Change a sortedModel in ember

i have a sorted ember Model. Now i will this Model change and load new Data in. The Model has e.g. Userdata and the User clicked to 'load more' and new Data coming in this model. Badly the sortedModel has no the new data.

Has anyone any idea how this works?

He my sortedModel: sortedModel: Ember.computed.sort('model', 'sortBy')

And this is the data changing: this.get('model').pushObjects(records.content);