It's Han's default to deal with problems, particularly ones that have to do with emotion, by avoiding them. So. Josh might be thankful in the fact that his Corellian friend did listen, but ultimately dropped the subject. What could he really add to a conversation about shitty fathers? Or a conversation about any kind of father, really.

"Nah. It looks great, kid." He says as he hands over the new part. "Now's the easy part. New part goes on the way the old part came off. Then we get everything back together and who knows, maybe she'll even start for us."