Low brake fluid is one of the most common reasons for the parking brake light of a vehicle to stay on after the handle is released. The fluid reservoir is located under the hood, near the dash of the car. If it is low, owners should add more fluid immediately to prevent air in the brake lines, which makes it difficult to stop and requires bleeding the brake lines.
CarsDirect.com indicates that a misadjusted switch on the parking brake sometimes causes the problem. It recommends adjusting the switch so that the light goes off. These switches also stick. Jiggling the brake lever often causes the light to stop indicating a problem.
The light also illuminates to indicate uneven hydraulic pressure in the brake system. This uneven pressure causes one or more of the brakes to apply sooner than the rest. If the higher pressure affects one side of the car, it pulls in that direction when the driver applies the brakes suddenly.
When the warning light indicates a problem, the brakes need immediate attention. Operating a vehicle with malfunctioning brakes is dangerous and leads to accidents. If the emergency brake light stays lit for any reason, a mechanic should inspect the braking system and make the necessary repairs.