Fill it up, and put cardboard underneath the car looking for leaks. Youre losing fluid somewhere. Could be just a blown seal on the caliper, or a hole in a brake line.
RIP Ben "Jever" Doebele, we wont forget you
Please, call me Chadley
1997 328iS... HR coilovers, Brembo F40 calipers, camber plates, it needs a CUMMINS!!
1990-somethin Chevy K3500... Cummins, cab swap, 5 speed, and lots of motor work. 20 MPG, 40 PSI, 507 ft/lbs torque