I hope someone can help as the 3 mechanics I have spoken to are stumped. I have a 2008 Outlander 2.4i Mivec. After a mild side colision the power steering became stiff and so the pump was changed which made it run smoothly. However, I recently drove it 800km to Esperance with no problems, but the next day as soon as I drove onto an unsealed road with corrugations, within minutes I could hear the power steering fluid boiling over. i managed to get to a garage and they changed the reservoir as it was partially melted and looked like the source of the problem. The next day the same happened as soon as i went off road. i have watched it closely and whenever I drive, the fluid gets really hot but copes. If I drive hard around corners or go off road then it boils out of the reservoir. Can anyone please help? Many thanks, Carl.

 

Pressure and temperature are directly related. What is the ambient temp when this happened. If the "mild side collision" caused a passage to become restricted, this could be running up the pressure. Or the wrong pump was installed. Or any combination. That fluid has a very high boiling point. I would not recommend driving around like this. One curious thing is when you describe a lot of motion on the tie rods (ie off road or rough road) the temperature spikes, so something is wrong there. Perhaps the collision messed up the tie rods or the valves where they mate inside the rack?

 

Could be air getting into system? Never seen P/S fluid boil before, but seen it froth/bubble up from air getting in, commonly a plugged filter screen in the reservoir causes this (pump can't suck in fluid fast enough). But since u already changed the reservoir, I guess u can rule that out.

So next I would check for air getting into a line somewhere, (usually wil also leak externally)... or I would suspect a bad power steering pump, last on the list would be a bad power steering rack.