* Corrosion: Age, rust, and exposure to road salt weaken brake lines over time.
* Physical damage: Impact from rocks, road debris, or accidents can damage lines.
* Manufacturing defects: Though rare, a faulty brake line can fail.
* Excessive vibration: While unlikely to directly cause a rupture, *severe* and *prolonged* vibration could potentially weaken a line over a long period.
Resurfacing rotors and replacing pads are routine maintenance procedures that shouldn't affect brake lines. However, if a mechanic is working on the brake system, they should inspect the lines for any signs of corrosion or damage. A competent mechanic will always check brake lines as part of a brake job. If there is pre-existing damage, the repair of that damage might inadvertently cause further problems, but again, that's not directly related to rotor resurfacing and pad replacement.
In short, the two procedures are unrelated, but a thorough inspection of the entire brake system is always a good idea during any brake work.
