What Type Power Steering Fluid

[KAD36]

This weekend I replaced the power steering hoses on my 55. I got them from CARS in NJ. The return hose was wrong (here we go again), so I put the old one back on, the pressure line was correct and had the same diameter lines as the original at the pump and at the gear. I drained the old oil, cleaned the resevoir, and refilled with Dexron III. Fired her up, let it idle and worked the gear and waited for the system to bleed the air out just like the manual said, then took it for a ride. Now the pump is noisy and it wasn't before the job. The pump is original. Any ideas?<P>The last time I did this I could still get my hands on a can of Type A fluid, which is what is called out. Is Dexron III that much different than Type A for this purpose? The manual suggests that heavier oil viscosity could cause the noise. What do you use in a Safety Power Steering unit that calls out Type A?<P>Thanks in advance for your advice

[Jyrki]

Ken, Dexron III is as thin as it can get, thinner than any previous ATF. Also, it will not have the lubrication properties needed. I quess you have most noise when hot? Get a can of real Power Steering Fluid, I think GM still makes it. I use Red Line Power Steering Fluid, and have cured many "moaning" pumps and leaking boxes with it. There are many other makes that carry a specific Power Steering Fluid. ATF is a poor substitute.

[NTX5467]

GM claims Dexron III is backward compatible all the way to 1949 in its automatic transmissions. You might find some Type A fluid at some auto supplies in some obscure brands but Type A in the main brands basically disappeared when Dexron came into being in approx 1968.<P>GM still makes a specific Power Steering Fluid in quarts and pints. Later power steering systems require it. It has a little different additive package and appears to be more waxy than ATF. <P>GM also recommends using a hand held vacuum pump pull a slight vacuum on the power steering reservoir to remove the trapped air in the system. It's covered in a training tape of recent vintage from their factory training satellite broadcast. This works better than doing the previous turning the wheel side to side procedure.<P>Dexron III might have better flow characteristics to be more compatible with the newer transmissions and their electronic solenoid controls and it seems to shift just a bit quicker than the previous Dexron II or Dexron IIE in my Turbo 350, but I somewhat doubt it will cause any noise problems as you mention. Maybe I'm incorrect in that presumption, but all of the literature on ATF upgrades supports Dexron replacing Type A in all situations I'm aware of.<P>ATF typically is thinner than power steering fluid and probably will have a higher detergent additive package for many reasons. Every car I've bought that had ATF in the power steering tended to leak until I changed the fluid back to power steering fluid.<P>Enjoy!

[KAD36]

Thanks very much Jyrki and NTX5467 <BR>for the replys and information!<BR> <BR>The fluid was nice and red - no foam in it as the engine ran so I assume all the air has worked its way out. I also checked that the vent on the washer on the cap of the pump was facing the right way and it was.<P>I made another subtle observation last night after driving the car a few miles - okay - so it was after I stared at it for an hour wondering what the heck I did to it this time and if I could rebuild this pump myself - there was a big wet splash mark under the hood of the car. I traced the source of the splash to the mating surface of the power rack to the steering gear. Looks like a shot of power steering fluid worked its way up through that seal. This must have only happened once or twice because it doesn't leak now, but that mating surface is a little damp, and the whole gear has been good and dry prior. Nothing dripping while it was running. I swung the wheel hard left and right quickly and observed no more splashes. The hose connections are all bone dry. Maybe the thinner Dexron III worked its way through this seal and it only happens at higher RPM?? Does that make any sense? Why wouldn't it leak all the time if a seal went bad? <P>In any event, I re-torqued the 4 bolts that hold the rack to the gear. They were a few ft-lbs loose. I think I will also go and find some GM power steering fluid, suck out the Dexron and try that. Can't hurt at this point as I have no cans of Type A left in the garage and none found in my area. Is the GM power steering fluid compatible with the Dexron III or do I have to flush the whole system out?<P>thanks again

[Jyrki]

Ken, you don't have to flush. They are compatible. Just disconnect the return hose and drain it.<BR>I'm sure Dexron III is compatible backwards in an automatic transmission, but not when used in a steering pump!<BR>I recently purchased a hi-perf AGR steering box for my 79 G-body, and the instructions stated that Dexron ATF does not have the lubrication abilities needed, and neither ATF nor any other "red" hydraulic fluid should be used on a late model system, because they "eat" the Viton seals.<BR>Jyrki

[KAD36]

Hi<P>Just wanted to follow up in case anyone does a search on this topic for a similar problem - I finally got around to finishing this job today. Those new power steering hoses really made the radiator hoses and all the 36 feet of heater hose look ratty, and they were about 10 yrs old, so.... Funny how that works.<P>I fired up the car, thinking maybe if it sat awhile without antifreeze and radiator hoses in it the steering pump noise would go away - nope. So, I flushed out the Dexron III and replaced with GM power steering fluid. BIG DIFFERENCE!! My steering pump is back to being nice and quiet. <P>However, my new intermittent leak between the steering gear and power rack persists, however, and has me stumped.<P>Anyway to remedy this without pulling the steering box? Has anyone ever pulled a steering gear assy from a 55 and how tough is it? I read the manual and it looks like one long shaft right to the gearbox and no split coupling on the steering shaft. Ugh!<p>[ 08-04-2001: Message edited by: KAD36 ]

[Guest nailswede]

Howdy!<P>what brand is that GM steeringfluid?<BR>AC DELCO maybe?..i should try whith that oil to!!<BR>just have to find it over here <P>Anders<p>[ 08-07-2001: Message edited by: Anders Larsson ]

[Guest]

Anders, since you're in Sweden you should have plenty of Red Line dealers there. Give Bert Jareblom, of Lubricare AB, a call to find a dealer. Use Red Line Power Steering Fluid, especially if you are driving during winter months.

[Guest nailswede]

okey jyrki i should look for some good powersteering oil!!

[Jyrki]

Anders, you've got a real nice car there <BR>My uncle used to work at the Volvo engine factory in Skovde, Sweden, and when I was a kid, we would pay a visit there every summer. What made an impression was the huge amount of convertibles (cabs as you call them). Oh well...

[Guest nailswede]

Thanks jyrki!<P>the car runs great to! low miles make som difference <P>In that part of sweden you mentiond there is a lot of classic car in very good shape <P>Anders

[old-tank]

My experience with power steering noises in my three 55's: I had no noise until I changed the hoses, specifically the pressure hose. The original hose is made in sections and may create more resistance to fluid flow than the single section replacement hose (theory). Anyhow on my unrestored Century I put the original hose back on in preparation for showing in the Achival class at the Columbus nationals and the noise went away. On my other two I just added STP to thicken the fluid and the noise is gone until the fluid is really hot. Now before you jump on me for using STP the original product had directions for adding to any oil fluid in the car which we did routinely with no problems. It even slowed (but did not eliminate) leaks and slippage in dynaflows.<BR>Willie<p>[ 08-17-2001: Message edited by: old-tank ]

[Jyrki]

STP is nothing but a plastic polymer thickener, as those used in all multivis petroleum motor oils, so no harm done. It does nothing to lubricate, though, just thickens the oil at higher temps. The point is, you don't need these thickeners with synthetics.

[The Old Guy]

I thank you gentlemen for this post!! I have had an ongoing problem with my 455 powered 37 Buick because of the steering. it has a Mustang 2 rack with a GM steering pump,and the steering felt like it had a catch in it.After reading this post ,I went out ,drained the system and put in Valvoline power steering fluid and now it steers like it should. <P> THANK YOU

[old-tank]

Ken<BR>See my previous post in this thread (8-17)...then go to ebay...55 buick and you will see a high pressure hose; I bought and installed one of these and NO MORE NOISE!<BR>Willie

[KAD36]

Thanks Wille- I had my eye on them puppies. There was one up there that you bend to get the fitting right then another one that looked NOS, no bends required. I was dubious if the rubber would really be in good shape after all those years - don't you think it would be a little brittle and cracked? The pressure hose I have on the car now is not a 2 section piece like the one I took off ( and saved for a spare) - in fact, I haven't been able to find a hyd. hose house that can make one that way without putting another flare and coupling in the middle. I'm still in the hunt - does Buick Specialists make an "original" style pressure hose?<P>Switching from Dexron III to GM PS fluid quieted the unit down, but it still isn't as quiet as it was with the original "2 piece" pressure hose and Type A fluid. This was definitly a learning experience.<P>BTW - getting lazy on the steering gear installation. Sealed up the cover plate leak with your idea, painted it up with Eastwood cast iron grey paint, hooked up the horn button. It holds oil good and is the best looking doorstop I have in the garage - definitely the envy of my neighbors. Will have to fire up the kerosene heater one of these weekends (used up the warm weekend putting decorations on the house), heat up the garage and just get this over with!<p>[ 11-26-2001: Message edited by: KAD36 ]

[Guest 70 Electra]

I'm jumping in late, but felt compelled to offer some facts that both support and refute comments/allegations from above.<P>NTX5467 is right on. Dex III is acceptable where Type A ATF is specified. Use it on all GM automatic transmissions.<P>Jryki is mistaken in his comment that DexIII is "thinner than any previous ATF". In fact, Dex III has similar viscosity to its predecessors, DexII, Dexron, and Type A fluid. DexIII does, however, have better LOW temperature viscosity characteristics to enhance its ability to flow through the small orifices of electronic transmissions during COLD weather.<P>Both "genuine" power steering fluid and ATF have viscosities of around 7-8 centistokes (at 100C). As a reference, an SAE 30 motor oil is about 10 centistokes. ATF is about the viscosity of a SAE 20 motor oil.<P>The reason ATF and PS fluid have some differences is that both hydraulic fluids have evolved for different purposes over the years. Additives are slightly different, but in general, the ATF should be fine for most power steering applications.<P>As for DexIII (or any other ATF) causing problems with Viton seals, that's hogwash. Viton seals are used in transmission applications as well as P/S applications and therefore compatability is a must for either fluid. <P>The whining or other noises that were observed after using DexIII are most likely due to trapped air in the system, which is frequently a problem when servicing the system. It is NOT due to the DexIII.<P>If you want to get "real" power steering fluid, and don't want to pay Mr. Goodwrench, buy Texaco. The Texaco P/S fluid is what is currently used as GM factory fill. (Believe me, I know! wink, wink ) There's no need to turn to "off brand" or private label products of questionable formulation or quality.

[old-tank]

Ken<BR>I used the bendable variety that is being advertized now...no big deal and now I have an extra tool to stumble over. Actually I have never had a leak on an original hose...just changed because they were ugly and worrisome. The one piece tube is now a spare to carry with the other parts and tools.<BR>Willie

[KAD36]

Greg<P>Thanks for posting the specifics on Dex 3 and PS fluid. The Texaco PS hint is a good one and I'll take you up on it! <P>I agree the information you state on viscosities would appear to make a negligible difference in operation, but before I changed anything in my car, I always ran an original NOS style 2 piece pressure hose with true Type A fluid in the PS pump (Wolfs Head brand to be exact) for the past 18 years I have owned the car. No problems ever. I have always run Dex 2 and now Dex 3 in my Dynaflow without problems also.<BR> <BR>In my specific case, with whatever tolerances, wear or other variables that are specific to my PS gear and pump, changing the fluid type made a big difference. I am dead positive of it. Changing back to a 2 piece NOS style pressure hose also reduced the hydraulic noise even further. The noise I have only occurs while driving and putting the car into a turn when the force on the wheel is enough to require power assist.<P>I have flushed the system a number of times over the years with Type A without these problems. I was aware that all the Dex's and Type A were interchangable (at least for transmissions). Thats why I was so stumped after this job! <P>Now, in the middle of all this, after that first drive with the Dex 3 in it, my PS rack sprung a major leak, continues to do so, and it was bone dry before this. No "miracle in a can" has fixed it or slowed it down, which to me implies a catastrophic failure of an internal seal in the power rack, although I still have power assist. Common sense tells me that Dex 3 wouldnt eat seals in 30 miles of driving. If it was just time for this PS unit to blow a gasket, I guess its coincidental with putting Dex 3 in it.<P>Bottom line - from here on out I will run a 2 peice pressure hose and switch to Texaco PS fluid after I use up my GM supply - this seems to give the quietest operation on my car. I have a "newer" PS gear waiting to go in .... very soon!<p>[ 11-29-2001: Message edited by: KAD36 ]