What was found
AFTER TAKEOFF, THE NR 1 BLEED HOT CAUTION ILLUMINATED. RAN CHECK LIST. NR 1 BLEED HOT CAUTION ILLUMINATED AGAIN AFTER ABOUT 45 SECONDS. RETURNED TO FIELD. LANDING UNEVENTFUL. REMOVED FROM SERVICE. INTERROGATED CDS, FOUND NO PRESENT FAULTS LISTED. PAST HISTORY OF LT SIDE SHOWS CODES 7001,4201,4108. REMOVED THE LT BLEED OVERTEMP SWITCH IAW AMM 36-11-16-000-801, 56563. INSTALLED A NEW BLEED OVERTEMP SWITCH IAW AMM 36-11-16-400-801. OPS TESTED THE BLEED AIR SYSTEM WAS GOOD. NR 1 BLEED HOT CAUTION DID NOT ILLUMINATE.