What was found
AFTER TAKE OFF NLG DID NOT RETRACT. MAINS RETRACTED NORMALLY. NLG GREEN & RED UNLOCK LIGHT. HEARD SURGING & MOVEMENT OF NLG EVERY 10 SECONDS OR SO AS THE NLG KEPT TRYING TO RETRACT. AT ONE POINT RECEIVED NO GREEN LIGHTS & ONLY RED UNLOCK LIGHT. LOWERED GEAR HANDLE RECEIVED AN AMBER CAS "HYD PUMP A FAIL" FLASHED ON & OFF. GEAR LOWERED NORMALLY & LOCKED. PERFORMED GEAR SWINGS, NOTICED AT LOW FLOW NLG WAS SQUEALING FROM AIR IN SYS. PERFORMED 10 CYCLES AT 2 GPM AT 3000 PSI EACH CYCLE GEAR GOT QUITER. PERFORMED 10 CYCLES AT 6 GPM AT 3000 PSI AND GEAR FUNCTIONED NORMAL WITH NO INDICATIONS.