743 foamy hydro oil

[richfrazier]

hi .. I have a bobcat 743b with a foaming hydro oil problem. My fear was it was a drive motor problem but the Drive seems to be ok and chain case isnt filling up with oil. So i narrowed it down to that its only foaming up when the lift cylinders are moved up and down. It foams up right away and gets choppy. All other functions seem fine. The machine is tight with no leaks. It should be leaking oil if air is getting in right? Any help or ideas would be great..Thanx, Rich

 

[richfrazier]

i probably should ad that ive drained and replaced the hydro oil with no change

 

[Tazza]

i probably should ad that ive drained and replaced the hydro oil with no change

With the cab up, looking at the hydraulic pump, is there a square block on it with 3 hoses going into the left side?
I'm thinking the foaming is pump caevtation... If it's the older style that has a hidden filter, the filter gets plugged causing a lower pressure and you get foaming of oil.
Hopefully it's that easy.