TheoJ

Hi all,
my 928GTS had an oily stain resulting from where the hoses on the steering reservoir are connected. The old hoses seem more or less ok, not brittle or so, but ATF was seeping through I guess. I decided to fix that issue and share this with you.

A first thought was to cut the upper bit off from the hose, reattach, and see if that would fix it, but I decided to do it properly and use two new hoses.

There are two hoses involved:
1. The feeding hose from the steering fluid reservoir to the pump. This is hose # 928.347.445.06. It is kind a special, the pump side is 12mm ID and the reservoir side is 15mm. Yes, 15mm at the reservoir side (who designed this....). It has three turns in 2D and the 15mm side goes up 45 degree as well (hard to see on the pictures), so I decided to buy that one from Porsche. I first removed all ATF from the reservoir with a big syringe. With some skill you can now remove the hose at the pump side without lowering the alternator. Just cover the alternator with some plastic bag to avoid remaining fluid entering the rear of the alternator. If you have big hands and thick arms... you'd better take the alternator off I plugged the 15mm side with some cloth to avoid dirt entering the hose while manouvering it into place.



2. The second hose is the return hose from the cooling pipes to the reservoir. The hose is clamped on to the pipes and is considered an integral part of the assembly. With a cutting disk on the dremel it is not so hard to get the hose clamp off, remove the short hose and keep the ATF cooling pipes in place. You will know when you finished Dremel-cutting when the rubber starts to smoke It takes a short 12mm ID hose to connect to the reservoir. I chose Nitrile rubber as this has very good resistance to ATF additives in the steering fluid and hopefully will never leak anymore. Use a proper clamp to fit the hose to the pipes.

I carefully cleaned the reservoir internals with a solvent, and was also amazed about the amount of residue I found inside. You might consider replacing the reservoir as it has sort of a filter inside and cleaning the filter is a job of patience and rinsing
http://jenniskens.livedsl.nl/Technic.../MyTip1027.htm

Next is fill up the ATF, start the engine, turn the steering wheel completely left and right a few times and add more ATF. Do some testdriving and check ATF level again. Air bubbles should have gone now and steering should not make any funny noises or so. Check for leaks for a few days.

Here is a picture of the two old hoses (linked from my website):


regards
Theo Jenniskens
1992 928GTS Midnight Blue
The Netherlands

Randy V

Good job on the hose replacement.

That fluid reservoir should be replaced as standard maintenance as it contains a filter that can't be properly cleaned.

They are relatively inexpensive - around $30.

ROG100

Most buy 2 x 928 347 445 06 and cut a section from the second hose to repair the short section on the return to the reservoir.
The reservoir is a consumable and should be changed and as it only costs about $20 an easy decision.

TheoJ

Well.... if I had a new reservoir I would have replaced it. I was not planning on a delay in the job by ordering a new reservoir, so I decided to clean it. I'd however recommend to buy a new one while ordering parts.

Like you say: the reservoir is not expensive. You can't replace the filter element inside, sort of a porous stone like material under the metal plate that you see at the bottom of the reservoir. But it can definitely be rinsed by reversing the flow. It is clean now.

@Roger: cutting a part of the second hose is certainly an option. Nitrile rubber is however the best choice for this and very inexpensive. I would have used this Nitrile rubber hose for both connections if the feeding hose was not so "kinky". Anyway, it hopefully lasts for another 22 years

regards,
Theo
1992 928GTS midnight blue