Three times over the last 6 months my brake pedal has gone to the floor then after I pump it a few times it stars working correctly again. Then it could be months before it happens again. Each time I have taken it for service and they find nothing wrong with the brake system, but naturally find other things that "need" fixed. Last time it happened I found a few articles about the ABS hydraulic control unit and mentioned that to the service tech. He said if that unit goes faulty your brake pedal always goes to the floor and does not come back like mine does. He said it was not the ABS hcu. From the youtube videos I have seen that is the case as well, the pedal is always low,
Any suggestions?
Thank you

 

A questionable brake master cylinder can do this.