What was found
WHILE ACCOMPLISHING BLEED AIR CROSSOVER TEST FOR REPAIR CONFIRMATION OF LT ENGINE LOW DUCT PRESSURE, NOTED RT ENGINE DUCT PRESSURE DID NOT RISE ABOVE 15 PSI UNTIL 50% N1, ALL OTHER PARAMETERS NORMAL. SUSPECT NR 2 ENGINE HIGH STAGE REGULATOR FAILURE. ACFT GROUNDED. CONFIRMED HIGH STAGE REGULATOR FAILURE. CONTROL PRESSURE TO THE HIGH STAGE VALVE DOES NOT RISE ABOVE 7 PSI. HIGH STAGE VALVE CHECKED GOOD, FULL OPEN BY 5 PSI, IAW AMM 36-11-00-710-803. LEAK CHECKED IAW AMM 36-11-00. REPLACED THE HIGH STAGE REGULATOR IAW AMM 36-11-07. OPS CHECKED GOOD. ACCOMPLISHED BLEED AIR CROSSOVER TEST AGAIN IAW AMM 36-11-00, OPS CHECKED GOOD.