Macster

The problem I have is AJ assumes that viscosity at high temperature is all that matters and that the higher the temperature and the higher the viscosity the better.

But remember this fluid also is used to operate a steering rack. I could imagine the drop off in viscosity deliberate to in some way modulate/dampen in some way tone down the steering's response at high speed.

(Have to mention that chemically ATF and Pentosin are different and one has to be concerned about seal/gasket compatibility if one switches from running the factory fluid -- Pentosin in this case -- to ATF.)

But back to viscosity: Here's part of the problem. Someone says "thicker is better" and is not required to give any justification but to drag out some tired old viscosity vs. temperature chart and point to that.

But if anyone brings out, quotes from, a Porsche factory service manual or points to some label on a cap or a warning sticker which states which fluid to use this info is clearly suspect and can be questioned without any need to offer more than the aforementioned tired old viscosity/temperature chart.

Last but not least, can anyone in full possession of his facilities believe that power steering pumps are so much more profitable to sell than cars?

To believe Porsche specified Pentosin to ensure early/premature power steering system failures to improve its bottom line at the parts counter is simply ludicrous.

AFAIK, Porsche doesn't even make its own power steering pumps, so it would be helping enrich a supplier. How thoughtful of Porsche. Always looking out for its suppliers at the cost of its car buyers.

I mean auto companies that by accident have managed to introduce problems that have in a few cases led to accidents with injury and even death have been called on the carpet by regulatory agencies and faced severe financial penalties. Toyota apparently paid over a $1B fine because some owners couldn't tell the difference between the accelerator pedal and the brake pedal.

And AJ would have us believe Porsche is willing specify the wrong fluid in the hopes a power steering pump failure occurs which since this is a safety critical system would have to put not only property but people at risk, and God forbid something horrible happened, put to risk all the company had become, put to risk its very existence, for the potential profit it (oh and that every important pump supplier) might obtain by selling a handful of owners a new power steering pump, assuming that when the pump goes bad they do not go to the aftermarket for their pump needs.

Audi Junkie

Right, because it's low temperature operation that increases wear, runaway metal on metal friction and warps seals....not high temp. (insert sarcasm for dummies) Sorry if I assumed you understood that a more viscous fluid would prevent that.

Instead, let's focus on my humorous anecdote about designed obsolescence. There's a nice easy subject for you to pick apart.

lol.

Audi Junkie

ATF+4 has the highest level of friction modifiers of any PSF, that's why I gravitate to it vs Dexron VI, Merc V, et al.

It's also a proprietary formula, specifying a certain base oil and Lubrizol additive package for the license. You know what you're getting, no matter which brand is on the label. It also has excellent low temp qualities.

Good question.

Audi Junkie

Year three, still going strong, lol.

Macster

Year 13 with my 2002 Boxster and still going strong and now up to 291K miles. With the original power steering fluid fill no less.

My 2003 Turbo power steering (and clutch) system is just fine as well, 12 years going and with over 135K miles.

ATF in the power steering system is yet another "fix" in search of a problem.

Audi Junkie

You must be driving like a granny. Def you should alert Porsche that used 13 year-old PSF is superior to fresh new fluid. You've already sent a sample to the lab, right? Since now, it's fully oxidized, contaminated, sheared down and additives like friction modifiers are all worn out, all that's left for you is failtime.

Nice try at deflecting the subject, which is: will MY system fail because I used a poison ATF?! I do not fing think so buddy.

Poor maintenance is nothing to be proud of, but the hard-head of ignorance prevents you from basic analysis of the system. You're telling people to never flush their PSF (although most people with a brain already do it). Don't test it, don't even consider the fact there may *now* be better fluids out there.....ignorance is bliss. (is bliss the right word?)

GVA-SFO

I think fluids are a little bit like vines : the taste, ..or the brand, or the name, makes some preferring one or another.
Also, there are cheap vines, full of chemicals that can make you sick, and some that are quite healthy, having "good" components inside.

The problem that I feel with the Boxster (having only around 3'000 miles with mine, 30% of that being track miles) is that power steering is not well designed.

For example, mine leaks currently.
Refilling, leaks, off the dip stick, refilling, etc..
I had 30 years non stop of 911 before this Boxster, ..and never had any steering pump problem. It is true that many of my earlier 911 ..had no steering wheel pumps!!

OK, what are the solutions ?
I have on stock a smaller main pulley, ..but did not installed it, as I felt that this going to reduce the flow of my water pump, and, ..increase potential temp. (even, having already new water pump and new low temp thermostat).
Shall I still go to install my smaller main pulley ? Not sure of that.
Or, should I go "electric", everything in the front, and remove the long pressure pipes, remove the current pump (fitting a non functional simple pulley instead). This one is is a US$ 1'600.00 question !
Or, should I “simply” replace the current pump ??
But, frankly, I do not care about the type of fluids, thing, that I could add, is NOT the case, if I’m talking about the brake fluid, as there, the best quality is IMO ..a must !
(I just hate brake fluids that make bubbles.)

I do not know yet what to do, but, I have to do something, as I'm tired with my PS leak !
..That seems to be a "typical" Boxster problem.

Audi Junkie

I know, with adding Pentosin to a system that simply CHUGS it, talk of decade-old PSF is inaccurate. We can dismiss claims based on it, to the point I'll be happy to send my old fluid to whomever would like to use it.

ATF+4 has a slight seal-swelling property, adding to the positive effect it has on "leaking" systems.

Macster

So the fluid is shot? And yet the system continues to operate just fine.

What poor maintenance? There is no power steering fluid change schedule. If someone wants to replace his car's power steering system fluid in the belief it will be of some benefit that's his call not mine.

What I can't in any way condone is the use of anything but the fluid Porsche specifies.

I'm certainly not afraid to spend money on maintenance to help ensure my cars last but nothing I've learned over the years since I have owned my first car suggests a power steering fluid change is required.

You again grasp at straws to in some way justify your switch to ATF.

Furthermore, I dare say your car's power steering system's continued operation with ATF speaks more to the margin in the steering hardware than -- in your mind at least -- the belief in the superiority of ATF over the Porsche fluid.

Look at it another way. Your opinion is the fluid in my system is past it. If so then how much of a role can any fluid play if the fluid in my car's power steering system is way past it -- your opinion -- and yet the power steering system still works just fine?

Macster

Well, your system is in the minority. Most owners do not experience any problems.

Those that do mostly appear to be those who track their cars. A power steering fluid cooler is probably the best thing you can do for your car's power steering system. I would not fit an under drive pulley to slow down the power steering pump. To run the water pump slower to possibly benefit the power steering pump is risking the engine for the sake of the pump.

An electric setup seems expensive when a number of owners have managed quite nicely with the stock system.

My advice would be to address the leaks. The system carries very high pressure fluid -- I seem to recall around 1000PSI -- and the fittings and seals must be in good condition.

In some cases a high pressure bypass valve can fail and supply too high of pressure of fluid to the system. This can have fluid forced out the rack seals -- it can take some time as the dust boots capture the fluid for a while. If the rack seals are leaking you need to consider replacing the suspected high pressure bypass valve and replacing the rack seals if they continue to leak.

In the case of your car, while the high pressure bypass valve might not have failed completely it might not be working right and the system could be simply overpressured. It might be of some value if possible to check the pressure to see if it is within range. Maybe even explore fitting an adjustable pressure bypass valve and dial down the pressure.

As an aside, I do not know about the Boxster power steering but the Turbo power steering has quick disconnect fittings and these often get damaged because the person who works on the system does not know how to properly disconnect them and then when the damaged fittings leak they get the blame when it is was the ham-fisted human that did the damage.

GVA-SFO

Thanks Macster,
your posts/answers are as usual, i.e.: clever, positive and great quality.

I understand very well that I'm in the "minorities", using a Boxster (S) mostly as a "track toy".

About
"An electric setup seems expensive when a number of owners have managed quite nicely with the stock system." I.e.: "BLT", see :
http://store.biltracingservice.com/b...ring-pump.html
May be yes, for the majorities, but, if I have to consider, a) finding and then fixing the current leak, and then, improving the current system for my use, i.e.: adding a cooler, this will have a cost too !
the other advantage of "going electric", is that the electric pump will be then in the front (as low as possible in my case !) and will enable to remove the "long" (and heavy) high pressure pipes running from the back. Transferring some weight from "center" to front would be (a little) positive !
I think the first goal is to find the exact reason of the leak, which I have not being able to do yet.

I think mentioning the electric system is positive for this topic. (i.e.: "BLT", see :
http://store.biltracingservice.com/b...ring-pump.html
and,
..mentioning (again !) that tracking Boxster's may very well lead to power steering potential problem.

Macster

You are not alone in using an S as a track car. In fact I think the S is favored as obviously it brings more power to the table.

The lines are not heavy and they are located at the lowest point of the car just above the plastic underbody panels in the mini-tunnel that runs the under the car.

I would think the electrical cabling needed to power an electric power steering motor would have to be rather heavy gage wire so what you save by removing the hydraulic lines you add back in with the heavy electrical cabling. Maybe not quite as much weight but close enough.

The electric motor is going to run hot too and I would think would need proper ventilation. If you don't do this you could trade a fluid power steering system with problems for an electric power steering system with problems.

'course, it is up to you. A leaking power fluid system could require some effort and possibly expensive parts to get fluid tight again. And I feel you have sort of talked yourself into electric is better in this context, and you may be right. Regardless, if you believe the electrical setup is the best one given your circumstances then more power (no pun...) to you.

GVA-SFO

well, thinking some more, ..I decided to buy a pump and tank, and, in the mean time will replace my leaky one.
So, let's try to keep it simple and not going electric ..for now !