datapump

Hi I'm trying to export a full database with the system ID.
I have completed the following:

grant all on directory (directoryname) to system;

grant sysdba to system;

grant dba to system;

grant exp_full_database to system;

grant imp_full_database to system;

I know that is overkill just to export the database but I keep getting the error:

ora-31631:  privileges are required
ora-39161:  full database jobs require privileges

What could I possibly be missing to fully export the database.

Thanks
Ed