There is a demag crane in the yard with the problem. Crane works fine in the morning, all the operations are just fine. As the temperature rises outside and in the noon the super structure functions falter. The hoist down operation works fine but it doesn't go up. Boom up/down operation doesn't work either. The general operation of the outriggers and the suspensions is sluggish too.. I'm suspecting it could be any of the pump or the hydraulic fan.. (ATTACHED)
Has it just started doing this, or came on gradually? What is your outside air temperature when it malfunctions? What grade oil does the machine have in it? If you have access to a temperature gun, check the inlet and outlet of the hydraulic cooler?