PS pump internals beyond hope? (pics)

[BVRPLZR]

Hi everyone, 88 G20 van with a 350

I tore apart my PS pump today to re-gasket it as a little winter project.

Now looking at the internals, the thrust faces of the rotor are pretty chewed up and I’m wondering if this level of wear is typical of a 30 year old Saginaw pump or if I could try my luck at the treasure yard for something better.

The power steering worked great prior to disassembly, it was just a bit noisy, so I’m not ruling out just slapping it back together and calling it good.

Or at least I’m pretty sure it was the PS pump that was noisy. Sounded kind of like servo whine from that corner of the accessory bracket. But maybe that’s just the sound these pumps make? This is my first old GM.

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I’m posting from my phone so I hope these photos aren’t insanely huge.

 

[SAATR]

He's dead, Jim...

I can guarantee that you'll find something better without even trying hard. That is chewed to rat-****.

Should look more like this:

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I'm sure the inside of the rotor housing is just as grooved and ugly.

 

[BVRPLZR]

I assumed as much

Actually the walls of the cam are in pretty good shape.


I work at a factory that makes pump components for GM, so I see the modern counterparts of this pump all the time and they’re brand spanking new so I thought maybe my expectations for the old parts were too high.

It’s miraculous how well the power steering worked with the pump in this condition though. Good engineering.

 

[SAATR]

I assumed as much

Actually the walls of the cam are in pretty good shape.


I work at a factory that makes pump components for GM, so I see the modern counterparts of this pump all the time and they’re brand spanking new so I thought maybe my expectations for the old parts were too high.

It’s miraculous how well the power steering worked with the pump in this condition though. Good engineering.

Interesting! I'm actually surprised that the housing isn't chewed up. The amount of foreign object damage on that rotor makes me wonder how the rest survived. The pump pictured is my 24 year old original, for reference. Vane pumps, like gear pumps, are pretty resilient if you keep debris out of them and oil in them.

 

[BVRPLZR]

So here’s a thought: in the vans, the fluid reservoir is connected to the housing via a length of tubing. I wonder if the truck style housing helps the pump stay better lubricated because the fluid is right there.

Maybe I should source one from a truck?

 

[SAATR]

So here’s a thought: in the vans, the fluid reservoir is connected to the housing via a length of tubing. I wonder if the truck style housing helps the pump stay better lubricated because the fluid is right there.

Maybe I should source one from a truck?

I doubt the location of the fluid reservoir has any direct bearing on the longevity or condition of the pump's internals. As long as there isn't a restriction in the return side of the system, the pump won't know the difference. Hydraulic systems often have remote reservoirs with no loss of pump service life.

Given the damage to the rotor of your pump, I would almost bet that the pump is a reman and that rotor started life in another pump that ingested metal and was reused with new vanes and a serviceable outer pump body. If you know that it is completely original, then I have no idea how the rest survived.

That said, I would grab whatever you find that looks unmolested and has the lowest miles. I don't THINK there is any difference between truck and van pump internals on Saginaw pumps (you would likely know better than I). Obviously, your pump shaft has a groove machined into it that mine does not.

 

[Schurkey]

Does the scored part of the rotor--that holds the vanes--touch anything but the vanes, and the fluid?

I'm thinking that aside from holding the vanes, it never contacts anything else besides the fluid. In which case...who cares how scored it is? So long as the vanes move freely but without excessive clearance.

The pieces that the edges and tips of the vanes ride on have to be fairly pristine, though.

 

[BVRPLZR]

Does the scored part of the rotor--that holds the vanes--touch anything but the vanes, and the fluid?

I'm thinking that aside from holding the vanes, it never contacts anything else besides the fluid. In which case...who cares how scored it is? So long as the vanes move freely but without excessive clearance.

The pieces that the edges and tips of the vanes ride on have to be fairly pristine, though.

Exactly, I'm not sure that the edges of the rotor come into contact with the walls of the cam at all.
I had my boss look at it and that was the first thing he said, that the rotor doesn't actually contact the walls of the cam.

I think I might still go grab another one from the junkyard because in addition to all the grooves in the rotor, the threads on the inside of the shaft have completely corroded away so I'd have to tap it out in order to reinstall the pulley.

Plus, I'm kind of curious to have another pump to compare it to. My vehicle had not been well cared for in the years before I bought it so tearing it all apart is kind of a great lesson in regular maintenance.

 

[BVRPLZR]

Some photos of the inside of the cam ring for anyone curious

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[Scooterwrench]

Some photos of the inside of the cam ring for anyone curious

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Is there a lip on ID of that slide? That would be an indicator of wear. If you run your fingernail across the inside of that slide and it hangs on a lip you may want to consider a salvage yard pump to rebuild. With the current neglect for QC these days you'd be better off doing the rebuild yourself.