At the start of A New Hope Luke is working on Uncle Owen's moisture farm.
What was his job on the farm?
The night after Owen purchases C3PO and R2D2 Luke makes the claim that he thinks the droids will work out and that he would no longer be needed to help on the farm. Although Luke might've been stretching the truth to support his argument so he could leave a season earlier, no one calls out Luke for making wild claims about the droids being able to do his work. Considering what C3PO and R2D2 are physically capable of that Luke would also be able to do, Luke's job duties would seem to fall into the range of driving vehicles (collecting moisture perhaps) and small equipment repairs.
Are his job duties ever detailed in EU or by anyone that worked on the films?