Power steering fluid level check?

[deilenberger]

Is it done engine running (like most euro cars) or engine off?

Reason I ask - if the truck is stationary and I got lock to lock, there is a shudder in the steering wheel when it reaches close to lock.. the truck has Servotronic.. I watched the actual wheels, and there is a slight shudder in them corresponding to the shudder in the steering wheel. It sorta looks like a resonance in the suspension bushings (and perhaps the steering rack mount bushings.)

I also checked the fluid level - engine running - it was at the minimum line. Went to a NAPA in Los Angeles (I drove it here from NJ..) bought the Pentosin CF-11 fluid and brought it up to the max level (engine running.) Doesn't seem to have made much difference. I realized despite all my prep (like replacing the cooling pipes) to get the truck ready for a 7,000 mile jaunt - I hadn't checked this level before leaving home, and actually hadn't checked it in about 6,000 miles (and I didn't remember the dipstick, which makes me think may have never checked it..)

Poked around - felt the steering rack boots - feel empty (no fluid accumulation), looked at the belly pan under the power steering pump, dry as a bone.. so no sign of any leaks and no dribbling when parked.

My WAG at the moment is - this is sorta normal. I'm on Michelin's that have about 35% tread left and they spent about 700 miles crossing the western deserts at 80-90 MPH (gotta love Utah's 80 MPH speedlimit). No other oddities except the shudder, which my guess is - the rubber gripping and releasing as they try to rotate without the wheels turning. There is no sign of this with the truck moving (can pull U turns with the best of the LA drivers - also gotta love the narrow turning circle on such a big vehicle..)

Just in case I decide to have Porsche check it out - I'll be in LA for 2 weeks - any recommendations on an authorized Porsche dealer (truck is still under CPO..)?

[Loren]

Per page 271 of the 2006 Cayenne S Owners Manual

"Check the fluid level with the engine stopped and cold (engine temperature approx. 68° F or 20°C)."

[deilenberger]

Loren, thanks. Running or not running didn't make a bunch of difference in the level. Will see tomorrow AM if hot/cold makes more. When I looked at the level this AM - it was still cold..

[deilenberger]

Just checked.. running/not-running doesn't make any real difference. I did notice a burned smell to the fluid - which makes me think the cooling coil for it isn't quite adequate for long desert runs at 100F.. Loren - do you happen to know the flush quantity?

[Loren]

Per page 386 of the 2006 Cayenne S Owners Manual...

"Power steering approx. 1.6 quarts (1.5 liters) Pentosin CHF 11 S"

[wvicary]

My Cayenne also does this slight shudder, I've noticed it on other Cayennes also and just considered it normal.

[deilenberger]

My Cayenne also does this slight shudder, I've noticed it on other Cayennes also and just considered it normal.

Thanks for the confirmation.. Mine might have been doing it to some extent all along, but it's odd that I really just noticed it after the desert runs. What it looks like is the bushings on the steering rack allowing it to move slightly sideway, and then causing it to rebound back to normal position (I'd guess when the recovery force of the bushings exceeds the grip of the tire.)

I think I'll visit NAPA again tomorrow AM buy another liter of Pensotin, and see if I can borrow a friends driveway. Then find a turkey-baster, and do the poor-mans flush (drain reservior, refill, repeat after running engine and going lock to lock - all until the fluid looks clear.). Done that a number of times on my BMWs, which turn the fluid (most of them use Dexron-ATF) to a coffee like appearance after a few years.

Returning to the east coast in a few weeks I'll be going through no deserts.. :) I may be exceeding 100 MPH (be going through Montana), but in more temperate conditions.

Thanks again!

[wvicary]

CHF 11.S has been replaced by Pentosin 202. I'm not sure why they reformulated it but heard rumors it has better anti foam abilities and can handle higher heat.

[deilenberger]

CHF 11.S has been replaced by Pentosin 202. I'm not sure why they reformulated it but heard rumors it has better anti foam abilities and can handle higher heat.

Entirely possible - unfortunately - NAPA only has the 11.S.. I may see if there is a semi-convenient Porsche dealer on the way to my friends..

[deilenberger]

Fixed,

Did the poor man's flush described above with the Pensotin 202 fluid ($24/liter from a Porsche dealer).. managed 3 drain reservoir/fill reservoir/run-lock-to-lock/repeat.

The stuff coming out was quite dark (about like coffee without cream..) and smelled toasted. The stuff going in is green in color, has a slight acrid odor.

After doing the 3 drain/fill/drain/repeat.. no more shudder. If you have this - it's a cheap try at fixing it. Probably be better with Porsches prescribed 2 man process to flush the system, but this worked and cost was minimal. I might do the full flush when I get back to the east coast.. but right now - the shudder is gone and the steering actually feels better (quicker? Is that possible? Or perhaps less effort required making it feel quicker..)

[wvicary]

Interesting. I'll have to flush mine and see if it improves.

[deilenberger]

Noticed later today a bit of it is still evident, but nothing like before. I think the surface you're parked on makes a big difference, and perhaps the tire temperature (warmer = stickier)..