Some flat bar hydraulic disc brake fettling for me.
Both the levers on the rear brakes of my two bikes have to be 'pumped up' before every ride.
My theory is the longer hose run compared to the front gives more chance for air to get in.
I didn't fancy a full bleed, but decided to check the fluid reservoir level.
A simple operation on the Tektro Auriga brake, a bit more complicated on Shimano XT due to an extra plate and screw inside the reservoir above the diaphragm.
Both fluid levels were low, the Auriga was close to empty.
The brakes take mineral oil, which my Three-in-One copy brand bottle says it is, so that's what I used.
I did some 'burping' as well, although didn't see much in terms of air bubbles.
The levers now bite further out, so that's an improvement, and I did the job this morning so hopefully I won't have to pump the levers after the bikes have not been ridden for a few days.