As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT BRAKE PEDAL SPONGY AND REQUIRES EXCESSIVE PEDAL TRAVEL. THE AIRCRAFT FAILED AN ALTERNATE BRAKE CHECK. LEFT SIDE. SUSPECT ALTERNATE/ AUX BRAKE FLUID RESERVOIR REQUIRES REFILLING. THE AIRCRAFT WAS GROUNDED. LEFT AND RIGHT BRAKE CONTROL MASTER CYLINDERS REPLACED IAW MM 32-43-12.