One of the rare times one of our customers had repeated failures, it was on an MTB with hydraulic brakes. I mean, he blew out the stock brakes, as in blew out the pistons on the caliper itself. It had mid-grade Avid hydraulics. I forget which ones. We upgraded them with XTR hydraulic discs and he blew those out in short order as well. He was always in for a brake bleed. Like every other week. We tried to please him and ate a lot of dollars, but it was clear that it was user error. I bought the same exact bike myself around that time and I did plenty of trail miles with ZERO brake issues. Some people just tear **** up.