Q: Why does my wheel cylinder keep breaking?

Without specifying exactly what keeps happening, it’s hard to tell exactly what problem you are having. The replacement of the wheel cylinder should be straight forward by removing the brake shoes on one side only. Remove and replace the wheel cylinder. Install the brake shoes and install the drum and adjusting the shoes till a slight drag on the drum is felt. Now go to the other side and do the same thing. Once all the brakes are installed and the drums are on then you can bleed the brakes starting with the right rear, left rear, right front, left front, then repeat till all air is out of your brakes. Under no circumstances should you push on the brakes with the rear drums off the vehicle. this will push the wheel cylinders out till they push out the pistons. If you still have issues then contact a mechanic, like one from YourMechanic.com, to come and help you properly replace your rear wheel cylinders.