infinity recommends on the '96 G20 that the brake system be drained, refilled and bled every 30,000 miles with DOT-3 brake fluid, preferably Nissan Brand, of course.
The reason behind replacing the brake fluid is not only dirt and foreign particle accumulation, but the fact that water is also being retained by the fluid. The more H2O that is absorbed the more corrosion to internal parts of the system will occur, along with the lowering of the fluid's boiling point. The boiling point is a crucial characteristic that needs to be maintained. Brake systems are subject to extreme temperatures, and once the fluid boils it will lose its hydraulic capabilities and reduce braking potential drastically.
The dealer's recommendation of 12,000 miles is a little premature unless you're driving under extreme conditions -- towing lumber, back street drag racing, and stuff like that.
Otherwise stick with the 30,000 mile intervals, and if you're in need of other brake work on or about the same time it's a great idea to have it done simultaneously and maybe save yourself some time and money.