Hey all, I’ve had this 2002 Tahoe LS for almost 2 years. I did the brakes (rotors/pads/fluid) when I first got it in May 2016. Nothing fancy. October 2017, I was driving with my family and the brake pedal went to the floor on the highway. No pressure whatsoever. It was late & I was about 70 miles from home. Well, we managed to get home safely. I took it to a local Firestone auto care the next morning. They told me I had multiple leaks in the system. Ended up replacing multiple brake lines & 2 calipers. Everything was good after that. Until I lost my brakes again in January (luckily, by myself this time). Took it back to them. They said something they repaired didn’t hold up, so they fixed it free of charge ( as they should). Everything was good. Till about an hour ago. Same thing all over again. My question is this. Is there a component they should be checking that could be the root cause of these failures? On the previous trips to the shop I was told the master cylinder was good, but is there something else? ABS pump maybe?