Which part specifically causes a power steering pump whine?

[Twisted1]

I've always wondered, but never found out which part exactly in a power steering pump assembly causes the pump to whine. I'm a Ford owner so they whine regardless..

 

[JimPghPA]

You do know that they whine because they are low on fluid, don't you?

I think it because of air getting into the actual pump section that has the centrifugal veins and compressing air.

 

[Twisted1]

Not always. I replaced my PS pump with an AC Delco unit and it whined from the beginning.

 

[SwampSurvivor]

Originally Posted by JimPghPA
You do know that they whine because they are low on fluid, don't you?

I think it because of air getting into the actual pump section that has the centrifugal veins and compressing air.


I think every 90s Ford left the dealer lot brand new both full of PS Fluid and whining.

 

[Twisted1]

Exactly. I'm just wondering which part internally causes that whining

 

[BigCahuna]

A dry bearing.,,,

 

[Ded Mazai]

The housing. When it wears it loses the original smooth shape.

 

[sloinker]

I imagine it's the shaft riding against the front bushing/bearing being pulled by belt tension.

 

[samven]

I am still trying to figure out why some hydraulic pumps whine and others dont. The best I have come up with is fluid weight. I notice more whine in cold temps and have found some manufactures of pumps spec thinner fluid in the winter or have moved to multigrade synthetic fluids. Weather this translates to power steering fluid or not I dont know.

 

[Ded Mazai]

Tried to find a video explaining why the pump starts to whine. Couldn't find anything in English. There is one in Russian.

https://youtu.be/8k9rQmbC8aQ?t=706

The guy shows with his finger the place where the wear takes place.

 

[Twisted1]

Thanks a bunch fellas!