What was found
BWI - FLT 988 - UPON LIFTOFF, JUST AFTER GEAR RETRACTION, CAPTAIN RECEIVED INDICATION OF SYSTEM A HYDRAULIC LOSS. CREW ACCOMPLISHED QUICK REFERENCE HANDBOOK PROCEDURES AND SHUTDOWN BOTH SYSTEM A PUMPS WITHIN TWO MINUTES. FLIGHT DIVERTED TO BWI AND LANDED WITHOUT FURTHER INCIDENT. AIRCRAFT WAS TOWED TO THE GATE. NO EMERGENCY WAS DECLARED. MAINTENANCE TROUBLESHOT LEAK TO THE RIGHT MAIN LANDING GEAR TUBE ASSEMBLY WHICH WAS FOUND CRACKED. REMOVED AND REPLACED TUBE ASSEMBLY. REMOVED AND REPLACED NR 1 ENGINE DRIVEN HYDRAULIC PUMP (P/N 65075-06) AS PRECAUTIONARY AND BOTH SYSTEM A CASE DRAIN FILTERS PER MM. NO CONTAMINATION FOUND. SERVICED HYDRAULIC SYSTEM AND PINNED GEAR. CYCLED LANDING GEAR LEVER TO U