Red69

I recently dropped my PS components for some needed seal work. - its a 69. The fluid in the system is RED... the service manual says to use a GM approved fluid or "AQ - ATF" transmission fluid. I noticed that the fluid my son had been putting in his daily driver is CLEAR... I'm not up on all the current fluid specs.... and was wondering what was the difference between the generic CLEAR fluids and the old RED tranny fluid used in the system? Will the CLEAR hurt the system? Should I stay with the ATF tranny fluid? :confused:

Lt1er

I've used both kinds and I really don't think that it matters that much. ATF have friction additives so it might ware seals a little faster than pure clear power steering fluid.

Smokehouse69

Yeah, either kind will work fine. When I re-did my system a couple of months ago, I used the clear stuff, it had been filled with ATF. It works the same, except now it is making some strange noises when I step on the brakes and turn the wheel. I think the pump is getting ready to bite the dust, that's what I get for not replacing it when I had the rest of the system apart.

GaryS

I think the old GM Service Manuals stated either PS or ATF. I don't think you will do any harm by continuing to use ATF. I personally use PS fluid. I think (big qualifier here) that the colors of the fluids are unimportant, merely a way that you can tell at a glance what you are putting in there. It is similar to the prinicipal of kerosene being red in color so you know you have kero instead of gasoline.
Gary

mrvette

Over the years I think my observations are correct in that using ATF in power steering seems to promote leaking faster than steering fluids....I think this is because ATF had detergents in there which are fine I suppose for an auto tranny, but I have noticed changing fluids on an old tranny promotes failures...many times made this observation on my cars as well as friends....
I think the same from MY personal experience is true of power steering also...
same type of seals, same type of sludge build up, same thing except the friction enhancers necessary for the clutches of a tranny, like Posi additive...
same crap....

I suspect more than anything it's all sales and marketing.....

BUT, I use steering fluid for steering anymore...and nare the twain shall meet...cheap enough....

GENE

69er

While on the subject of power steering fluid how often if ever do you guys change the fluid?
Any negative effects like leaks when changing very old PS fluid?

Jim Shea

The amber colored power steering fluid that is available from GM dealers has been specifically formulated to work with the Saginaw power steering pump. Also, all the pumps and the control valves were validated with the fluid. This is the 32 oz can of power steering fluid with the GM logo on the container. It is available as part number 1050017.

So it is true that the red colored ATF may not damage or cause excessive wear of the pump ring, bushings, seals, etc. But none of the ATF fluids (of which there are many, many, approved formulations for use in transmissions) have never been rigorously tested with Saginaw steering components.

Red69

I guess its fair to say that you cant go wrong with the CLEAR GM brand fluid. Funny thing is that there is no spec on any of the bottles I checked out in the auto parts store. You would think that some sort of code like the API letters used to rate oils would be used. There usually is a part number on the plasic bottle.... but who the heck knows what those mean...

Another thing I noticed when I drained the system.... no water came out...(which is a good thing )there was some brown sludge that came from the piston when the ram was pushed to the both extream. Dose PS fluid hold moisture like brake fluid?

Thanks ;)

Jim Shea

The power steering system really doesn't like water entrapped in the fluid. If there is any appreciable water in the system it tends to "pop" as it travels through the pump. I believe that the "pop" is the water transforming from liquid to vapor and back to liquid as it is compressed and then decompressed by the rotating group in the pump. The fluid then gets real milky and the pump makes all kinds of noise.

Now the pump reservoir is vented to atmosphere. So there is a real minor amount of air (and water vapor) that can enter the pump. As the fluid heats up and cools down, the fluid level in the pump reservoir varies from the "FULL HOT" to the "COLD" marks on the pump cap stick. This variation in volume causes a small amount of air to enter and be expelled in the gap between the top surface of the fluid and the pump cap. But the minor amount of atmospheric water vapor doesn't seem to affect pump operation.