Hydraulic pump

[Siteworx]

How do you know if you hydraulic pump is going out. I was running my bush hog and would hear a whining from time to time.

 

[Tazza]

The only real way is for a shop to test it, they will load it down and measure the flow.
The whine could be normal hydrostatic pump noise, if it's loosing power as it warms up, it could be the pump starting to wear, but i wouldn't jump to that conclusion just yet.