PS Fluid Leak

[MH996TT]

Can anyone confirm that a large steering fluid leak in front of the engine is most likely one of the rubber steering fluid lines. If so, how could I tell which lines are which in the PET6 diagram. I would imagine they are pretty easy to replace...

Thanks

[Loren]

It is probably best to put the car on a lift and pull the bottom cover so you can see where it is leaking. I've actually seen one of the metal lines leak that was damaged by a road hazard -- or an off-road experience ;)

[MH996TT]

Thanks for the fast reply Loren. I'm guessing that the rubber was rubbed through since I watched a technician tie it back because he noticed it was rubbing.

[a1certified]

Thanks for the fast reply Loren. I'm guessing that the rubber was rubbed through since I watched a technician tie it back because he noticed it was rubbing.

With respect to the power steering fluid, is there a recommended change interval that is recommended? I always hear about the recommended change intervals for the engine oil, transmission fluid, coolant, brake fluid, etc. but don't really hear much about the power steering fluid. To change, is there a drain plug somewhere?

David

[Loren]

Unless it has the system has been broken and contaminated or fluid has leaked there is no need to add or change power steering fluid.

[a1certified]

Unless it has the system has been broken and contaminated or fluid has leaked there is no need to add or change power steering fluid.

Is this because the composition of the fluid is different than other automotive fluids, that it is under such low stress, is it sealed from the environment better? I'm curious why this fluid has such a long life expectancy when other fluids (I think coolant is one) oxidize over time and become less beneficial even if not used for a certain mileage.

[Loren]

There might be some slow loss of fluid over time (oxidation, evaporation, etc.) but under normal use there is no need to flush/replace it.

[MH996TT]

In my effort to find the PS fluid leak I have narrowed it down to somewhere directly above or below the clutch system pressure accumulator (plastic spherical pressure vessle) mounted above the right rear axel.

My new questions are as follows:

1. Is the PS fluid circuit seperate from all other hydraulic systems (ie. clutch)

2. Is it as hard as it looks to remove and replace the PS lines back by the axel?

3. Any chance there would be any DIY info on this matter?

TIA

Matt

[Loren]

1. Yes, they are separate circuits.

2. Hard to say - are you sure which line it is?

3. Sorry, no - this is not even covered in the service manual (that I can find).

[MH996TT]

1. Yes, they are separate circuits.

2. Hard to say - are you sure which line it is?

3. Sorry, no - this is not even covered in the service manual (that I can find).

Loren,

The fixture that the accumulator screws into has a small diameter rubber line clipped directly above where the accumulator screws in. The leak is either from that hose very near the accumulator fitting or accumulator fitting itself. If it is the accumulator fitting, that would mean that the PS circuit and the clutch both use the accumulator?

Thanks again for the help...

[Loren]

The accumulator is part of the hydraulic clutch. Power steering and the hydraulic clutch use the same fluid (on TT) but I'm pretty sure they are not connected.

Which fluid is low the clutch reservoir in the front trunk or the power steering reservoir in the engine compartment?

[MH996TT]

The steering was groaning so I added 2 cups pentosin to PS back in the engine bay (dipstick was bone dry). The more I look at diagrams and crawl under the car, the more I realize I have no idea where the PS routing is located. Thanks for the help...

Matt

[Loren]

Where are you located?

[MH996TT]

Denver

[Loren]

A couple of our moderators live in that area. You might PM clord and/or grant and see if they are willing to take a look at it for you.

[MH996TT]

OK, I am 97% sure that the leak is coming from the fitting for the accumulator. I spent a half hour laying under the car cleaning and wiping and watching this thing drip. The fluid will gather around the area where the accumulator fitting meets the master cylinder.

Does anyone (Loren :help: ) know what would be the tool of choice for the R&R? I tried a 19mm with no luck. A 21mm seems like it would be too big...

Not sure if this is possible but it would be a lot cheaper to change just the o-ring if that is what failed...

Matt

[PTEC]

I've found the best tool for removing the accumulator is a band type oil filter wrench. I'll usually remove the bracket for the two coolant lines from the transmission just to give myself a bit more room. Make sure you depressurize the system before cracking it open. Also make sure you clean the pentosin off anything rubber it comes in contact with, it'll will eventually eat through rubber.

[MH996TT]

PTEC,

Thanks for the tip. What is the best way to depressurize the accumulator? I was hoping that since it is leaking the pressure would be low - maybe not low enough?

Do you normally just replace the sealing ring?

Thanks again...

[PTEC]

You can depressurize the system by pressing the pedal about 25 times. Youll feel the assist start to go away and the pedal will get more difficult to press.

As for replacing just the sealing ring.... I dont know if thats possible. You may want to call your local dealer about that and see if just the o ring is available. I've never actually seen a leak from this area. Usually when Im removing an accumulator is because it has failed and Im replacing it.

[MH996TT]

If I could get one more push in the right direction, I think I will have this problem fixed and my car back on the road while there are still a few leaves on the trees. Loren and PTEC, thanks a ton for taking the time to help me out...

I have a new clutch slave cylinder and a new pressure accumulator. I am replacing both because I want to make sure I fix it and I don’t want to get back under there anytime soon…

I have read the repair manual for these procedures but as many of you probably know, the German English is a little vague. Can someone please describe the Pentosin fill and bleed procedure? Some basic questions that I have are:

1. Does the slave cylinder or pressure accumulator need to be primed with Pentosin?

2. Is it difficult to get the slave cyl. Pushrod aligned?

3. Can I use a hand pump bleeder to bleed the system?

4. How do I avoid over filling?

5. Is there more than one bleed location? I know about the one on the slave.

6. Any other obscure tips to keep me from causing unneeded damage?

Sorry for all the questions. I promise to attempt a DIY post for this if I am successful

TIA

[Loren]

Per the 996TT workshop manual...

1. Fill supply tank.

2. Open bleeder valve on the servo unit.

Note: - Make sure that the reservoir is not sucked dry. Top up during the procedure if necessary!

3. Pump with the clutch pedal until Pentosin emerges without air bubbles at the bleeder valve of the servo unit (use collecting bottle).

Notes:

- If a bleeding device filled with Pentosin is available, clutch bleeding can proceed in the same manner as for previous systems!

- To do this, the bleeding device is connected to the clutch reservoir at the front!

- The clutch high−pressure hydraulic system does not need to be bled in a special manner!

- It is sufficient to actuate the clutch pedal approx. 10 times with the engine running!

· The steering hydraulic system is bled in the usual manner!

[MH996TT]

The manual suggests to bleed steering system the "usual way". I take that to mean fill the reservoir, turn the steering wheel and recheck, and repeat until the level in the res stops dropping.

correct or not???

[Loren]

You asked for clutch bleeding so that is what I put in the previous post.

Here is the power steering procedure...

1. To fill the whole system after the installation of new steering components or lines or after a substantial loss of hydraulic fluid, briefly start the engine a few times and, when it fires, switch it off again immediately. This procedure causes the fluid level in the reservoir to fall rapidly, so constantly add Pentosin CHF 11 S. The reservoir must not be sucked dry.

2. If the fluid level in the reservoir does not fall any further when the engine is briefly turned over, start the engine and let it run at idling speed.

3. Rapidly turn the steering wheel from stop to stop several times so that the air can escape from the cylinders. At the end positions of the piston, do not pull the steering wheel with more force than is necessary in order to turn the steering (to prevent unnecessary build−up of pressure initially).

4. Observe fluid level during this procedure. If it continues to fall, add fluid until the level in the reservoir remains constant and no more air bubbles rise in the reservoir when the steering wheel is turned.

5. Switch off engine.

6. Wipe off the dipstick. Close and then reopen the cap. The fluid level should be in the designated "Cold range" (min./max. level at 20 °C). Top up with Pentosin if necessary. Do not add too much Pentosin! In warmed−up condition, the fluid level must not exceed the "Hot max" mark!

[MagnusB]

Where to buy Pentosin CHF 11 S?

Can I use any brand or?

[MagnusB]

Forget that :-)