I replaced the accumulator ball and removed the old fluid and replaced with new. all was fine until i came home from work and went to brake for the driveway, brake light came on and very little brakes. i assumed a busted line. pulled in the garage. looked underneath and found no leak. i also had the fan run after i turn off the motor. i had to disconnect the battery to stop it.(another issue). after i reconnected the battery and started the car, i pressed the brake pedal and it got hard again and the light disappeared. drove a few miles, seems to be fine. i did hear the brake motor run and building pressure when i restarted the car. any thoughts of why loss of brakes?