Hp2 tandem pump

Dusty,

I noticed that the service pages refer to a purging procedure, but don't specify what that purging procedure is.

Here is the procedure for the HP2 Tandem pump that seems to work for most.

1. Fill the HP2 pump with an approved hydraulic fluid (HT-1000 or similar approved fluid) to the normal cold level as indicated on the expansion tank.
2. Jack up the back tires just off the floor 3 inches  (please be safe during this operation) 
3. Start the machine engine and slowing increase the engine speed to a mid-throttle position.
4. Slowly rotate the rear tires forward then back to natural then reverse until both tires are rotating at the same speed. Stop engine remove jack stands and proceed to item number 5.
5. Drive the machine for 2-3 mins in forward and reverse to purge air out of the system. (you can also raise the back end of the vehicle off the ground and place on jack stands, then move sticks through full forward and full reverse)
6. Shut the engine off and re-check the fluid.
7. Add fluid as necessary to the appropriate level
8. Pump is ready for use.

https://www.parker.com/portal/site/PARKER/menuitem.98bf0856fd643a238c23b35b8320d1ca/?vgnextoid=894fb34395d2b210VgnVCM10000032a71dacRCRD&vgnextfmt=EN&citype=Division&from=division&divisionName=Pump+%26+Motor+Division&divid=688058