No power steering *broken pump shaft* (Now with pics)

[Fred_M1010]

A friend of mine just called me for advice on his power steering, but I could come up with any more ideas...
At first he had no power steering at all, and the dipstick for the power steering oil had melted
I guess he ran with too little oil and burned up the pump.

So he bought a new A1 Cardone pump from me, that had been laying in my garage for a couple of years,
and installed that one.
Still no power steering...
I instructed him to bleed the system, but that didn't help either he said.
Now he's installed a new steering box as well, but it still doesn't work........

Any ideas?

Btw it's a 93 W250 5.9ctd

[Fred_M1010]

Btw I asked him to check that he haven't mixed up the hoses for the steering box,
but he claims that they wouldn't fit if he had.....

But as I recall, the fittings are the same, aren't they?

[Fred_M1010]

He got it running now.
He changed back to his old pump, and it worked right away.
So it must have been the old steering box that was bad.
And apparantly my new pump didn't work either...

[Richie O]

It also could have been air bound. I have had issues before when it took a couple days of friggin with it to get the air out. I have even had them work great and then down the road stop working. I had to work the air out again and it has been fine since.

[Fred_M1010]

It was a broken shaft inside the new pump...
And it's probably to old for a refund...

[Fred_M1010]

I recently got the pump back from him.
Here's how the shaft looks:





Could a bad installation cause this shaft to break like this?
or could it have been bad from the start (manufacturing error)?

[ellis93]

I'd say it could go either way. If it was an install problem it would be that its tangs were not aligned and it was pulled up with the pumps mounting bolts. This would jam the pumps internals causing the shaft to twist and index itself after seizing the pump, thus shaft breakage. DON'T Ask me how I know this

[Fred_M1010]

I took the pump apart to inspect it further:

The "sides" of the pump housing and pump wheel seems to be worn:
Rear part:



Front part:



Strange thing is it seems to be more worn on the front than the rear.
If it had been forced to the rear by misaligning tangs, wouldn't most wear be at the rear?

The pump housing itself (or what it's called) looked like new:

There was some strange wave-like honing pattern (barely noticeble in the pic) but nothing that looked like wear marks.

But judging by the way the paint hasn't been chafed off all the way here, I'm thinking that it might not have been seated properly after all...or what do you think?

[ellis93]

Well.....guess it was installed right. Might have had a vane stick or had a piece of trash run through it. Idk.

[PToombs]

No way trash went thru it. The sides of the center housing where the vanes run would be scarred to siht. My bet is with misalignment on installation, all the wear is on the rotor and where it hits on the end housings. Look at the ends of the tangs on the shaft and see if there are any marks there. That may show something.

I've seen lots of bad hydraulic pumps at work. Usually you can tell what happened pretty quick.