What was found
LEFT BLEED TRIP OFF ILLUMINATED. QRH ACCOMPLISHED. RESET SUCCESSFUL AT FL380. ACFT GROUNDED. ACCOMPLISHED WRENCH CHECK OF ALL VALVES. NO FAULTS FOUND, IAW AMM 36-00-00. REMOVED AND REPLACED PRE-COOLER CONTROL VALVE IAW AMM 36-12-12. REMOVED AND REPLACED HIGH STAGE VALVE. LEAK CHECKED GOOD IAW AMM 36-11-06. ALSO REMOVED AND REPLACED PRE-COOLER CONTROL VALVE SENSOR. LEAK CHECKED GOOD IAW AMM 36-12-03. RAN ENGINE AT IDLE, ALL LEAK AND OPS CHECKED GOOD. FOUND LOOSE SENSE LINE ON THE HIGH PRESSURE REGULATOR. SECURED SENSE LINE. LEAK AND OPS GOOD.