lx 865 turbo hydraulic fluid change

[technician01]

Hi all, first time caller, long time listener! I'm doing a job for a friend on his skid-steer and I'm looking for some advice. LX 865 Turbo has moisture in the hydraulic fluid. 1. What is the proper way to drain the system? 2. Is there any thing I should change in the process( filters, lines, ect...)? 3. I've been using hydraulic fluid from Tractor Supply Company (TSC), it seems to work with all the other machines I have. Is this the right fluid for this system? Some other thread mentioned 10w30? Thank you for any help you can give me! Happy wrenching!