A downhole tool system includes a base tubular that includes a bore therethrough; a centralizer positioned to ride on the base tubular, the centralizer expandable to contact a wellbore wall and adjust a location of the downhole tool system relative to the wellbore wall based on a first fluid pressure supplied through the bore; and a liner top assembly positioned to ride on the base tubular, the liner top assembly including a wellbore liner and a pack-off element, the pack-off element expandable to at least partially seal a liner top of the wellbore liner to the wellbore wall based on a second fluid pressure supplied through the bore.