What was found
DURING A DAILY INSPECTION, A/C POWER WAS TURNED ON. THE ANTI-SKID BRAKE PUMP BEGAN TO RUN, BUT WOULD NOT SHUT OFF ONCE SYSTEM PRESSURE WAS MADE. TROUBLESHOOTING REVEALED A BAD IN-LINE PRESSURE SWITCH. SWITCH WAS INSTALLED 459.4 HOURS AGO. TAKING INTO CONSIDERATION THE ONLY TIME THE SWITCH FUNCTIONS IS BETWEEN 900 TO 1300 PSI, THE ACTUAL OPERATING TIME IS ACCUMULATED DURING GROUND OPERATION, WHICH IS MUCH LESS.