What was found
(CAN) UPON ACFT SHUTDOWN, CAS MESSAGE, BRAKE ACCUMULATOR, DISPLAYED. BRAKE ACCUMULATOR PRESSURE WOULD NOT HOLD RENDERING PARK BRAKE INEFFECTIVE. ACFT HAD AN IDENTICAL PROBLEM 18 MONTHS EARLIER THAT WAS THE RESULT OF A FAILED HYD CHECK VALVE, PN L95H07-202 UPSTREAM OF BRAKE ACCUMULATOR. REFER TO MFG SERVICE ADVISORY 32-40-032-R01-A. NEW AND IMPROVED PN L95H07-204 CHECK VALVE WAS INSTALLED THAT SHOULD ELIMINATE THE POSSIBILITY OF A FAILURE OF THIS NATURE. NEW STYLE CHECK VALVE FAILED IN SIMILAR MANNER AS THE ORIGINAL WITH JUST OVER 700 OPERATING HOURS.