Hello US municipality, when changing the pressure hose from the servo pump to the steering gear of my 73 Eldorado I had the problem that after that there was no steering support anymore. After days of troubleshooting, ten times of venting and so on. I suddenly fell on a loosely lying in the engine room hydraulic part which I could not assign at first. Only when I had removed the servo pump I knew where it belongs. The solution: When the hose had been removed from the pump, the connection piece with the hose dissolved. Since I had not drained the oil was not noticed that the ominous part, it was by the way the pressure control valve, escaping itself because of the spring behind it into the cover in front of the steering gear. If you only remove the hose, therefore without the connection piece, this can not happen by the way. Valve cleaned, everything reassembled, servo pump installed, connections screwed on, oil filled, With running motor steering wheel two-three Let’s go to the left and turn right to the stop, to ventilate, replenish oil, done. Completely easy. If I had found the valve niht I would have bought a new pump. Lucky. So Long