What was found
BLEED 1 LEAK YELLOW CAS ILLUMINATED - BLEED 1 LEAK AMBER CAS MESSAGE ILLUMINATED IN CRUISE FLIGHT AT 13,000 FEET. THE BLEED 1 AND 2 SWITCHES AND XBLEED KNOB WERE SELECTED OFF IN THE APPROPRIATE SEQUENCE AS DIRECTED BY THE QRH PROCEDURE. THE BLEED 1 LEAK CAS MESSAGE EXTINGUISHED MOMENTARILY TWICE AND THEN REMAINED ILLUMINATED FOR THE DURATION OF THE FLIGHT. A PRECAUTIONARY SHUTDOWN OF THE NUMBER ONE ENGINE WAS CONDUCTED AS DIRECTED BY THE QRH. **SUPPLEMENTAL INFORMATION - REMOVED & REPLACED DEFECTIVE AMS CONTROLLER IAW MM 36-21-01. OPS CHK GOOD.