John Deere 310A Cavitating and Bucket/Hoe raise part way

[Lurch]

Hello All,
It's been a while since I have been here.
Anyway my 310A gets used about 1-2 year. This time I check the Hyd Oil and looks frothy when I used it a couple weeks ago and was cavitating but usable.

I put about 2 gals of oil in and it looks way over full but frothy. When I ran it today it still cavitates but after I put the 2 gals of hyd oil in, the bucket and hoe raise slow and only about half way.

Any ideas what is going on?

It has always had a hairline crack in the trans and leaks oil over time and I collect it and have to replenish it.

 

[Roger in Iowa]

Frothy says air is being sucked in on the suction side of the pump. Don't know what
your system looks like but could be loose fitting, split or failed hose, cracked
steel line, and all could be evidenced by a slight oil leak.

 

[Lurch]

As it turned out, I went back out later, ran the booms up and down slowly for a while and it stopped most of the cavitating and then all worked fine.

 

[coonie minnie]

I had one of those that apparently had a leak in the suction line to the transmission pump that feeds the big pump. Keeping the transmission over full kept the leak submerged, and the issues would go away.