Brake Fluid

Brake fluid provides the transfer of hydraulic pressure to the wheels.

Types of Brake Fluid. The most common type of brake fluid is DOT 3, but DOT 4, DOT 5, and DOT 5.1 are also available. Clean brake fluid is clear in color (except DOT 5, which is often dyed purple). Always refer to your manufacturer’s recommendations because brake system damage can occur with the incorrect type. Warning: Use extreme caution when handling. Brake fluid is harmful to your eyes and if spilled on a vehicle’s finish, it will strip paint.

Checking Brake Fluid. The brake master cylinder that houses the fluid is usually mounted on the driver’s side firewall in the engine compartment. Most vehicles today have a plastic translucent reservoir with “MIN” and “MAX” marks. Some fluid level drop may be normal. As the brake pads wear the level will fall as more fluid fills the brake caliper pistons or wheel cylinders.

Adding Brake Fluid. To add brake fluid, park on a level surface, turn the engine off, clean around the cap and reservoir, remove the cap, and add as necessary. When reinstalling the cap, make sure that the rubber gasket seats properly.