Good question. At the brake fluid resovoir
If you mean where to add brake fluid, it would be in the brake master cylinder, usually located on the driver's side, near the firewall. You should be able to see a round plastic reservoir with a gray cap ... unscrew to add brake fluid.
ADD BRAKE FLUID
You open the hood, find the brake fluid reservoir, take the cap off and add DOT 3 brake fluid up to the full level.
You can add brake fluid inside the brake fluid reservoir. The reservoir is located on the driver's side under the micro-filter panel.
Locate the brake fluid reservoir, and pour brake fluid in until it's at the appropriate level.
Should be next to the brake fluid cup. DJ FLIP Housepartykings.com
The 1994 Ford Probe has a brake fluid reservoir that should be mounted on the drivers side firewall. Remove the cap on top to add fluid.
Brake fluid reservoir is located on the firewall next to the steering column. Remove cover top of master cylinder to add brake fluid.
The red brake light indicates that the parking brake is on or that the brake fluid is low. Be sure to add the specified brake fluid if you add fluid. Also make sure that you don't allow any dirt to get into the brake fluid and don't overfill the brake fluid either.
The low brake fluid signal on a Chevy Cavalier indicates that the brake fluid level is below the recommended level. It is important to add brake fluid immediately to prevent brake system failure, which can result in loss of braking power. Check for leaks in the brake system when topping up the brake fluid.
Add brake fluid