Power Steering pump whine

[enslow]

I recently replaced the steering rack, pressure line, and PS pump on my wife's 97 Lesabre:
http://www.automotiveforums.com/vbul....php?t=1077384

All went well in the end, except for the PS pump. I can't seem to get rid of air pockets or something. When I follow the prescribed bleeding procedure (raise front end, turn wheel from stop to stop 40 timess, engine off) it gets rid of most air and noise. Then I ran the engine and turned it stop to stop another 40 times. This made the steering very smooth. although I couldn't get rid of the pump whine.

While driving, it works nicely, except the steering and pump slowly get noisier and noisier, especially when doing hard steering while moving slowly, such as for parking.

I then got myself a Mityvac and made an adapter for the steering pump and pumped the reservoir down to 20 in Hg. When I did this with the engine running, the pump suddenly became noisey at about 17 in Hg, then slowly quietened. I though I had it licked so I took it for another test drive. Same thing, fine until I did the hard steering at low speeds. The steering got rough and noisy. When I put the vacuum on again, the pump became noisy at about 15 in Hg, but I got it quiet finally at 20 in Hg.

I left the vacuum on overnight and I just checked it now. Overnight the vacuum held at 20 in Hg. There are no visible fluid leaks.

So far I can only think of two things:
1) there is trapped air somewhere in the system that normal bleeding procedures won't remove.

and/or

2) there is a leak, but downline in the rack somewhere which doesn't show itself until the pump is pulling the fluid from the low pressure line.

Because the vacuum held overnight, I'm guessing that the answer is #1, or something else I haven't thought of yet. Who knows how to bleed these systems?

BTW, the pump is a Fenco rebuild, the rack is Autoline. I would have preferred ACDelco, but neither were available up here in Canada.

[Blue Bowtie]

What oil was used to fill the system? If the oil was not a hydraulic oil with foam suppressant, it may be generating it's own air from pumping. Drawing a vacuum on the system (and oil) should cause the air to explode out of the liquid, but the next day it may just churn up more air again.

I used to get Barnes and Fenner hydraulic power units that would do that and changing to a better (more appropriate) hydraulic oil solved it almost every time. If you can get your hands on some paraffin oil as an additive it might help.

[enslow]

Thanks Bowtie,

I used Kleenflo (#586) which is approved for GM. I would have used a synthetic if I had known about one (I now know of a part-synthetic from GM part # 12345866)

Up here in Canada you cannot find high quality rebuilds, you have to go to the US. I may go down and get an ACDelco rebuild later if necessary.

Would the 20" Hg pull the air trapped in the rack as well? Or does that have to be worked out? Or, does it sound more like the fluid is self foaming?

ugh. New rack, new pump, new lines, new fluid, and the system is working worse than the original. At least my garage floor is clean now.

[danielsatur]

1) Jack the front end of car up.
2) Apply parking brake and block wheels.
3) With the engine running turn the steering wheel in both directions to work out air + flush.

[HotZ28]

Looking for synthetic, this is what I use.

AMSOIL Synthetic Universal Power Steering Fluid provides excellent wear protection. Its synthetic formulation delivers better lubricity and reduced friction, resulting in cooler operating temperatures, longer component life and quieter operation. AMSOIL Power Steering Fluid is formulated with a high viscosity index. Its low pour point ensures immediate lubrication at startup and in cold temperatures, yet it resists thermal breakdown and maintains maximum protection in high temperatures.
Why Change Power Steering Fluid
Power steering fluid is one of the most neglected fluids under the hood because most people don’t think about it unless there is a problem. Consumers realize that power steering systems require additional fluid occasionally, but do not realize that power steering fluid should be changed at regular intervals. Many original equipment manufacturers (OEMs) recommend changing power steering fluid due to the accumulation of wear material and other debris within the power steering system. For example, Dodge recommends changing the power steering fluid in its 2005-2008 Magnum and Charger models every 60,000 miles. In addition, power steering fluid has a service life, just like any other lubricating fluid. It is subject to temperature extremes and must combat contaminants while simultaneously fulfilling its role as a hydraulic fluid.

Applications
AMSOIL Synthetic Universal Power Steering Fluid meets or exceeds motor vehicle specifications for use in GM, Chrysler, Honda, Ford, Volkswagen, Mercedes, Saab, Subaru and Audi applications. Please see the AMSOIL auto and light truck lookup guide for more information pertaining to your specific application.

• Ford 9M2C138-CJ, M2C33-F & ESW-M2C128-C&D
• Volkswagen TL-VW-570-26 & TL-52146
• GM 9985010 Saginaw Power Steering Systems
• DaimlerChrysler MS1872 & MS5931F
• American Motor Corporation C4124
• Navistar TMS 6810
• Mercedes Benz
• Honda/Acura
• Saab
• Subaru
• Audi

Source: http://www.amsoil.com/storefront/psf.aspx

[Tech II]

AS the whine gets worse, look at the fluid in the reservoir.....is air foaming in the fluid? Is the level dropping?

You have bled the system correctly......sounds like a bad part.....

[enslow]

Originally Posted by Tech II

AS the whine gets worse, look at the fluid in the reservoir.....is air foaming in the fluid? Is the level dropping?

You have bled the system correctly......sounds like a bad part.....

Thanks. I did notice that the cold level of the fluid was too high (level when cold was at the hot level). I'll remove some fluid and see. I didn't think these pumps were that sensitive to level. However, I have never seen any foam.

I tried driving up my driveway with the engine vacuum connected to the pump. The steering was VERY rough. At this point, if lower the level to the spec doesn't do it, I guess I'm looking at another pump. And to think I was told the Fenco made good pumps. Maybe this one us a lemon, but what are the chances I'd get the lemon.....

I'm concerned that the rack is just as junky as the pump too. All the local parts stores would supply are Dorman and Autoline, and one other even cheaper one. If I had known about a parts store just south of the border from me before now, I'd have ACDelco stuff in there right now. Alas, I don't and I may have to live with it. I don't really want to do a rack all over again.

[enslow]

Update:
I checked the fluid level the other day and discovered I had overfilled the reservoir. I surmise that the extra weight of fluid above the vanes caused excessive pressures, especially when the steering was under load. This happens when steering while parking, and the steering wheel may be turned near the stops momentarily. The increased pressure will cause heating of the fluid, and I suppose could cause some boiling of the fluid. Boiling fluid is probably even worse than air because not only do you have bubbles of vapour, they're superheated.

If my surmising is correct, I have have wrecked my power steering pump, and the pump may have been good in the beginning. It still moans under load, but I don't get the feeling of trapped air anymore. Time will tell if I have to replace this new pump.

Moral of the story if you are replacing a system (rack and pump):
1) bleed according to the service manual first. This involves raising the front, adding fluid, and turning the wheels from stop to stop 40 times while keeping the fluid topped up. Make sure the fluid is at the correct level.
2) Follow ACDelco's updated bleeding procedure:
ACDelco TechConnect - Technical Product Service Aid

An adapter is easily made for much cheaper by purchasing a Dorman power steering cap
a) cut off the dipstick end just below the spring
b) using a long drill, drill through the small hole of the remaining dipstick right through the cap.
c) using a bit slightly larger than the end of the cut-off dipstick, drill an 1/8" hold through the top of the cap.
d) JBweld the cut-off dipstick onto the top of the cap. This will be a vacuum hose barb.
e) lubricate both sides of the orange seal with silicone dielectric grease. Wipe off the excess.
Congratulations, you now have a vacuum adapter that is much better than anything you could buy, and much less. I'll try to take a picture of the adapter and post it later. The ACDelco site says that a loss of vacuum of 2-3" Hg is normal. That is because their adapter leaks! My adapter holds a vacuum of 20" Hg overnight with no signs of leaking. Now get yourself a Mityvac pump and some vacuum hose. (The Nalgeen tubing the Mityvac comes with will collapse with the heat and vacuum.)

In general, I would recommend ACDelco parts unless you know for a fact the part you're putting on is better quality.

Good luck!

[enslow]

The whine was still there, and there is a little roughness in the steering at low speeds, so I added a little Lucas power steering stop leak, maybe about 100 mL (30 ounces or so). This almost immediately made the power steering pump MUCH quieter, but the moaning and roughness during low speed steering is still there. It may be overfilled again at this point by 100 mL, so I may have to remove a little.

It's looking more and more like Tech II has the true and ultimate answers, a bad part. If it's still rough and moaning by the summer I'll get an ACDelco reman. I should be able to keep the reserevoir.

[Jrs3800]

When I did the 3800 series III swap into my van I tossed the original pump due to whine... I have dealt with aftermarket pumps before and decided to use a newer Power steering pump... I believe it was an 05-06 3800 pump... Its been flawless and quiet... My 03 Bonneville has the same pump and its also quiet... My 95 Series II has always made power steering whine noises... Now at 194,000 ish still makes the same sound... But that pump will be replaced when I update the car...

I'd say either the AC Delco Reman unit like you are thinking or get a newer unit from a wrecker...

[gcrawdad]

Enslow, I had the same problem with the bleeding procedure. I don't see how that GM adapter can possibly work on any reservoir that has the two cutouts for the cap. You can push the adapter in there all day long and it's not going to seal. I happen to have one of those analyzers that can tell if you have exhaust gas leaking into the coolant. Anyway, this device has a tapered rubber plug to fit into the coolant reservoir. Of course, it didn't work on the ps reservoir until I had this extraordinarily brilliant idea to to put an o-ring on it to cover up those two openings. It worked and didn't leak an inch. A little oil on the o-ring may help.

[enslow]

thank you for your reply. That would work too.

I'm still convinced the current noise I still get is because I got a cheap pump.

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