1010c hydraulics

[EdK]

I'm working on replacing some of the hydraulic lines it has a two lever valve one for the blade and one for what ever attachment would be used in the rear of the tractor. It has another lever on the same side with a 1" hose, one end comes from the outlet of the two lever valve and the other goes to the hydraulic oil tank. It appears to have been added and was not stock, can anyone tell me what it's purpose might be? Thank you Ed

[NNAATZ]

sounds like someone had added aux to run a single acting cylinder at one point in time