Reload data from backend for model with findAll an RSVP.hash

I struggle a couple of days with ember data (emberfire adapter). It seems not to be possible to reload the data from the database ?

this is the model :

model: function() {
    console.log('In model');
    return Ember.RSVP.hash({
        customers: this.store.findAll('customer',{reload:true}),

This data is diplayed in a ember models-table ! After doing a update of some data i want to reload the model from the server ? But this seems not to be simple ???

1) reload:true (like above) seems not to be working (bug in ember data ??)

2) a action with .reload() seems only to work on record level not on collection level ?

How can i manage it to reload the data from the server ????