First crack happens when the line hits a sudden load point, so keep the line straight, no tight bends, and make sure the material is rated for the pressure you’ll see. Keep the fluid free of air, check the seals, and torque the fittings to spec—over‑tightening can cause a pop, under‑tightening lets air in. Use a proper line‑guiding block if you can, and run a pressure test before you drop the wheel. That way the hydraulic system stays in the sweet spot, and you avoid a line failure that’d make you want to throw the whole setup into the trash.