It was about 22f this morning when I started my car, the power steering pump or rack was groaning and it didn't stop until it warmed up. The fluid is was flushed about 3 months ago, nice new sythetic power steering fluid. I checked the reservoir, there was plenty of fluid but it was foamy, I turned the steering lock to lock a couple times. So whats goin' on? Is it just too cold for the poor little 16 year old pump?

 

My 1984 944 takes automatic transmission fluid (Dexron II) for the power steering not power steering fluid. Check the specs on the 951 and see if you should use ATF.

Also, there is a filter in the reservoir. If that filter gets clogged, cold fluid that is running thickly won't make it through the filter. The PS pump will cavitate. As far as I can tell the only way to change the filter is to replace the entire reservoir.

 

I believe you should use Dextron II or III ATF, not synthetic. There was a thread a while ago saying to stay away from Synthetic fluids for the ps system...

I added some Castrol Dextron III ATF to my gf's car which had the same exact symptoms, and so far so good. Can you believe Lexus wants $130+ for a ps reservoir????!! I wonder if one of our reservoirs can fit her car?

 

My pump made a groaning noise on my '86 951 for a bit, and had the same foaming problem. On mine, it turned out that the belt adjuster had broken and the pump was loose. Installed a new adjuster and the problem went away.

I am not sure about the synthetic power steering fluid... I have always used ATF in my cars, and I don't have any problems, aside from the low pressure hoses, which tend to go bad from what I can tell (I have had to replace that hose on all three of my cars).

Regards, ...Scott

 

Thanks for the reply's, yeah I wondered if the synthetic was the problem. Sometime I'll slap some ATF in there, did't really think twice when I put the power steering fluid in. I replaced one hose that was dangerously close to the ps belt, it had rubbed against the belt for some time.

sm: i've seen that reservoir in so many cars, tvr uses it in their tuscan, and i've seen it in a few exotics. It must be "the" european power steering reservoir.

 

I think I would flush that synthetic PS fluid out sooner rather than later. Like in the next hour!

I was told that it will attack the rubber seals and I know Thad lost his rack to leaking within days of making that mistake. Better safe than sorry.

 

Yeah, they say use Dextron III for a reason! Also, make sure none of your belts are crimped... but I'm guessing it's the fluid.

-Matt

 

I just defiled a turkey baster, I'll drive the car some today and keep rotating the STP ps fluid out with Dextron ATF. The ps fluid I had in there was pretty damn thick, and after checking the bottle it wasn't synthetic, just regular old PS fluid so I'm hoping it didn't turn the seals into mush!

 

We just had foaming due to inlet restriction causing pump cavitation (sucks a vacuum = bubbles)

I cleaned the reservoir (off the car) using a solvent and backflushing, using compressed air too. Also used LPS #1 as a cleaning agent before reassebly.

The inlet pipe had kinked and was restricted - fixed that too.

An increase in viscosity, such as using Lucas which I did, aggravates the pump supply issue. However if the pump is well supplied, Lucas will boost pressures and improve steering performance.

Paul Jager
www.jageng/com/944S.htm

 

A similar thing here. One of my steering pump mounting nuts decided to take a hike leaving the pump and belt loose. Groaning and foaming were the symptoms. My return line from the reservoir was also shot.

 

Oh shoot!
Here's the problem of an over-eager kids. My son heard a "noise" from the PS. He added regular PS fluid to it. Subsequently, it's been leaking (pump or rack, don't know). And it GROANS when cold, just like Type_LT described.

So - looks like I should do a full R&R on both the pump and rack by replacing all the seals. What else should I replace. Yes, I'm thinking of replacing the reservoir just because it's from 1987. Hoses?

btw - I really can't blame my son, as I probably would of been clueless as well to ATF vs PS fluid.

 

I replaced my pump when it was moaning for about a month, and then threw up all the ATF through the reservoir...the new pump and fluid made it good as new.

Steve