What was found
HMO - FLT 104 - GDL - DURING DESCENT, INDICATION STARTED TO CLIMB AND LOW FLOW LIGHT TURNED ON WITH PRESURIZATION VALVE CLOSED, ENGINE ACCELERATED TO 1.5 EPR AND A/C INDICATED PRESSURE OF 12 PSI. SYSTEM WAS CHECKED FOR LEAKAGES AND BOTH CONTROLLERS PRESSURE TRANSFER RELAY WERE TESTED, ALL CORRECT. LEFT REGULATOR PRESSURE VALVE AND FLOW CONTROL VALVE WERE REPLACED IAW MM 21-31-1/2 AND MM 21-32-3, ALL CORRECT. (M)