Since some pumps like the one in the video only turn in one direction so if the machine you are using does not turn that direction you have to change the direction of the pump for it to work....so that's how you change the direction
Sir this is big and very use full and very use full video for me.. by seing this video i have changed the direction of 3 nos hydraulick pump wich was clock waise and i was waned anti clock.. Thanks a lot sir
