My comment is a year late, but for the sake of others who may come along later... Reg 1.263(a)-3(k)(1)(iv) requires capitalization when the expenditure "Returns the unit of property to its ordinarily efficient operating condition if the property has deteriorated to a state of disrepair and is no longer functional for its intended use."  Going from a state of not functioning to functioning means it is capitalizable.  I thing 3(k)(1)(vi) would also likely require it to be capitalized.