The rack and pinion on my wifes Volvo had a "hard" spot, bought the Lucas Power Steering stuff.
Flushed the system and then added the Lucas with new fluid.
The hard spot is now gone but she now needs a new power steering pump.
It whines like nobody's business for 6 months now but still works fine.
I have since flushed it twice and the whine is still there.

 

My question is this a bad pump? Would a bad pump cause air bubbles/foam and overflow of the reservoir? I do not see any other leaks from the hoses but have heard it can suck air in if the o ring goes bad at the ps pump hose connection. When the car has been sitting and not driven thus no air in the reservoir the pump makes no noise and is fine. Only after I drive it for a while it starts to whine from the air in the system.

 

It has to be the pump, having a valve stuck or you are sucking air, my money is on the pump.

 

The reason the pump is whining is most likely all that goo you put in there has traveled to the low pressure side where it tends to seriously narrow the inlet for the pump; it is starving for fluid and cavitating like crazy. When the pressure of a liquid drops below it's vapor pressure - vapor forms! This is where the bubbles are coming from if they are lots and lots of them and they are very small. Here is a picture of a boat prop cavitating:


Note the bubbles forming on the trailing edge of the prop.

Cavitation is not a problem in and of itself, only when conditions are right and the shockwave of the following blade encounters the bubbles and forces them to implode close to the trialing edge of the leading blade. When this happens, the force of the implosion of the tiny bubbles takes a little bite out of the blade, as it were. This is why some pumps may sing for their supper for years, others under the right conditions only a few minutes. (Actually, for the engineering types out there, this is really a "guess", nobody really understands the process of pump destruction via cavitation, if they say so they are full of it.)

Anyhoo, a little Sunday morning science for everybody. Enjoy the day!

 

Pretty impressive presentation Mr Geek. Where did you get the picture?

 

Steering pump started leaking today. Is leaking around the seal between the two halves. Where is the best place to get a replacement? Any luck with the remanufactured ones such as napa or advance auto? Will a Chevy S10 w/2.5L and the p/n is 20-874 from napa be a direct replacement. Only 70 bucks for it.

 

Wow that sucks. So now hoping that the stop leak would stop the leak, it hasn't and now has created problems with the pump. How long did you give it to run on just 1/3 of the bottle before you added half?

My gearbox is also leaking at the pitman arm, and after having got shot down from every source for a rebuilt box, I was going to give the shepard stuff a shot. I think I will pass and just replace the gearbox. I understand that at 1/3 a bottle a guy is probably just fine, but I'm just gonna replace it anyway. Thanks for posting this warning.

Truth be told I've never been comfortable with any stop leak product.

 

I think you'd be just fine with a rebuilt one from napa.

 

You have to givve the white shepherd at least a week of daily driving. I think the OP got a little anxious and added more. Only 1/3 of a bottle and I would do a flush first. Start with new fluid. Once it stops, I would swap the fluid again. White shepherd will thin the fluid out, that is why you only use 1/3 of a bottle. The Lucas PS stuff is way too thick and will starve the pump. If you get on the highway with the Lucas in, you will be buying a new pump.

I had a leak at the pitman arm seal. I trimmed the hoses, made sure the pitman arm was tight, and still had a slight leak. I tried the Lucas and burned out my pump on a trip to Dallas. After replacing my pump and flushing several times (I would flush before replacing the pump), I added 1/3 bottle of the WS. It stopped within a week, and I swapped fluid again because it felt like it was starting to slip a little.

Use it for at least a week of regular driving, but no more than a month. That is my opinion. Do not add anything else, just wait. If it still leaks, you need a new box. I would also again stress the hoses and tightening the pitman arm...

 

Cool, thank OK!