Voith B7TL GN04UDW on route 12 - Arriva 6407

Just an average sounding Voith B7TL. It has absolutely no power - we encounter a hill at 5:50 and quickly lose all speed.
This bus was serving route 12 from Tenterden to Maidstone.
Operator: Arriva Southern Counties
Fleetnumber: 6407
Registration: GN04UDW
Chassis: Volvo B7TL
Body: Alexander (Transbus) ALX400
Gearbox: Voith 4-speed