I have a 2013 Ford Edge Se with 180,000 miles. about a year ago the brake pedal started getting soft after having the front pads replaced by a shop. I took back to them 3 times and they would bled the system and it would be good for awhile this get soft again after awhile. Until the last time and they they just saids that's just how ABS brakes are which I knew was BS and decided not to go back to them ever. So I took it to another shop they said the master cylinder was bad and leaking vacuum into the booster . So I replaced the master cylinder and bled the system. Brake pedal was still soft and goes to the floor. Took it to another shop thinking it needed to be pressure bled and a scan tool to bleed the abs they said that Master cylinder was bad. SO I had them change that one and had them bleed the system this time. Still soft pedal goes to the floor and they didn't charge me for the work they did and told me the ABS pump was bad. Took it to a 3rd mechanic he told me that master cylinder was bad and pouring brake fluid out the back because the last shop used too much pressure and blew the seal out the back of the cylinder which is probably why they didn't charge me. He has been working on the car for 3 weeks now has bled the system atleast 20 times, changed the rear brake pads as they were very low on the inside ( which no other shop informed me of ) changed the master cylinder twice and cleaned out the original ABS pump and even replaced it with one from a junk yard as a new one is $900 from Ford. The pedal is still soft and goes to the floor. Every shop keeps saying it's not the Brake booster as that would cause me to have a hard pedal not a soft one. The current mechanic says he's getting good pressure from every caliper when he bleeds the system except the passenger rear which doesn't have the same amount of pressure as the others. I'm at my wits end with this issue on this car up to now it's been a very good car and this is the only issue it's ever had but nobody seems to be able to fix this issue. This issue has cost me almost $1,000 at this point and still not fixed. Please help this is my wife's daily driver and I need it to be safe for her.