What was found
WHILE ACFT WAS PASSING THRU 26000 FT THE NR 3 ENG BEGAN TO COMPRESSOR STALL. CREW PERFORMED APPROPRIATE PROCEDURES AND RETURNED TO DEPARTURE WHERE IT LANDED WITHOUT INCIDENT. POST FLIGHT INSP WAS PERFORMED. THE NR 3 ENG PRBC WAS REMOVED AND REPLACED. WHILE REPLACING THE PRBC IT WAS NOTED THAT THE BLEED CONTROL HIGH PRESSURE AIR SUPPLY TUBE WAS BROKEN AT THE B-NUT. LINE WAS REMOVED AND REPLACED, OPS AND LEAK CHECKS WERE GOOD. NO OTHER DEFECTS WERE NOTED. ACFT WAS RETURNED TO SERVICE.