Hydraulic Power Unit - Oil Fill

Applies to machines built from: 
June, 1997

Lathe - Hydraulic Power Unit - Oil Fill

This procedure tells you how to fill the oil in the HPU on all lathes. Most machines have a HPU oil gauge. ST-20/25 machines made in November 2015 and after have a dipstick.

Check the oil level at least (1) time a year. The oil level must show full.

Notify your HFO if you have any of these conditions:

  • There is coolant mixed in the oil. You can see the coolant on the dipstick, or through the oil gauge.
  • A "Low Oil Level" message shows on the display and you are on schedule for your maintenance.


The machine must be cold to fill the HPU with oil.

Tools Required

Mobil DTE 24

Step 1

Remove the HPU oil cap.

Use a funnel [1] and put the Mobil DTE 24 oil [2] into the HPU.

[A] Look at the HPU oil gauge [3]. Make sure the oil is filled to the top of the HPU oil gauge [3].

[B] Remove and examine the dipstick [4]. Make sure the HPU is full of oil. The HPU is full if the oil reaches the mark on the dipstick [4].

Install the HPU oil cap.

Be aware: Many service and repair procedures should be done only by authorized personnel. The service technicians at your Haas Factory Outlet (HFO) have the training, experience, and are certified to do these tasks safely and correctly. You should not do machine repair or service procedures unless you are qualified and knowledgeable about the processes.

Danger: Some service procedures can be dangerous or life-threatening. DO NOT attempt a procedure that you do not completely understand. Contact your Haas Factory Outlet (HFO) and schedule a service technician visit if you have any doubts about doing a procedure.