james944

HardTarget,

I don't think that the problem is with all synthetic fluids. In fact Porsche recommends we use Pentosin (as per http://www.pcarworkshop.com/images/3...0696geolab.pdf ) and Pentosin is a synthetic fluid (see: http://www.Pentosin.com/flexxtrader/...F%2011S_GB.pdf ).

It is only that some synthetic fluids are not compatible with the seals in our power steering system. My understanding was that if you used the wrong type of fluid, you would know it, because the seals dissolve very quickly.

That being said, I'm starting to get nervous about this too, and will probably flush and refill my system with Pentosin when I change my oil in a couple of weeks.

Hope this helps,
James

Laker

Well here is a new data point. About the third thing I did after getting the C4 was to flush the power steering fluid-
I used the drain-fill lock-to-lock turn repeat 5 times method from here: excellent write-up btw.
https://rennlist.com/forums/964-1989...ing-fluid.html

The old fluid was black... bottom of the coffee urn black.
Following the owner's manual and Adrian's book's advice, I steered clear (sorry) of any Dexron IV or anything that said synthetic. I chose Valvoline DEX/MERC ATF because it says DEXRON III right? It does not say IV or synthetic.

Well now I have a leak. I have driven maybe 150 miles. Not a all-seals-gave-out flood, but a couple of drops per day coming from (hopefully a reservoir return hose) or maybe the pump itself. Looks like my car is bleeding :-( The fluid level is still perfect in the reservoir?

Update, so I'm setting a trap for the fluid... new paper towels

Makmov

I am pretty sure that is what I used. Valvoline Dex. It didn't say II, III, IV it just said for all Dex/Merc vehicles.

jimq

tighten the clamps on the short hose first. That worked on mine for a while but it began to weep from the hose it self a year or so later so I replaced it. Right after that my rack started leaking

campoj2

I have also heard that if you use DOT 5 brake fluid in a DOT 3 system you will have a problem with leaks. Has anyone else ever heard of this?

Laker

Thank you Jimq. You were right on the money
Steering Pump to reservoir hose 964-347-445-03 ($12.50 @ Pelican)

The screw clamp on the pump was already cranked down 100%, the single use ribbon clamp on the reservoir that took me 30 minutes to get off, well don't get me started. Who invented these torture devices anyway?

I am so relieved it was this simple (for now) and I don't have an oil leak. I probably never considered the wetness could be Dex III since it was black.

I want to apologize to the fine folks at Valvoline. Will the hired goons in the black sedan with Texas plates at the end of my street please go home now?

nvrlft

FWIW, I concur with the Valvoline DEX/MERC. I have used the Castrol equivalent with no apparent repercussions. I have been doing the pump the reservoir/refill/turn the wheel method at oil change intervals.

Grazie

Quick check-in on this topic as I just got home from the store with the same ATF Laker used here (Valvoline Dex/Merc, blue bottle). Any updates on issues or others that can confirm they've used this same fluid with no adverse effect?
I'm about to change it out and some it-work-for-me piece of mind would be great.
Thanks in advance.
Cheers,
ATC

Laker

No issues with Valvoline Dex/Merc. The 'leak' was already there. I didn't notice it because the old fluid was black, and I thought it was old oil. The fresh fluid was red and really stood out. It was a PS pump seal and hose as noted above.

FineProperty

After a google search turned this thread up in the top results, I thought I'd revive it. This is on my to do list now, the ps fluid is dark and slightly low, no issues driving though, and no leaks, but I don't know what's in there to top it off.

RicardoD

I used valvoline dex/merc in blue bottle as this. This is also my Tip fluid