Talk to a tax pro. (I would go a little higher up the food chain than one of the store front tax outfits.)
The chances are good that you and your brother or the estate was entitled to the value of the home on the date of death. Your capitol gains taxes would be measured only on any increase in the value of the house between death of your last living parent and when you sold the house. I also think the executor can choose an alternate valuation date that is six months after the date of death. Confirm with a tax pro. As executor, you may have needed to make that decision back then.
Given the relatively flat real estate market the past couple of years, the home probably sold for a loss relative it's date of death value, at least on paper. Moreover, in computing any possible capital gains taxes, you or the estate may be entitled to a credit for certain buyer paid closing costs. In other words, if you determine the house was worth $100,000 on date of death and you have certain eligible closing costs of $5,000, then these costs are added to the $100,000. If you (or the estate) sold the home for $103,000, technically, there is a loss of $2,000. You may be able to take this paper loss to reduce your individual taxes. However, there probably is something that you as executor may need to do so that you and your brother can claim the loss on your individual taxes, if applicable.
Ergo, the chances are good that neither of you really owe any taxes whatsoever. But, if your brother is reluctant to be involved, the possibility of some kind of tax break may "change his tune".