Still smooth and quiet.

Most people I know bailed-out on thin Pentosin CHF 11-S a
long time ago. MB developed +4 as an awesome ATF, which doubles as PSF. GM likewise uses their Dex 6....duty tested.

ATF is the most common ps fluid in the industry. VW, et al, used Dexron 2 and 3 before CHF, using the same ps parts, like MB uses the same parts as VAG.

Anyway, I know Porsche owners have failure issues, just like other Euros, except MB. So, I thought I'd point it out as a easy solution. As psf temps rise, the fluid thins, CHF is already thin, so the pump has metal contact, producing runaway heating...and warping the seals. ATF has a slight seal swelling effect too, so it really is ideal. Thicker with more and better additives is the key. Many people used Mobil 1 ATF in the past. Its a fine choice now as well.

I just used a turkey baster, its easy. Small reservior means a bunch of fill-run-empty cycles are needed for this car. One quart should do it fine.

I'll post some data later.

 

Your recommendation to switch from Pentosin to ATF for power steering fluid is uncalled for and wrong given the steering system is a safety critical system.

You apparently believe to know more about the power steering system and its internals and its ability to work properly and safely with an unapproved fluid than Porsche.

Porsche doesn't even have a power steering fluid change schedule and yet you advise not only this fluid be changed but changed and replaced with a fluid that is not even approved for use in this hydraulic system.

It is bad enough to read all the goofy ill-advised engine oils, transmission fluids, coolant fluid recommendations from self-appointed experts on these systems/assemblies and their fluid needs but I can't sit quietly by and let safety critical systems be compromised by dangerous fluid fill recommendations based on no more science than essentially "I did it and nothing blowed up."

As for power steering fluid changes, since my Boxster has over 260K miles on its original power steering system and original *Pentosin* fluid (which in an aside strongly suggests that if there is any issue with Porsche power steering systems it is no due to fluid, Pentosin, used in them), I spoke to some senior Porsche techs a while back about power steering fluid changes.

I pointed out to these techs -- though they are well aware of my car since they have serviced it now for a number of years -- that given it has so many miles what about a power fluid change? Should I change the fluid, have them change the fluid?

I was told no. They see no problems related to power steering fluid issues directly and a fluid change is a real chore given there is no provision made for draining the system. (Which should give us a clue there is no reason to change the fluid.)

Understand that I was not asking for a freebie power steering fluid change and was facing $150/hour labor charge (for I do not know how much time was involved) along with God only knows how much Pentsoin fluid. And yet the techs advised me there is no need to change the fluid. Even for apparently a car with 11 year old fluid still in its power steering system.

The techs went on to describe the process (even though I was familiar with the process): The fluid has to be siphoned out of the power steering reservoir -- but not so low as to risk getting air in the system. Fresh fluid is added then the engine is started and the power steering pump runs and the new fluid is mixed with the old fluid. The engine is shut off and the reservoir fluid level siphoned down again and this process repeated several more times -- with the steering wheel cranked from lock to lock several times with the engine (and power steering pump) running to ensure any fluid in the rack is cycled back into the fluid flowing through the rack -- until the color of the fluid in the reservoir indicates there is so little of the old fluid remaining to be unworthy of further fluid changing. The techs suggested the amount of fresh fluid necessary to get the fluid replaced would be considerably more than the fluid capacity of the power steering system. They did not tell me how much fluid would be requied but there is the reservoir but also the lines and the rack too, all are full of fluid.

And I note the above is based upon using the same fluid that was in the power steering hydraulic system.

By using ATF you can't tell how much old fluid is present and thus your "One quart should do it fine" recommendation is simply a guess.

It is your car and you can roll the dice, play Russian Roulette with your car's safety critical systems all you want.

However, I'll leave my car's safety critical systems and their fluid needs in the hands of those that know what they are doing: Porsche and the techs trained to work on these cars.

 

The reason you "think" any other fluids are "unacceptable" is because you have no experience nor confidence in your OWN knowledge.

Time and again, you're all butthurt because you want to be the **** or parrot of the forum who polices everyone by crowing that anyone associated with Porsche, Pentosin or whatever automatically knows everything. The thing is, YOU don't know, and THEY don't know....even close as much as I do.

All you seem to be able to do is make broad assertions based on generalities and false conclusions. Why not attempt to analyse the technical aspects, and see if you can learn enough to waddle thru a real discussion.

The fact is, you don't know squat, someone who "never heard of a blown PS system.." lol, try the big boy forums, where they're not driving like a putz. See how many times people rebuild systems and add coolers....blah blah. Clueless....you.

Not servicing your PS system is a really dumb move, rooted in some offhand comment from a tech who was sick of talking to you. lol again.

So, you never serviced a PS system, never tried other fluids, never "heard" of blown systems, have no idea what other mfgs use and why, really don't know or understand the fluids involved....but YOU are the expert. lol.

 

Maybe an expert can explain the failure mode of a fluid that is fractionally thicker when overheated. How is this going to cause catastrophic failure?




Should't fluid that's a hair thicker be, umm....better?

I can tell you how old Pentosin can fail, a thin fluid sheared to a superthin state and contaminated by shed metallics from the pump and blackened from seal degradation...it causes friction, heat and wear...simple.

I'd ask, why not test your theory by sending in a sample of your fluid to someone who can do a PQ Index for you (look it up)...Butler Caterpillar labs maybe.

Your blind devotion to the owner's manual has failed you time and again. Coolant, oil and now, PSF. Guess what, lube tech changes and improves over time. So does knowledge and information, despite the effort of duds like you.

Let me get your tortured logic strait again...NOT changing your PSF is "safer" mechanically and literally? lol.

 

I guess you never heard of a leaking PS system either....?!

omg.

 

Audi Junkie, you're out of line and crossing into absurd and hysterical.

PS leaks and PS pump failures in pre-987.2 cars are from tracking hard in hot weather. Not really relevant to street cars. Yes, they can leak and fail just like any system in any car ever made, but very rare unless flogging it on the track.

 

I've never changed PS fluid on any car I've ever owned, many with over 150K miles, Porsches included. I've never had a failure, no leaks. I know no one who has ever changed PS fluid.

Just saying.

Interesting exchange...

 

There is no "exchange", just a scared boy who seeks the black-and-white approval vested in the "owners manual", and a man who sees beyond the trifle of decades-old manuals.

Clinically, it's a chronic case of "fear of the unknown" and the accompanying "deference to authority".

In practice, one guys says we just don't read or understand the owner's manual, and will refill his leaky-dry system over and again with CHF, rather than have the knowledge (and *****) to apply a better, newer fluid to the problem.

Remember people, no auto mfg has ever made an error nor decision that doesn't have the customer's best interest in mind. (insert sarcasm)

So, who had the best info, someone who has no experience with the subject, or someone who has LOTS of hands-on experience with a vast lube background....hmm.

This ATF+4 has been in for <5 years, in a old Honda....you know, another brand that takes "special" fluid, or it will explode!




I'm too lazy and idc enough to search out the dozens of stories, from people I know, where ATF cured PS leaks, made systems run quieter and last longer. Never had a ATF/PSF fail after the owner switched either. This is going on 10 years+.

So, who has useful info, the guy who extrapolates, seeks negative "proof", has claimed no real experience....have you ever even written on the subject before Macasster? It's easier to just troll posts that you don't understand and cite the all-powerful "manual". lol, if they told you to jump off a bridge....lol.

His childish fear of the unknown already bit him in the *** when he decried that, not only are non-Porsche coolants different from others, they are COMPLETELY incompatible and will cause death and destruction....so says a tech who would rather talk to mcass than work a $100/hr job.

In reality, the Porsche coolant didn't turn out to be so special, just $9 generic Dexcool.



Don't let fear of the unknown keep you from using your own intellect.

"Most people would rather teach things they've been taught than go and do research on something new. [36]"

 

After spending 10 minutes reading it seems like the conclusion is pretty simple and doesn't need pages of pointed writing to get there:

1) On most cars it is unnecessary ever to touch the power steering fluid.

2) Should the need or desire to change the power steering fluid arise, the Porsche fluid works fine, but there are other non-Porsche recommended fluids which may also be fine. [It sounds like doing the change is a PITA and takes time and expertise, which is why it's probably not economically worthwhile and thus not recommended.]

3) Those with sufficient knowledge or willing to do the research can weigh the alternatives. Others can just go with the manufacturer's recommendations.

In my experience, conclusions 2 and 3 also hold for washer fluid, engine oil etc...

 

Ill assert that PSF should be changed. After reading and replying to several threads on the 911 forums, where blown PS systems are the norm, I hastily inferred 986/7 owners would like to take this simple step to assure a long lifespan of their systems.

The high temps and number of shear strokes in the PS system will reduce the fluid viscosity, below the already thin 6cSt. Contaminates accrue, and the additives in the fluid wear out, that being the friction modifiers, anti-oxidants, detergent and dispersants etc. Lubricating a PS pump is demanding on the fluid.

Many vehicles fall to PS problems, it's true. idk what people think the failure mode is, but weak fluid is the most obvious.

Changing is very easy with the turkey baster method. Like I said, the reservior is small on the Boxster, so it takes quite a few cycles of extracting and refilling, and then running the engine while turning the steering wheel a bit.

Easy, effective and cheap. idk what's not to like. You can refresh the system with CHF11S, but that's kind of a sideways move.

 

I never claimed to be an expert on power steering fluid selection. I have not had to be for any number of other brands of cars I have owned so why I should have to become an expert on power steering fluids with my Porsches is beyond me.

You self-appointed experts and your horrible advise based on no more science that "hey try this what can it hurt?" would be an embarrassment to anyone with any sense.

Besides, I already have a real expert's input on what is appropriate for my Porsche power steering fluid. Porsche.

But you dismiss this.

You somehow got it into your head you possess knowledge that apparently the engineers/designers at Porsche don't have access to and thus you can appear to be all knowing about all fluids for Porsches. At least to the dead. Any sentient being would dismiss your blathering in an instant.

I know I do. I wouldn't take your advise on what lubricant to use on my roller skate bearings let alone any of the safety critical systems on my Porsches. Uh, make that systems on my Porsches for which I care.

 

get it back on topic and off of personal attacks or this thread will be closed

 

Like I said, this is the type of tortured logic you expel when you have no confidence in your own analytical abilities.

Too bad so many amatur Porsche owners have such a stick-up-the-butt mentality. Most other marques I deal with, the owners are anxious to apply their own wit and will, rather than worrying about "The Book".

For instance, my wife's Opel Astra. In Europe, the modest 1.8 VVT calls for 5w-40 ~synthetic~. When Saturn sold the same car here in the US, it's 5w-30 dino, right on the cap.
So I ask, which is "correct" Which advisement does the "smart" owner go by? My answer... 5w-20.

Doh, do they even have 5w-20 in Europe? Nope. Is 5w-20 advantageous in winter when my wife takes her 3 mile commute to work? Yep, 5w-40 would be like pancake syrup. Same thing goes for the MTF, spec in Europe is 75w-90 GL-4, but spec in the US for service refill is GM Transaxle (thin ATF). What did I use in it? Midweight Syncromesh, the best specialized MTF to come down the pike. Way thinner than 75w-90, and dirt cheap. Sort of like a Asian MTF. Oh, any idea what VW MTF is now? It's thinner than ATF, which is insane. dyk what the VW SERVICE manual says to do if the customer complains of a noisy trans....switch to a old thick 75w-90 GL4. Kind of funny, I mean...wouldn't the trans explode if something other than the one ordained gear oil wasn't used?! It's good to know wtf is going on with other marques, eh?

Another interesting aspect of the German GM service schedule is that fact the OE MTF is factory-fill is lifetime...or is it? On standard models, it is "lifetime", but on VXR models, a single MTF change at 6000 miles is specified. How can this be? What's "right"? What should a guy like me do, I have a standard model, but changing the fluid is no big deal for me. I have the tools and skill as well as a premium fluid to replace the OE fill, one suited to my driving cycle and climate. Just like a PSF service, I'd be dumb not to change that ish out.

If I lived at the Arctic Circle, I'd stick with CHF-11S, it's a very high grade of aircraft hydrolic fluid. iirc, it even has some MIL-Spec rating for such. In a hot street car with some hoon driving, it's a skip. Seriously, just the fact that Mercedes developed ATF+4 and uses it would be enough for most people here w/a brain to accept it as a ~possible~ PSF fluid, for Porsche or WHATEVER.

Please remember people, not every fluid is evaluated by every mfg, whereas (insert auto brand) selects ONLY the best. It just doesn't work that way. Factory certs are a business, $300k for 3 years w/VAG 502. The same fluid covers almost every brand. imo, GM-LL025-A is amazing, but some generic ACEA A5 oils from WalMart cover it handily. Off topic, but the best starting point is Lubrizol's Relative Performance Tool



http://origin-qps.onstreammedia.com/.../pc/index.html

While you're there, compare generic and mfg specs.

dy think Porsche is going to use a Mercedes PSF fluid?

I seriously thought that, on a Porsche Forum, that you guys would already be onto the Mobil 1 ATF as PSF tip. I have no problem with that, but ATF+4 comes with a reference page in the "Mercedes Book". Generic +4 is dirt cheap, like $4 W*M Supertec...because it's not generic, it's proprietary....a specified base oil and exclusive Lubrizol additive pack. Same **** as $15 a bottle MB PSF/ATF over-the counter.

Really, it's kind of a laff arguing with thin air, but I always assume there are readers who want the full story, and appreciate my effort, even thru the static.

Let me condense and simplify so nobody gets all butthurt over the syntax. If you want to change your PSF, and I think you should, OR if you have a leaking system, you CAN try the newer and better MB ATF+4, which is a lil thicker, with more and better additives as well as a slight seal-swelling effect...with a simple technique. Or you can ignore it and hope for the laws of physics, chemistry, experience and logic do not conspire against you.

Now, a trivia question. What did Porsche+Audi and VW use as PSF *before* CHF-11s?

 

Ok, like I said...thread closed....perhaps it would be helpful if you could provide your superior knowledge in a less condescending manner that doesn't make you appear to just be a troll