Excavator hydraulic pump help ?

racerboy832 · Jul 11, 2021

One thing I just noticed was on the reservoir if I pick the boom up all the way it draws a vacuum on the reservoir. It’s only a slight vacuum as is barely moves it off the zero mark. If I’m using most other functions it seems to slightly pressure the tank. Is this normal?

oldnslo · Jul 11, 2021

Were you extending one or more cylinders when raising the boom? If yes you would be drawing more oil out of reservoir than being returned so possibly would see slight vacuum.

which pump failed, one with case drain hose connected to that end or opposite end?

racerboy832 · Jul 11, 2021

The side with the case drain hose failed. The drain is at the bottom side of the case. The machine was parked. I fired it up and was at low rpm. Moved it about 5 feet and it went bang. I never expected it and there was no sign of any problem. It probably had 25 hours on the pump. Fresh filters and oil.