This is my first post so ever so here we go! I am trying to fix a Volvo ec25 with a strange hydraulic issue. When the hoe is cold everything works great as soon as it starts to warm up the engine labors when operating any function! when this happens the pump sort of binds up and bogs the engine down until you reach over and slap either joystick quickly. When it gets real hot the drive motors cause this to happen real bad to the point where any movement causes the pump to bear down on its self. Running aw46 oil just serviced with zero contaminants found in the tank or filter. Removed the main relief valve and found nothing wrong. The pump sounds great and has tons of power i do not think the pistons are in trouble! Also checked to make sure the Aux pedal is not stuck. 2,200 hours on the clock i have the repair manual and Volvo says there is a bulletin for sticking spool valves. Any help would be more than Appreciated!
Good day If a valve was to stick it would attempt to move a function, have you checked out the motor? Kind regards Uffex
The engine is fine its definitely an issue with the hydraulics maybe a problem with the ls regulator feedback loop or the bearings on the swash plate in the pump that control the plate angle?
Good day You can check for a false LS signal by "T" into the LS line with a gauge, if you get a false signal when warm the issue is at the main valve block area - normal LS signal could be pump but it would be a strange issue. Kind regards Uffex
Did anyone solve this problem? I have same problem on my ec30 year 2004. It did start when driveing. But now it do whit allmost any move i do. Change filters, chek the hyd.pymp. Change hyd.pump valves. Some how i feel its the hydraulic return sircuit problem???