Ford power steering

BlakeS94

Have a '10 Mondeo, power steering works but is meh, decided to flush the fluid and change.

The method I used for this was to raise the front on jack stands, remove PS fluid return line going into the reservoir, connected that to a separate hose going into a drain pan, plugged the open return line hose that was on the reservoir. Turned the steering wheel with the car off to force old fluid out, used about a litre to flush it, wasn't too dirty I just wanted to be thorough.

After flushing I connected all the hoses back up, and turned the wheel multiple times *slowly* with the car off and the reservoir cap open to bleed any air, topped up the fluid once more, put the car on the ground and let it idle with the cap open for a few minutes, let it cool down, went back out and turned the wheel with the cap off but wheels on the ground this time.

Took it for a test drive, and while it is better, it's still not great, so any ideas as to why? Still air trapped in the system or something, the rack has no leaks and no play in the steering, the pump makes a very slight whine when I'm near full lock on either side. But other than that is quiet.

I also gave the reservoir a good clean inside and let it dry before reinstalling.

Correct spec was used WSS-M2C204-A

It is possible to do right way and redneck way. I will look to you the right way later, but redneck is next: suck the fluid out, fill, run, suck fluid out, fill, run. Couple of liters fluid and it is good as new.

CreadanLady

These don't need bleeding. they bleed themselves after a few minutes running.

3 potential faults.

relief valve is knackered

pump is kackered

internal seals on rack piston are knackered.

On a 12 year old car, I wouldn't be bothered with changing fluid let alone going digging around in the innards of it as long as it is working reasonably well. What would be the point.

BlakeS94

https://www.boards.ie/discussion/comment/118819914#Comment_118819914

Fair enough, I should leave well enough alone so, it's going grand just seemed like the power steering could be better, at least now I know there's fresh fluid in it

BlakeS94

Went for another spin just there, it is actually much better than I originally thought, before I was met with some resistance mid-steer and now it's smooth turning both ways.

I have bad strut top mounts too so the steering wheel doesn't flick back to centre so easily but that's another problem for another day.

BlakeS94

https://www.boards.ie/discussion/comment/118819914#Comment_118819914

Pump is getting louder again and steering becoming more stiff and slow, I reckon pump is knackered so will probably change if it worsens, would make sense to change the PS reservoir along with it. Apparently these MK4s don't get along with their power steering system according to a few talkford forums.

BlakeS94

It's definitely the pump, can't seem to pinpoint anything that would make me think it's the rack, and when I rev the car and hold at about 3000rpm the steering is much lighter, must be that the vanes inside the pump are shot. Steering is quite heavy at slow speeds now.

BlakeS94

https://www.boards.ie/discussion/comment/118819914#Comment_118819914

I think you were correct in saying the pressure relief valve, power steering suddenly feels okay, so maybe that valve was sticking and somehow unstuck itself? PAS is nicely weighted now as if there wasn't an issue, either that or the car heard I was going taking it apart and stopped misbehaving lol, still cause for replacement I reckon.