What about Power Steering Fluid

[Paul S]

Creeping farther and farther away from that 100,000 mile mark I am starting to pick up a whine that apears to be coming, if not from the power steering pump, then at least a sheave located in that network.

My question is, aside from motor oil and transmission fluid, does the power steering fluid ever need to be changed?

Also I could use any tips on determining the source of the whine, whether it be the PS unit, Idler pulley or something else. The water pump has been changed about a year ago.

This is on a '99 STS. Thanks in advance for any pointers or help.

Paul S.

[rockfangd]

my best tip is to buy a baster and suck up the fluid in the reservoir, then refill it with fresh fluid. Repeat this about once a month for a little while and the whine should disappear.

I use this route because I find changing the fluid all at once on a vehicle that has higher miles/age tends to make components fail.

I have done this on all of my vehicles and all of them that had the whine has gone, and have never had a pump, rack, or line go bad.

[Cadillac Jim]

Most power steering whine noises come from foam (air) in the fluid, usually from the fluid being so low that air is sucked into the pump. Adding fluid does not get rid of the whine immediately because the air must work out, e.g. circulate to the reservoir where the emulsified air migrates to the top, coalesces into bubbles, floats to the top and dissipates. This can take from a few seconds to a couple of hours of driving. The power steering fluid will be low by an amount equal to the volume of air that escapes this way so topping it off when the whine goes away is a good idea.

As for replacing the PS fluid, I would go by color and smell. If it is still transparent and the smell is normal for transmission fluid, and the color is similar to that of new fluid, I would leave it alone. If it is noticeably old, I would flush it. Since power steering systems are not usually designed to be drained or flushed, the procedure suggested by rockfangd is probably the simplest effective way to do it yourself. Otherwise I would let a shop with equipment and experience do it.

[Jan Olsson]

There is a factory procedure that comes with a new pump. One procedure for flushing and one for purging the air. I'll do a write up from my memory. I can post the correct procedure if there is an interest.

Here we go then! To flush you just have to raise the vehicle with a jack so that the wheels can move freely. Always use stands! Then disconnect the return line (the one connected to the reservoir). You can buy a yard of hose with the same dimensions and temporarily connect to the return line in order to be able to collect the old fluid in a gallon jug. Use 2-4 quarters of new approved fluid and have an assistant start the car. You must be prepared to immediately pour the new fluid in the reservoir and keep the level at full cold all the time. Continue until the fluid from the return hose is clear and stop the engine. Connect the hose and turn the steering wheel from left to right. Center the wheels and have the assistant start the engine once again. Be prepared to keep the fluid level at full cold. Let the engine idle for 10 minutes. Stop it once again. Disconnect the hose and repeat the previous steps to check for discoloration off the fluid. If it looks fine it's time to purge the air. Otherwise repeat once again. I used 3 quarters.

To purge the air,keep the engine off and turn the steering wheel from left to right 20 times.

Something like that anyway. I can get the procedure and write it down if you like.

[rockfangd]

that is the procedure I am not too crazy about on older vehicles. I find the rapid change of fluid from old to new tends to be too much for the older parts. Just my opinion. Done regularly would be a good thing.

[KHE]

Creeping farther and farther away from that 100,000 mile mark I am starting to pick up a whine that apears to be coming, if not from the power steering pump, then at least a sheave located in that network.

My question is, aside from motor oil and transmission fluid, does the power steering fluid ever need to be changed?

Also I could use any tips on determining the source of the whine, whether it be the PS unit, Idler pulley or something else. The water pump has been changed about a year ago.

This is on a '99 STS. Thanks in advance for any pointers or help.

Paul S.

I don't believe there is a "change schedule" for power steering fluid. If it makes you feel better, change it but if you're receiving a whine, the system is sucking air from somewhere in the system.

[Jan Olsson]

that is the procedure I am not too crazy about on older vehicles. I find the rapid change of fluid from old to new tends to be too much for the older parts. Just my opinion. Done regularly would be a good thing.

The only ways that I can see making the fluid change harmful are if you use the wrong type or if the old fluid has degraded in a way making steering components work better. Like debris changing the viscosity and making components less prone to internal and externat leaks. Just speculating here.

I would definitely change the fluid if a component fail just to make sure most of the debris from the failing part gest out.

[Paul S]

Thank you all for your response to this problem, I suppose I have my weekend chore cut out for me but I now have a direction to follow rather than standing next to the car scratching my head.

[Texas Jim]

Thank you all for your response to this problem, I suppose I have my weekend chore cut out for me but I now have a direction to follow rather than standing next to the car scratching my head.

Using the turkey baster method, you don't even get your hands dirty....

Suck out as much as you can with the turkey baster and then add new fluid to the full mark.

Repeat every week or two for a half dozen times and it will be 90% or better all new fluid.

[rockfangd]

has worked like a charm for me.

When I bought my 96 it whined alot. fluid was horrible.

I did it once a week for 2 months and never replaced anything. problem went away and I forgot all about it. Fluid is good now. I refresh it once a year

[JohnnyG]

I have a question. Can Dexron VI be used in the P/S pump? We used to use regular Dexron III to top off the level, but now GM and many others sell power steering fluid specifically for that purpose. I haven't looked it up in my owners manual, but what do younz guys think?

[Texas Jim]

I have a question. Can Dexron VI be used in the P/S pump? We used to use regular Dexron III to top off the level, but now GM and many others sell power steering fluid specifically for that purpose. I haven't looked it up in my owners manual, but what do younz guys think?

In the owners manual it is a different part number... but as too using Dexron Vi in the power steering, I don't know the answer to that.

[KHE]

Some cars used to use trans. fluid in the power steering syster but I don't think any do today. None of my cars - even those back in the late 1970s used trans. fluid in the power steering system.

[Cadillac Jim]

I never heard of anyone using transmission fluid for the power steering, other than a Ford or two many years ago. Power steering fluid is more like what I think of as ordinary hydraulic oil. ATF is formulated in part for its dynamics in torque converters and its effects on clutches, and seems a lot more viscous than power steering fluid to me.

[rockfangd]

I would not use any kind of ATF in the power steering system unless it calls for it.

I am very familiar with systems that use transmission fluid but they are not cars. All having GVW over 8600. IE buses, trucks, etc... Even those are getting to be less.

[Texas Jim]

I never heard of anyone using transmission fluid for the power steering, other than a Ford or two many years ago. Power steering fluid is more like what I think of as ordinary hydraulic oil. ATF is formulated in part for its dynamics in torque converters and its effects on clutches, and seems a lot more viscous than power steering fluid to me.

Back in the old days, transmission fluid was all I ever used.

Type "A" then later Dexron...

That being said.... I "WOULD NOT" use it today in modern cars.

I may be mistaken, but I seem to remember that the owners manual specified TYPE A for the poser steering....

[Cadillac Jim]

I wouldn't be surprised. When I was young I rarely had a power steering car myself. Even that 427 Corvette did not have power steering. The Corvettes that *did* have power steering were at a big disadvantage in the gymkhanas because it limited how quickly the wheel could be turned. My first car with power steering was about 1970 and I never looked at it on that car. In fact I don't think that I ever had an issue with power steering on any of my cars.

So, basically, I don't know much about older power steering systems. I do know that Ford had a hydraulic power brake system for a year or two but losing the power brakes the second the engine dies killed that pretty quickly.