Power Steering - minimum amount of oil required

[kent]

I have a Zetor 6045, and am in Wales, UK.

For what reason does the power steering oil reservoir hold so much oil? The User Handbook says to use 4.4 litres. The power steering hydraulic cylinder doesn't hold even one litre, and anyway it is always full. Modern cars have much smaller reservoirs. (Less than one litre at a guess)

To save money, and be environmentally friendly when I dispose of the old oil, what is the minimum oil level I could use?

Secondly, does anyone make a drain plug with a built-in tap? I have just emptied the reservoir, by CAREFULLY undoing the drain plug, and consequently spilling oil all over the chassis and my barn floor. I spent more time cleaning up the mess than changing the supply hose. (The purpose of the exercise.) (Cost of replacement hose - next to nothing. Cost of replacement oil - 18.)

 

[diyfarmer]

I have a Zetor 6045, and am in Wales, UK.

For what reason does the power steering oil reservoir hold so much oil? The User Handbook says to use 4.4 litres. The power steering hydraulic cylinder doesn't hold even one litre, and anyway it is always full. Modern cars have much smaller reservoirs. (Less than one litre at a guess)

To save money, and be environmentally friendly when I dispose of the old oil, what is the minimum oil level I could use?

Secondly, does anyone make a drain plug with a built-in tap? I have just emptied the reservoir, by CAREFULLY undoing the drain plug, and consequently spilling oil all over the chassis and my barn floor. I spent more time cleaning up the mess than changing the supply hose. (The purpose of the exercise.) (Cost of replacement hose - next to nothing. Cost of replacement oil - 18.)

{First Question} I presume the tank is big encase you get a leak, that you can still steer to safety, also some drivers would have reputation for never checking anything. But to compare a car steering to a tractor is a no-brainer, have you driven a car without PS, up to only the last ten years not every car had PS, but try turning a tractor without PS is hard work.

I would refill the oil the recommend amount, you'll hardly be able to buy power steering in a less size container than 5 litres anyway.

You could had got a fluid vacuum extractor and suck the oil out of the top of the tank, like https://www.youtube.com/watch?v=BFxNd_cVsjk