Switch Servo Fluid at KIA Sportage

Hi, I drove again with my father’s KIA Sportage (Bj.:1995, DOHC engine with 85hp?!) and had to find out that the power steering is no longer working. If you try to steer it, then it is very difficult… and now and then the steering wheel twitches something, as if it were working again. Furthermore, it seems to me that the sound of the servo pump is no longer heard. Well, then I have seen if a fuse is defective somewhere. All in all. Then ha b i once opened the container with the servo fluid I checked if there is anything right there anyway. Conclusion: the liquid is there… only it is bad luck-black ;-)… as far as I know it should actually be red or? Can you release the servo fluid yourself or do I have to put it in the workshop? Is there an exhaust screw? How is it best to do this? And which servo fluid do I need for this? Is there anything else special to consider? What would a new e Servo pump cost? Thanks for your help. mfg Schoash