Here is my attempt at a DIY for the 997.2 power steering pump replacement. I was not able to find a service manual approach, so this attempt was cobbled together from multiple other postings.
This write-up is specific to the 997.2. Everything online was for boxters or earlier generations 911s and it appeared to me that even the 997.1 may be somewhat different.
Diagnosis of bad pump
The power steering was making a groaning noise, especially noticeable at idle when turning the wheel while not moving. Noise was RPM dependent too. The power steering reservoir was below the dipstick, topping it off improved but did not fix the sounds. Simple inspection did not show a leak at the pump, but did not attempt to look under panels at the steering rack. The noise was loudest while sitting in the car, with engine compartment open and moving the steering through the window it was hard to hear groaning to pinpoint it being pump vs. steering rack.
Many of the other postings say that when you spin the pump’s pulley it should be silent. Examining my pump showed a clicking/rattle if you are rotating one way and then change direction. Inspecting the new Porsche branded pump showed a similar sound. So I am not confident about what sounds are considered normal.
New pump sound
After pulling the airbox to see the pump clearly, there was dirt collecting around the pump’s shaft. I suspect it was weeping, causing level to drop before I caught on to the problem.
The 997.1 service manual states that if there is foaming in the reservoir (while running) it is an indicator of leaks allowing air into the system.
Difficulty of install
I have about 6 hours into the project, 7 is more like it. Much of that was simply staring at the configuration to figure out what besides the pump needs to be detached. Most of the piping/electrical connectors use tabs or buttons that are depressed to allow the connector to be disconnected. However, its feels like most of the tabs are facing away from you so I spent lots of time with a mirror cursing. If you follow this DIY, I think 4 hours is realistic, with 3 if you have worked on the top of the engine before. It is a harder job than spark plugs, easier than doing the lower control arms on a C4S.
The main difficulties are fiddly crap. Some of the job requires your hand in positions where you can’t see what is happening, working by feel. Access is very limited; sausage fingers will be hating life. There is only one real challenge, and that is removing the low pressure return line at the back of the pump.
Reinstalling the serpentine belt required 2 people, otherwise this is a one person job.
Much of the fluid can be siphoned out of the reservoir, but the Pentosin fluid is very low viscosity. Once it drips it will flow all over. The 997.1 service manual states that Pentosin (at least flavor CHF11S) will degrade rubber and some plastics, it should not come in contact with skin, use gloves, etc.
Should you do this project?
The really hard part is almost the last step. You can back out of the project fairly easily and drive the car to the pros. But once you commit the car will need to be trailerd if you screw the pooch.
Pump part # 9A131402006 This includes the reservoir and mounting bracket. Around $480 out the door, not likely to be in stock but available from the Porsche distribution centers in around 3-5 days. Non Porsche vendors were quoting higher prices.
Pentosin power steering fluid (CHF 202 seems to be the newest flavor and is a Porsche recommended fluid, CHF 11S is also allowed but older. Both can be mixed.) Comes in 1 liter. If only replacing the pump 1 liter is more than enough, if you plan on draining lines you might need a little more. The entire system uses something like 1.4 liters.
The 997.1 service manual states that Pentosin will degrade rubber, recommended cleaning off rubber ASAP and rinsing with water. It specifically mentions checking coolant hoses for bulging if exposed. Use gloves. It can harm plastic – wires or body panels.
(this is not comprehensive, just the main stuff):
Nice to have:
- 30 mm wrench (not socket)
- 16 mm wrench (not socket), a 5/8 inch will work fine or a good quality crescent
- E Torx: 10 and 12. For some of the bolts the socket cannot be a long/deep style due to access issues.
- Torx: T25 and possibly a few of the smaller sizes. If you have the T handle style you might have clearance issues. I used the kind that fit into a handle.
- Basic metric socket set.
- Either a turkey baster or large needle to help drain the reservoir. The needle works much better as it can get lower in the reservoir and tends not to spill fluid as you move it around.
- Porsche special tool (can be made, explained later)
Porsche special tool.
- Wobbler or universal extension
- Stool or lift (your back will thank you)
- Small mirror
- Jeweler type thin screwdriver or similar
- A list of profanities as repeating the same one constantly gets boring.
- Drip pan or something under engine.
The attached image shows the tool.
This was found in a thread that was not for a 997. Looking at the return line for the pump, a circular tab needs to be pressed into the pump housing while pulling out the line in order to disconnect the return line. This video gives an idea but is not the 997 pump
To replicate this tool, I used a plastic (nylon probably) putty knife. Drill a 13/16 inch hole and then cut out an area so that the tool can be slid over the tubing. I used plastic instead of metal because it is rigid enough and trivial to work with. The tool takes only a few minutes to make. The diameter of the line the tool needs to fit over is 0.41 inch.
Some postings mentioned using a panel tool as an alternative. The one I tried was cumbersome and the opening looked too small to fit over the tube.
Since there were no factory instructions, the bolt torque settings are unknown. The bolts you will likely see are 7mm, 8mm (most of em) and 10mm (shaft diameter). Grades 8.8 and 10.9, the grades are stamped on the bolt’s head. These are values I found for use in aluminum, there are lots of variations but these are ballpark. When measuring the bolts, the ones closest to 8mm showed slightly undersized but way over 7mm.
- 7mm = 8 ft/lbs
- 8mm = 13 ft/lbs
- 10mm = 24 ft/lbs
- 7mm = 11 ft/lbs
- 8mm = 18 ft/lbs
- 10mm = 35 ft/lbs
By memory all the bolts are grade 8.8 except for the bolts for mounting the power steering pump to the block. In the 997.1 service manual it indicates the aircon bolts are M8 and would torque to 17 ftlb, but I cannot tell if they are the same as the 997.2 as the diagram looked different.
Review this video about changing the serpentine belt, much of what is done will be required. The spacer bolt can be left alone unless you plan to replace the belt too. There is no need to remove the top of the airbox; it can be taken out whole. Disconnect the rubber connector to the plenum at the airbox end of the tube (the oval end) and the mass flow sensor cable. The video mentions loosening the belt tensioner mounting bolt, this is not necessary.
As the video mentions, there is a vacuum tube that connects to the car on the bottom right side of the airbox. I disconnected where the rubber tube meets the airbox, instead of at the fitting that the youtube guy calls a “change valve”. I did it here because I figured if I broke something the hardline tube was cheaper/easier to fix. This is where I used the jeweler screwdriver to slide along the inside of the rubber tube to help ease it off.
Decide if you need to evaluate the power steering pump (i.e. do you already know the pump needs to be replaced). If the pump is toast, loosen the pump pulley bolts (3 of them). The tension of the serpentine belt prevents the pulley from rotating. You might use something similar to a wedge type doorstop between the pulley and the Aircon pulley if needed.
If you need to evaluate the pump, use the 30 mm wrench (turn CW) to compress the idler pulley so the serpentine belt can be shifted off. Play with the pump. Put the belt back on and then loosen the pulley bolts.
Use the 30 mm wrench to compress the idler pulley and move the belt off. In my case the idler pulley was very stiff, it would not return to the uncompressed position. Moving the idler through its range of motion loosened it up so that it worked normally.
Take off the pump’s pulley.
Remove the rubber line that connected the airbox to the throttle body.
Drain as much of the pump’s reservoir as possible.
Disconnect the throttle body electrical connector, you press on the center of the connector on the side facing away from you. I found it easier to push the connector together as I was pushing on the “button” and could feel it depress and then pull the connector apart.
Take off the four bolts mounting the throttle body to the intake plenum.
At this stage you should be seeing this:
The Aircon mounting bolts also hold a small bracket with a semicircular attachment that is also connected to the throttle body. I was able to disconnect the semicircle part by holding the rubber section and loosening the mounting nut. The screw in the thing seems to be mounted to the rubber, not the metal part behind the rubber. I removed the two aircon bolts but left the bracket attached to the electrical connector (I could not figure out how to disconnect it). There was enough slack to move it out of the way.
Disconnect or at least loosen the pressure line at the front of the pump, 16 mm wrench or substitute.
Time to commit: last chance to easily back out.
I evaluated 3 choices.
The pump is only held in by 3 etorx bolts, all very easy to get to. However the fluid return line connects to the back of the pump. Use the mirror to get an idea. This is where the Porsche special tool is needed. I am able to get my hand to the back of the pump and put the tool on the line. But you need to simultaneously press the tool (on the round tab) into the back of the pump while pulling on the return line in the opposite direction. With only the throttle body removed, I could only get one hand in there and was operating by feel. The return line looks like plastic but after the pump was removed it appeared to be metal. One of the pics shows the line.
Give it a shot, may the odds be ever in your favor. Notice that the pump’s bolts are still installed. Try it with them removed too. Since the tab needs to be pushed against the pump some resistance to the pump moving seemed to help.
Some of the other write-ups mention loosening the aircon unit to gain extra space. You will already have the two aircon bolts removed but the I could not get the unit to move, there may have been another bolt near the back. Even if the aircon could move, it did not look like the extra space would be helpful because the extra space is needed to the left or top of the pump.
Assuming you did not get lucky with simply reaching behind the pump, here are my approaches.
Loosening the alternator and shifting it away. There appear to be two mounting bolts. The leftmost seems like it will require a coolant hose to be removed to provide clearance. It might be possible to remove the right bolt, loosen the left and then rotate the alternator. But this did not appear to provide much clearance for the power steering pump and the area behind the alternator was crowded with potential interference. I did not attempt.
Shifting the intake plenum looks like it would make a lot of space. Hardware wise, removing the various connectors was easy. The plenum is held in place by two oval clamps, each using a torx screw. I removed screws but the clamps would not separate even with a fair amount of force. The metal was bending enough to give me pause. An included file in this write-up is the installation instructions for an aftermarket plenum which has directions on removing the stock plenum. It sounds like dealing with the rubber gaskets is a hassle and you cannot remove the plenum without cutting a tube. The plenum can be moved around though, which should provide enough space to get at the back of the power steering pump.
Option 3, no going back
The last approach, which is what I did, is to cut the top off the pump reservoir. The shape of the reservoir is such that upper section is the problem area and it is made of plastic. I used a hacksaw blade being careful not to come near the return line. About half way through the cut, I was able to use a wedge to snap the reservoir the rest of the way off. With the top of the reservoir gone, there is enough space to get a second hand behind the pump and the return line is trivial to remove.
By this point the return line is disconnected.
If not done already, remove the 3 pump mounting bolts and detach the high pressure line. The pump should come out with some wiggling.
I was concerned that since the pump was failing whatever bearings the shaft rides on may have contaminated the fluid. The lines can be removed at the steering rack to drain, however I used low pressure compressed air into the high pressure line to empty as much as possible. This approach removed a decent amount of fluid.
Install is more or less the reverse of removal. As mentioned above, there are estimated torque settings for some of the bolts. The bolts mounting the pump are a higher grade, look at the bolt heads for grading. Before installing the serpentine belt, hand spin the pulley (CCW) to load as much fluid as possible into the system.
Not sure about torque settings for the throttle body because its bolts mount into the composite/plastic plenum. Hand tight seems reasonable.
To tighten the pump pulley bolts, install them hand tight before installing the belt. Put on the belt, its tension will allow the pump bolts to fully tighten without spinning the pulley. The pulley is a composite material so I was concerned about over tightening but saw no issues. Installing the belt was a 2 person job, one person to compress the tensioner. Tempting to put the belt around the alternator last but the tensioner pully does not have a lip so that proved the easier target.
When you are close to installing the airbox, it is easiest to have the rubber connector to the throttle body completely detached. First connect the rubber connector to the throttle body leaving the hose clamp loose, then position the airbox in car. Push the oval section of the rubber connector onto the airbox. If the rubber connector will not seat on the airbox, it is likely because there are two tabs on the inside of the rubber connector and the one on the bottom is out of position.
Jobs to do while you are at it.
- Clean the throttle body. Carb cleaner or even a 409 type spray.
- Clean the mass air flow censor. They make a special cleaner just for this, I use the CRC electronics cleaner instead as it was easier to find and the ingredients are almost identical. (I have not researched whether Porsche recommends cleaning).
- Serpentine belt replacement. You will have already done 75% of the work needed. If you want to inspect the existing belt the service manual says it should be taken off completely, if doing so mark the direction as it should go back the same way.
- Replace air filters or if relatively new do a clean with compressed air.
Run the engine a brief period (seconds) and then check fluid level. I chose to leave the airbox off at this stage so that the pump could be inspected for leaks. Top off and repeat until stable. Start engine and move the wheel fully left/right, inspect again and check level. If you left the airbox off, you will generate a check engine light warning because the MAF sensor is disconnected. Unless you have an OBD tool that can reset a warning light, I believe the light will remain on. Most auto parts stores will let you borrow a generic OBD reader but am not sure if they would work with a Porsche.
I choose to disconnect the battery using the red key in the battery compartment – this resets the engine error codes. I left the battery disconnected for about an hour. Upon reconnect the horn will beep until the car remote is pressed. While this does turn off the warning light, at startup there were messages about PSM issues and some other warnings, but all went away after a few minutes of driving. Disconnecting the battery will prevent the car from passing a smog inspection until it has gone through a drive cycle (or basically driving it normally for a week). Some postings warned about losing radio settings or other personalization choices on a battery disconnect but I did not experience anything.
Test drive; check Pentosin level one last time. Swear never to do this again.