Bobcat 751, Lost all hydraulic oil

[APenn]

I've used this skidsteer for a few years with no problems, then the first time I use the front auxiliary port and engage these ports, I lose all my hydraulic oil out the bottom of the skidsteer, to the point where I can't drive the unit. Lifting the cab, I can't see any obvious leaks under the cab. I had been planning on servicing and replacing all oil in the near future. How do I start troubleshooting? Add more oil whilst observing with the seat up? Can I just run the cheapest 10W30 to do this troubleshooting?

 

[Tazza]

You must have blown a line under the cab for the oil to run out like that.
There is no issue running that oil for testing, i run engine oil in mine without issues.

 

[Bswwood]

After filling with oil, raise cab with machine running and aux turned on, you should be able to run aux with seat bar up and machine running. Slowly engage aux with toggle switch and see where the leak is coming from.