[Steering & Suspension] Power Steering gone - reservoir full, hoses and belt seem fine

[mrak]

Hi there, hoping to get some help with diagnosing a problem.

Parallel parking yesterday I heard a screeching sound (sounded a bit like a belt, but maybe metal) and then my power steering went out. I finished parking, let the car be, went back an hour or two later, started it up, seemed to have power steering for a few seconds, and it was gone again (and still is). Checked the reservoir today and it's full. Looked around the hose coming from the reservoir and it doesn't look like there's been a leak anywhere. Aux belt seems to be taught and moving fine.

Any thoughts on what I should check next?

Thanks!

[cancunia]

It's maybe the pump.
Not sure how to test it though.

[mrak]

Yeah, thinking the same, but thought there may be some other stuff to try first...

[Sol]

Most probably the pump has suffered an internal mechanical failure. The screech would be the moment the pump stalled and the belt squealing as it tried to move it. It's basically a vane impeller pump so not many parts to it.

There is nothing else to try if the belt isn't snapped, the pump drive pulley hasn't come off and there isn't a big pool of power steering fluid. 

I guess all you can do is get it tested or replaced at a garage or just swap it yourself. You're lucky the pump on an M59 is mechanical and costs about £70 for a new one. The B9 is EHPS (no belts, all electric) and they start at £500 for a replacement. They aren't too big a job to change but must be done with cleanliness so no grit or dirt gets in the system. Or the power steering rack gets it next...

Hydraulic pumps generate massive pressures so there's not much you can test at home. It either assists the steering or it doesn't I'm afraid. Belt, pulley, burst hoses and low fluid are the only things that can go wrong other than the pump itself and you confirmed the others are not obviously faulty.

Try here for a replacement:

https://m.sparepartstore24.co.uk/citroen...ering-pump

[Romahomepete]

I did mine on our 1.9D Romahome about 6 months ago, a starightforward job but I had 2 special tools.

1 an open ended spanner on a length of pipe for moving the belt tensioner, when I have taken the tension off the belt I can jam it so that I can ease the belt off the pump pulley without having to take the belt right off.
2 I made a crowsfoot spanner bu cutting th eend off an open ended spanner and making a square hole to take a long extension, this was to undo the nit on one of the hydraulic pipes that is PITA to get at otherwise.

The mounting bolts re a bit of a fiddle, I seem to remember that they are allen bolts and I used sone long ball end allen keys to remove them

Peter

[Gadgetman]

What worries me is that there's no filter between the pump and the steering rack. If any metal got ground off when the pump failed, you may end up losing the rack also, soon.

I would probably disconnect the feed hose from the steering rack and flush it somehow.
(Sitting back and waiting for the more knowledgeable to come with better advice. It usually doesn't take long... )

[mrak]

"If any metal got ground off when the pump failed, you may end up losing the rack also, soon."

That doesn't sound good! I was going to give the replacement a go myself, but if I need do anything a bit more intensive to avoid f**king up other parts maybe I should take it to a shop.

I guess on the bright side it's not done very much driving after it failed...

[Sol]

To be honest if you can work a set of tools and you're careful, you probably do as good a job as a garage for this type of repair. They'll just swap the pump and fill the reservoir again. Turn the steering lock to lock a few times to bleed it and give it back after checking for leaks.

I'm surprised there's no gauze in the pump outlets to catch debris. Being as the impeller is probably alloy, even a magnet is no use to catch bits that grind off.

On the plus side, it's likely the impeller has fallen off the end of the pump shaft. Maybe without much contact so while there probably is some element of debris in the pump chamber, the pump stopped suddenly so didn't pump it round into the rack cylinder. Maybe theres a power steering specialist in London who can flush it out.

[jj9]

I've had the front bearing on a PS pump fail and that gives off quite a metallic rattle, I can't recall if the steering became stiff as it was quite a while back.

The links below are of the same sort of pump being stripped down, you can see the front bearing in the 4th picture.

There doesn't look to be a lot to go wrong inside but you never know.

Part 1

Part 2


.

[mrak]

Thanks, everyone. I guess I'll give it a go myself. This looks to be the right pump, yeah? https://www.ebay.co.uk/itm/New-Power-Ste...8TU5JP4%29

Any other tips on consumables/special tools I may need? Best if I don't get halfway through and find out I'm missing a washer of some sort!