I have a Magura, brake set, but its their HS 33 Rim Brake for V brake post Frames 11 years back I replaced the Hoses, for longer,
After that all I did was replace brake pads .
'Olives' are what they call the sealing ring that grips the hose as you tighten the fittings , that is what can leak, you buy new olives,
and have to cut the hose shorter to get the old ones off..
Most shops only see hydraulic disc brake and predominantly Mountain bike.
Magura's rim brakes are a bit different , a Closed System, no expansion tank needed, like disc brakes
because applying the brakes does not heat the fluid,
so once the air bubbles are out , they don't need regular maintenance bleeding..
.....