It had some kind of central hydraulic pump system for the suspension, brakes, power steering, and auto trans.
It was really an advanced concept but not reliable and plagued with leaks.
It was funny, the guy was an old farmer, and also a driving instructor at the high school, practical as hell in everything else he did, but loved those Citroens. They had a deal where you could raise one wheel up to change a tire without using a jack. He loved to demonstrate that feature.
That old guy taught me a lot about tractors and machinery. I hope they gave him a Citroen to work on in heaven.