Mighty Shilling

Guys my Boxster S' power steering pump was screaming this morning. I checked the level and it was low. Where are the common failure points in the system so I can track where it may be leaking from?

Side note: pentosin bottles are evil, and it doesn't taste good at all.

Macster

A pressure relief valve in the high pressure line fails. This routes too high a pressure of fluid to the rack. The rack seals leak but no fluid shows.

Instead the fluid gathers in the dust boots that protect the seals.

The word I get from the techs is by the time the pump makes noise it is too late. New pump. New rack. And a new line with the bad high pressure relief valve.

Check the boots of the rack. Be careful. If I'm right one or both can be full of fluid. I watched a tech check one with a rack on the bench and when he popped the cover loose it literally popped and fluid went gushing out. He had a rag so no one got sprayed with fluid.

Mighty Shilling

Macster, that's not what I wanted to hear. There Is a remanufactured steering rack on pelican for $400 or so. Any idea of the quality of said rack? Will it fulfill my Porsche's needs as well as mine for being a cheapskate?

Mighty Shilling

Can't find that line on Pelican. Know any good sources?

Macster

No idea about the quality of the remanufactured rack. What is the warranty offered with the unit?

As for being a cheapskate aren't we all to some extent or another?

But cheapskates have to be careful. Sometimes the cheapest repair turns out to be the most expensive.

Be aware that if I'm right about what's going on, or what went wrong, you almost certainly need a replacement power steering pump and at least the line with the high pressure relief valve. I seem to recall -- but I may be wrong -- the valve and line are as one and the valve is not replaceable separately.

If the pump has deteriorated any lines reused need to be thoroughly flushed with suitable fluid to remove any particulate matter which would likely damage a replacement pump, the replacement rack, even the high pressure valve.

In fact a concern I would have is the particulate matter could cause the valve to leak and thus feed too high a pressure of fluid to the replacement rack and too soon you are back where you started.

Feel free to visit a dealer service department and pick the brains of a tech who can advise you regarding exactly what he believes based on his experience needs to be replaced, flushed, etc. IOWs, get a 2nd opinion and the 2nd one from a professional Porsche tech.

Do not forget you have to completely refill the power steering system with Pentosin. No air pockets!

Mighty Shilling

I talked with a tech and they confirmed the racks can leak. Said I should replace that first and go from there. Found a place locally that rebuilds axles and steering racks (cvj axles) and I'll have them do it if the rack is what failed. I'll throw that pressure line at it too, and if I can avoid a pump, I will. It wasn't long before I put more fluid in, and it was only loud for 30 seconds or so. Here's to hoping...

Mighty Shilling

Ok so I was able to get some garage time today. Power steering rack is dry as a bone. Looks as if it was a bubble cause probably by boil over from last track day. The top of the engine did have an oily substance under the overflow tube. Just went thru, bled the system, and ensured the level was correct and not over filled.

Also bled the brakes... car is good.

Audi Junkie

Switch to ATF+4 or Mobil 1 ATF.

Mighty Shilling

Um... no. I'll stay with the chf-11s thanks.

Macster

Well, I hope that all that was required to resurrect the steering was addressing a dry rack with a fluid refill and bleed to remove any air.

Keep an eye on the power steering fluid level. I can't help but suspect the rack seals will now be compromised and leak but I hope my suspicion is proved wrong and everything is fine.

gfl

say more - why? Exactly why. I'm leery, but open to fact based learning.....

Grant

Audi Junkie

*bump*

Audi Junkie

Right, because CHF seems to have served you so well.

Kind of tastes like Lime Kool-Aid, I'd imagine.

Meanwhile, I'm at 6000 miles, 6 months on Mercedes' PSF, err...ATF+4, and it's quiet and smooth like butter.

Macster, I thought PS systems never fail? That's what you posted in my thread. Maybe take a minute to go back and correct yourself...?

Mighty Shilling

I'm more of a fan of keeping things as suggested by the manufacturer*. Granted I've modified cars before... But the viscosity of power steering fluid is not so much in my bag of tricks. I know nothing about it, and since I only go thru it at the track, I just grab a can of chf 11S for my track day and check the level after I run. Street driving it doesn't use a drop. I don't really care to research it, as I don't find it to be a problem now that I know what to look for.

Audi Junkie

What I'm suggesting is the fluid IS a weak point. You're looking for a hard part solution, when things can be MUCH more simple. This issue isn't specific to Porsche, VAG and BMW use the ultra thin CHF, with poor results. MB looked to their own amazing ATF+4, as ATF is a the most common PSF industry wide. It's only $2/q and a proprietary formula, duty-tested for PSF use and has a little page in Mercedes spec book. Clearly a case where more cost certainly isn't better.

What do you think these mfgs used before CHF....? Oh, wait...you don't care to research it, so nevermind. My vast experience in this area is disregarded, I'm sure there is an axiom for it too, but proceed right off the cliff....if the manual says so.