Bleed your brakes. If the fluid is over 2 years old then drain it and replace with fresh new fluid. make sure you bleed the system of all the air, you will need a friend to help with this. Bleed the banjo bolts on the master cylinder and the rear caliper also. Then pump the brakes and bleed the caliper last.Long pedal to mechanical stop and quite bad response. Not able to lock on tarmac.
Tried to top up brake reservoir same fault.
Aren't these brake autoadjusting?
pads are approx 1/2 way done.