What was found
(CAN) PART INSTALLED IN ACFT, WAS UNABLE TO BLEED BRAKE ON RT PILOT SIDE. WOULD PULL FLUID FROM RESERVOIR, & RETURN FLUID TO RESERVOIR THROUGH SAME LINE. INTERNAL BY PASS NOT FUNCTIONING PROPERLY. DISASSEMBLED ON BENCH, FOUND BY PASS STUCK & UNABLE TO MOVE. PARTS UNABLE TO SLIDE SMOOTHLY ON SHAFT, METAL SHAVINGS FOUND INSIDE. BACKUP RING FOUND TORN & BLACK SPECS FOUND INSIDE CYLINDER WITH SHAVINGS, NO O RINGS IN STOCK, UNABLE TO SERVICE REMOVED U/S CYLINDER AOG ISSUED FOR NEW MASTER CYLINDER.