You can skip reading all this and just go buy some Wilwood EXP 600 Racing Brake Fluid. The only thing better is from Castrol and it is VERY expensive and is beyond our needs. Wilwood also makes 570 Racing Brake Fluid which costs half as much as EXP but has a slightly lower boiling point.
Also, NEVER use a silicone (DOT 5) brake fluid. It does not absorb water, so when water drops get into your system, and they will, they will boil at 210° causing vapor lock which will either lock-up your brakes or cause brake failure. DOT 5 also has a tendency to foam easily giving you a squishy pedal.
Brake fluid has two boiling points. The Dry boiling point is the temperature where the fluid boils when it is fresh out of the sealed bottle. Wilwood EXP has a 626° dry boiling point. Most standard DOT3 fluid has a dry boiling point of 400°. Heavy Duty DOT3 or 4 usually has a 470° dry boiling point. The higher this boiling point, the more use your brakes can stand before they will start to fade or fail.
The second boiling point for brake fluid is its' wet boiling point. This is the temperature where the fluid boils when it is saturated with water. Most DOT 3 fluid has a wet boiling point of 278° and Wilwood EXP has a wet boiling point of 417°. One of the jobs of brake fluid is to absorb water from the brake system. For lack of a more scientific explanation, let's just say that by absorbing the water, the brake fluid gives up some of its' dry boiling point peak temp, in order to keep the water in the system from boiling.
Boiling is bad. Provided your master cylinder, calipers, and slave cylinders are in good working order, if you come in from a run and your front brakes are so locked-up that you can't turn the wheels with your hands, then you are probably boiling your fluid and either bleeding the brakes will be necessary, or a complete change of brake fluid will be necessary. You should bleed your brakes about every two weeks.
I'll explain how to do that later.
