First check deaeration & loading pressure. Check for leaks at the hansen & diasafe connectors & the air separator. Those are some quick references from there follow the troubleshooting guide.
<tech2>
Posted
Check deareation and flow motor pressures also there brushes to start with
<shhhh>
Posted
Look at your check valves-even if recently replaced! If it appears to be bulging where the tabs hold it together, then replace and test again. I had on do this with only 70 days in the machine! Had me scratchin' da noggin'....