I drive a 2013 Prius with 75,000 miles. Hearing some weird noises - please see video above for reference. Hissing while hitting the brakes, and Loud humming noise happening every 10-15 seconds when car is on, and for about 3 minutes after turning the car off. What could this be? Thank you!
Could be a bad brake accumulator. What level is the brake fluid level at? When was the last time brake fluid was changed?
The sound you recorded is the pump used to pressurize the brake fluid. If the pump turns on too frequently without stepping on the brake pedal, then you have a problem (usually an internal brake fluid leak in the brake actuator). Eventually, warning light will appear on the dash, and then you have a very expensive repair to fix the problem. Do you have any warning lights on the dash.
