If you choose to undertake maintenance on your own Beta RR 400 then it is usually a good plan to have a Workshop Manual for a guide in case that you need to know how you can strip off a certain component including Brake Pads and fit it again safely.
Beta RR 400 Workshop Manuals will give you targeted diagnostic details for the vehicle so if something is broken it will help you figure out what the problem is and how to resolve it. You can then assess if you can do this on your own or if the job is too big you could make a reservation for your RR 400 in with a suitable garage.
Beta RR 400 manual