slime in JD hydraulic system

[agmantoo]

My neighbor stores his 3 John Deere tractors outside. Two of these tractors have slime with a greenish tint in the JD brand (hy-gard) hydraulic oil. This problem surfaced when he had the lift on his sod drill fail to work as it should. I am aware of diesel fuel growing algae and I know there are treatments for this. My searching for how to treat the hydraulic oil did not result in anything of consequence. I did read that changing the hydraulic oil usually results in the problem reappearing within 3 months. Does anyone know of a means to rid/cleanse the system of the bacteria/algae to prevent it regrowing in new hydraulic oil? TIA

 

[john250]

I'd treat the problem by draining the system, changing the filters. Depending on your risk acceptance level. I'd run the sytem briefly with diesel fuel for a flush. Then, change the filters again and fill with good quality hyd oil.
Very expensive, but price a hyd pump.