It is listed on the top of the master cylinder fill cap. More than likely DOT3.
it is an indicator. You need to check your brake fluid or your bulb.
D O T ( 3 ) brake fluid
Usually the cap of the reservoir will till you what kind of fluid, probably brake fluid, and how much to put in. Or if you look on the side of the reservoir there is a line for max fluid level.
You need to completely flush the system of all contaminated brake fluid. As this is a very serious and possibly dangerous situation I recommend you take this car to a professional and have the system completely flushed and refilled with fresh fluid.
Brake fluid does not need to be changed as oil is but constantly needs to be replenished.
Adjustment need to be backed off by the brake pedal!
After having problems with seizing wheel cylinders and other brake problems due to moisture in the hydroscopic brake fluid, I started flush clean fluid through the brake systems of my vehicles every 2 years... Have not had a single corrosion (or any brake problem for that matter) since...
DOT ( 3 ) brake fluid
DOT ( 3 ) brake fluid
Check the brake fluid level in the Master Cylinder. If it is low add DOT3 brake fluid to the full mark. If it was really low, the brakes need bleeding. This car is 13 years old and more than likely needs new brake pads if you have not replaced them. Have the pads replaced, rotors turned, and brake fluid changed.
If you are driving and need to brake, but find your brake pedal is getting closer and closer to the floorboard, you need the check your fluid. Eventually your brakes will not have enough fluid to create the pressure needed to apply the brake pads properly and you risk accidents.
You need to have the brake fluid changed immediately. Washer fluid will damage all of the seals in the brake system