To determine what type of brake fluid you need, you should consult your vehicles owners manual or the master cylinder reservoir cap. The type of brake fluid required for your vehicle will depend on the make and model of your car. There are different types of brake fluid, including DOT 3, DOT 4, DOT 5, and DOT 5.1. DOT 3, DOT 4, and DOT 5.1 are glycol-based fluids that absorb water and are commonly used in modern vehicles. DOT 5 is a silicone-based fluid that does not absorb water and is typically used in classic cars and vehicles that need non-petroleum-based brake fluids.

It is important to use the correct type of brake fluid for your vehicle, as using the wrong type can cause damage to your braking system and compromise your safety. Brake fluid must pass testing for the ability to remain fluid at a low temperature and resist boiling at a high temperature. It must also be compatible with other brake fluids and parts of the braking system and effectively control the corrosion of your brake system.

In general, brake fluid flushes are recommended every 30,000 miles or two years. Its a good idea to have your brakes and brake fluid checked by a professional technician during every oil change. A mechanic can inspect the overall health of your brake system and determine if new brake fluid is needed.