What was found
OUTBD BRAKE PRESS LO AMBER CAS: AFTER LANDING IN IAH WE HAD TO GET TOWED INTO THE RAMP FROM THE TAXIWAY. WE SHUT DOWN THE ENGINES OPENED THE DOOR AND GAVE THE LINEMAN THE GEAR PINS. I THEN PRESSED THE BRAKES TO RELEASE THE PARK BRAKE AND WE GOT AN AMBER OUTBOARD BRAKE PRESS LOW CAS MESSAGE. ENGINES WERE SHUT DOWN LESS THAN 3 MINUTES. FOUND OUTBD BRAKES ACCUMULATOR TO BE LOW. SERVICE ACCUM. TO PROPER LEVEL REF. CL350 MM 12-12-00. THEN COMPLETED BRAKE ACCUMULATOR FUNCTIONAL TEST OF THE BRAKES FOR PRESSURE RETENTION. ACCUMULATOR CHECKS GOOD REF. CL350 32-43-37-720-801.