What constitutes estate expenses?

My brother is questioning the way I spent money from the estate of our father. He says that because I am inheriting 2 pieces of real estate, he wants me to pay for all property taxes, insurance, and maintenance & repairs to the 2 properties for the past 5 years since my father passed away. Nothing other than necessary things were done, like fixing broken windows, re painting, as well as upgrading to title 5. He says I am "benefitting" from this work. I say it was all part of my duty as executor to keep the properties maintained. It has taken from 3/2006 until 11/2009 to get all the paperwork in order because of a missing request for tax lien releases form. Since 11/2009 he has refused to sign (as co executor)over the properties to me even though he already has inherited 1 house which he lives in, and the entire proceeds from another house that was sold. He is also due to inherit a large piece of land. My father was a NY resident, although these properties are in MA. I am very frustrated.