I have a Puma 400 b it is only about 2 years old and just last week it kept giving a 2161 lubrication oil pressure down alarm . I called the doosan dealer in my area that we have come repair our machine when they go down and they said to rule out the pressure switch 1st so I did , I changed the pressure switch out and it still kept giving the alarm 2161. The pump has a gauge on it and when working properly it goes into the green and that is about 15 on the gauge ,when I get the alarm it only goes to 8 maybe 10 no where close to the green . Im thinking it could be a leak so I plug the line going out of the pump to the machine just to check the pump and it is not going up to the working pressure . Does anyone have any ideas