I have a 2007 911 Turbo with a bad power steering leak. I'll give a back story starting from last Spring..might be long but here goes:

When taking the car out of winter storage last March I noticed a ton of Pentosin under the car. Long story short, turns out my slave cylinder was shot and spewing fluid from the front of it where the actuator rod is. DIY fix and $900 later for a new slave and accumulator and I was back up and running.

The car never was 100% right though. On hard right turns when pulling out of my garage I would notice a slight whine from the power steering. Also very occasionally the clutch pedal would get hard when rolling slowly such as when I was backing in my garage. I attributed it to air in the system but after bleeding twice was never able to get more air out. I drove about 2000 miles this season without getting under the car again, except one time perhaps 4 months back when I installed some poly transmission mounts. I noticed no leak at the time and had all the plastic off underneath.

I began noticing a slight whine from the rear of the car when going slowly but assumed it was due to the transmission mount and motor mounts I installed since the first time I noticed it was right after. It was similar to when you back up quickly in a manual car (the noise the transmission makes). I honestly never gave the noise much thought.

Fast forward to today. I had the car on the lift doing my pre winter oil change. I immediately noticed an immense amount of Pentosin leaking from above the rear most plastic under the car. I pulled the plastic off and the leak looked identical to the one that developed from the slave over the last winter. I thought "well that sucks" and knowing this was my last drive for the season and I was going straight home and parking it for the next 4 months I figured I would limp it home and deal with it in the Spring. after all the car had driven just fine all season with the exception of what I mentioned above. I did reach up around the slave but didnt feel anything leaking. The fluid was leaking from the passenger side above the starter. Again, same as last year.

So, I buttoned the car up and began driving home making sure to try and stay off the clutch pedal for my 15 mile all highway drive home. All was fine until I hit stop and go traffic. Fml right? So for 15 mins i was having to push the clutch in and out with nowhere to go. At the very end of the traffic the pedal suddenly felt different and i thought "yep, and here we go. I'm about to break down in a one lane highway". The clutch pedal got very hard. Probably took 70 lbs of pressure just to keep it pressed down. Luckily the traffic ended a min later so I began driving the rest of the way. when i got off my exit a few mins later I noticed a very loud whine from the rear as I slowed down. Clutch pedal was still very difficult to press but I switched to 3rd and drove through my village. The car was making some very not so great noises (whining that sped up or slowed with the speed of the car). I pulled in my driveway and the car was whining as I turned the wheel. At this point the car was making loud whining noises anytime it moved or I turned the wheel one way or the other.

I parked it and got out and immediately checked both reservoirs. The front clutch reservoir was full and the power steering was bone dry. When I took the cap off it was very difficult to remove and when it popped off air rushed out.

Thinking back on last Spring, I had the slave disconnected and out of the vehicle for a few days during the repairs, which means the fluid was allowed to drain from both reservoirs freely, and air was introduced into the system. At the time, I thought that both ends (PS reservoir and clutch reservoir) were connected, meaning they shared the same fluid, but am just learning that they are actually separated inside the slave by a bushing, and both systems do not actually share the same fluid (though it's the same type). I never added any Pentosin to the PS reservoir when I completed the repair. I did check the level after, and it appeared full, so I never thought much of it, but there was very possibly air in the system which brought the level down once it bled itself out. So I was quite possibly running the car for nearly 3000 miles with low PS fluid. Honestly at this point I'm not so sure the slave was ever the issue. Its possible I threw $900 into the car and the leak was never properly diagnosed.

So, obviously the power steering side of the system has a leak somewhere and its affecting the clutch. My questions are:

1. What are the chances I caused damage to the PS components (pump, rack, reservoir, lines, etc.) by running the car the last 5 or so miles home bone dry? If I add fluid will I likely be okay (assuming I find and fix the leak)?

2. With what I describe, where is the best place to start in diagnosing this issue? Again, the fluid is dripping from the passenger side of the transmission around the axle (from where the starter is). Is it 100% going to be in the area of the slave given this, or if the pump is leaking, is it possible the fluid is finding its way down toward the starter/transmission? I just want to know what I should expect for repairs and what the best way to tackle this is.

 

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Based on my experience (with the PS Reservoir - not the slave) the connections that press into those red fittings are the most likely suspects. When I was replacing my stock slave (which I highly recommend you consider) I removed all the plumbing from the reservoir to the slave. After putting everything back together and the engine back in the car, I had a dripping leak from the reservoir. Originally I thought it was from one of the three plugs I had fashioned for the removed plumbing to the slave, but it wound up being the return line from the PS rack. Kevin at UMW recommends replacing the reservoir with one from a GT2 which does not have the connections to the slave, but in my case, even doing that would still have a leak since my hose end was damaged. The red fitting below was the source of my problem. If I remember correctly there are two of these on the slave.



The problem was this cut that went around the circumference of the hose (that looked so perfect I thought it was part of the design until Kevin pointed out the problem):



Since the solution was to replace the hose, which required dropping the engine that I had just put back in, I took a different approach and replaced the end and the fitting with AN style fittings. Below the red fitting has been removed (there are three parts to the fitting, the red rim and 2 O rings) and the brass remaining tapped for the AN fitting:



The male AN fitting placed on the reservoir with high temp sealant:



The hose end, dremelled off and replaced with the femail AN fitting:



The connection in the car and the leak stopped:



The fittings I used:



Now why all of this was on the PS reservoir, I am sure you can accomplish the same things on the slave fittings once you determine where the problem is. The removal of those red fittings and the tapping of the fitting will probably require the removal of the slave.

As far as damage to the pump, it depends on how long it was running dry. Before I had replaced my slave, I had run low on PS fluid with the same noise being heard around hard turns. Topping the reservoir stopped the noise and bought me the time needed to change the slave to a GT2 slave setup. You can probably test the pump without doing any work by filling the reservoir back up, running the engine, checking the level and topping up any more required and seeing if the noise is still there. If it is the gearing inside the pump is probably damaged.

Again, if it were me, that over-engineered, prone to failure and inconsistent engagement feel stock slave would be coming out of your car.

Ed

 

Thank you for the reply. Very helpful. I was suspecting that the connections to the slave were the issue, particularly the return line (same style fitting as you had issues with, only on the slave end) but all connections to the slave are on the driver side of the car, and the fluid is dripping down from the passenger side. I've reached up above the transmission and felt around the slave where it bolts to the transmission, and couldn't feel any substantial fluid. I would have assumed that if the slave fittings were leaking, it would be dripping down from the driver side. I am honestly hoping that the slave and accumulator I just paid $850 for 5 months ago didn't develop the same leak (seems unlikely, but not impossible). Either way, I think it's best I delete this convoluted system and go with a GT2 (or similar style) slave, hope it fixes the leak wherever it is, and pray that the power steering system wasn't damaged when I refill it in the Spring.

So does anyone have any recommendations on a unit that will replace the stock slave, delete the accumulator, and plug the PS reservoir to negate the use of the lines that run from the PS reservoir to the slave? I know the BBi slave still uses those lines, and the fluid simply plumbs through the slave and returns back to the PS reservoir in that setup, but I feel like this design creates unnecessary chances for a leak to develop in the factory lines and I'd prefer to make the system as simple as possible. Why not just plug the fittings on the reservoir like you did, leave the lines in place (since I won't be dropping my engine anytime soon to remove them) and buy a GT2 slave, or is there more to the mod than that? Hell, couldn't you even do this with the BBi slave by plugging the two holes on the slave and at the PS reservoir end, and essentially leave the lines sitting in the car, not hooked to anything?

 

I would have to agree, All the connections, including the accumulator are on the driver side. The only thing on the passenger side is the slave push rod itself. It may be the slave that is bad:




From what I have read you have a few options:

1. BBI (BBI Slave) - The unit itself allows the connection from the PS Pump like you said and bolts right up to the same location where the current slave is. Issues are using new lines from the MC and new master cylinder and flushing the hell out of it. They currently have a $200 discount which makes this closer to the EVOMS option
2. EVOMS GT2 repalcement kit (GT2 Clutch Slave) - similar to what I did. Includes the MC, spring, line, cap and slave with bracket so you don't have to drill/tap moving the slave to the driver side. You will still need to deal with the PS Pump & Reservoir
3. DIY - GT2 slave, master cylinder, line, spring and slave Reservoir cap. Need to deal with the PS Pump & Reservoir, and unless you can find and modify the bracket that I think a Rennlister made for the 996, you will need to drill/tap the trans case and pull the case and change the fork as I did. You will also have to scavenge the end off the original line to connect it back to the pipe going to the master cylinder.

The BBI and EVOMS options are about the same price, give or take. The BBI does not require messing with the PS Pump/Reservoir, the other 2 options do. The least expensive in terms of parts is the DIY, which I think ran me about $600 for the parts, including a clutch fork to move it to the driver side and the plugs/fittings for the PS Reservoir. If I had the money in the budget, I would have opted for the GT2 reservoir to save some time (but in my case I would have still had the leak to deal with since the problem was with the line end).

Both the last 2 options require you doing something about the PS pump. The pump is really 2 pumps,one for the PS rack and one for the slave. You either need to go to a GT2 PS Pump/Reservoir or pull the PS pump apart, remove the coupler and put it back together hoping it does not leak since I do not believe the flat O ring between the halves is sold by anyone that I found. If you pair the GT2 pump with the 997TT reservoir to avoid the cost of GT2 reservoir, you still have to plug the reservoir for the lines that no longer will be used.

The "easiest" solution in situ, in my opinion having done the work before with the engine out, would be the EVOMS kit with a GT2 PS Pump/Reservoir. You may still have an issue with the PS rack return line, but you can do what I did if needed. This was you do not have to drill/tap, split the pump and remove the coupler nor deal with plugging the pump/reservoir. The only thing that is not clear on their website is if there are any mods needed to the bracket to work with a 997 since the trans case is different than the 996, where they originally developed the kit.

Just remember you will have a heavier clutch than before, and if you drive in rush hour traffic all the time, that may be an issue. For me, I don't care either way, I have no trouble with a heavier clutch in any condition, especially since I don't stall or over rev the damn thing any more.

No matter what, you need to make sure you have no leaks by the engine due to the flammability of the Pentosin fluid.

Ed

 

I found list while browsing through the marketplace on Rennlist. It's a reservoir for a little less than retail but pretty new.

GT PS Reservoir

Ed