Call model not work

I use acl for restriction over hook:

class ACL {
private $perms;
private $role_field;
private $CI;
public function __construct() {
$this->CI =&get_instance();
if (!isset($this->CI->session))
{ # Sessions are not loaded
$this->CI->load->library('session');
}
if (!isset($this->CI->router))
{ # Router is not loaded
$this->CI->load->library('router');
}
if (!isset($this->CI->url))
{ # Router is not loaded
$this->CI->load->helper('url');
}
$this->CI->load->model('permisos_model');
//$this->CI->load->model('recursos_model'); <- work if enable here

if($this->CI->session->userdata('rolID')){
$this->role_field = $this->CI->session->userdata('rolID');
} else
$this->role_field = 0;
$hola = $this->CI->permisos_model->getAllow();
foreach ($hola->result_array() as $key => $value) {
$this->perms[$value['rolID']][$value['controller']][$value['metod']] = ($value['status'] == 1) ? TRUE : FALSE;
}
}

But it is no longer necessary to state in the controller constructor, what problems or what would help or hurt this situation?