Trek 7.3 FX Disc - Squeaky disc brakes
Recently purchased a used Trek 7.3FX disc (2009 or 2010 model I believe). Before I bought it, I had a test run and the brakes were squeaking very hard as I applied the brake. The owner decided to knock off another $50 for me to take it for a tune-up. I took the risk and decided to purchase it anyways, seeing it was a fairly good deal (I believe) at $350 CAD including pump and lock.
Question is, the squeaky noise, is that because the disc brakes need some oil (he hasn't ridden it in a couple years)? What should I apply to the disc brakes to fix the squeaking, or is it a bigger problem than that?