下午好 。!!!!
它也可能是方向拉链的图意接头或密封。 Always when the oil level is correct so that it does not take the pump air and it is working, you can be electric (it can have an electrical failure, fuse, pump feeding, connectors, etz) or mechanics, (giving mobility through a service strap, as for example, anternator, Air Air, Etz, Etz) The bomb (blades, which takes air by a joint)
if all that is correct you will have to go to your trusted workshop and replenish
I hope it has been有帮助。问候