As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BLEED FAMV ENGINE 4 CAME ON AT LVL OFF AT FL 330. FOUND B-NUT LEAKING AT FAN AIR VALVE MUSCLE AIR CONNECTION. REPLACED MUSCLE AIR LINE AND TEMP SENSE LINE. BACKED OFF B-NUT AND SAW METALLIC PARTICLES. STEM FITTING LOOKED OK, LOOSENED ADJ LINE STAND OFFS. HAND STARTED B-NUT, HALF WAY DOWN STARTED TO BIND. REPLACED MUSCLE AIR LINE AND TEMP SENSE LINE.