Citroen C5 2008 2.0 HDi - hydraulic pump motor only spins with reversed polarity

Hello. I changed the brushes on the hydraulic pump on a Citroen C5 2008, 2000cc, 136 hp, and the motor doesn't turn. When I reverse the polarity, it turns. What is the cause of this?


AI: What is the exact part number or type of the hydraulic pump/motor, and is it the original pump from the car?
Original pump.
AI: After changing the brushes, did you check that the brushes, brush holder, and wires are fitted exactly as before, and what voltage do you get at the motor with normal polarity?
With normal polarity it does not turn. With reversed it works. How do I measure voltage with normal polarity?

Didn’t you fit the brush holder or the wires in the same position as they were before you took them apart? When the polarity is reversed, does it run and rotate in the correct direction or the wrong direction? Perhaps you fitted the rotor and brush holder on the wrong side of the stator compared to how they were before dismantling? Could you show the rest of the motor in the photos? When dismantling motors, you mark on the stator which side the rotor commutator with brushes is on, as well as the clockwise position of both bearing housing parts in relation to the main part of the stator – did you do this or not? Before dismantling, I usually mark it up and document it with a photo, something like this:

Of course, mine isn’t a DC motor, but I’ve shown you what I mean... In other words, to reassemble it exactly as it was before dismantling...