Hi all, just popping to gain some knowledge. Got a Suburban with gremlins in it. Been looking all over for the answers and can't find. In short, all four brakes apply themselves at the same time....randomly. Have changed hydroboost, master cylinder, calipers, discs, pads, multiple bleeds, even tried pulling the ABS fuse. Usually get a service stability notification around the time it happens. Have to either let it sit for the brakes to unlock or I have to crack the lines at the master cylinder. Took it to a mechanic as well and they said it was the hydroboost. Well, obviously it wasn't since I changed it once in addition to their changing it. So I'm stuck. Just did it again pulling an empty 3-horse trailer going UP hill. Brakes gradually applied to where I had to floor it to maintain 20mph. Pulled over and all four wheels were smoking.