What was found
LANDING GEAR WOULD NOT RETRACT ON T/O COMPLIED WITH QRH PROCEDURES COULD NOT RETRACT RETURNED TO EWR. PLACED FUSE BYPASS LEVER IN BYPASS POSITION, FOUND TRIM CYLINDER RELIEF VALVE LEAKING. REPLACED TRIM CYLINDER RELIEF VALVE IAW M/M 32-37-03-2, LEAK CHECK GOOD.