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944 Power Steering Rack Seal Kit Replacement


When replacing the seals make sure to tap them in completely and evenly so they seat properly. I like to match up a socket that is the same size as the outer ring of the seal so I can press/tap the seals in evenly all at once.

When removing the seals they can be tapped out with anything from a socket to the rack itself. If you use the rack itself (not recommended but sometimes it's the only thing you have around that is the correct size) please do not hit the rack. Place a block of wood on top of the rack and hit the wood. This keeps the rack ends from getting chipped.

Wash everything while working on the rack and before you put the rack back together. Dirt and gunk is what caused your rack to leak in the first place. Dirt getting wedged in between the wiper seals and letting fluid pass is the main cause of leaky racks. The cleaner you keep the inside while working on it, the longer your rack will last. I also recommend replacing or cleaning your fluid reservoir when reinstalling. This catches quite a bit of that dirt and gunk we don't want and puts it right back inside of your freshly sealed rack.

Before installing the rack, go down to your local auto parts store and match up those little copper washers that go onto the lines connecting the rack. The little bit that it costs for new ones now is far less than the time it would take to reach around to the back of the rack and replace them if they leak later on. THEY WILL LEAK LATER ON.

If your boots are torn please get new ones. They are cheep and you can get them right off ebay for around $9. These help keep the dirt off of your rack. (they are not for holding fluid as you might think from the looks of your leaky rack)

If, when full of fluid, your rack felt week when turning one way, or both ways, you may have a broken pressure release valve spring inside the gear. You can check this while you have the rack apart. On the gear/spline piece that came out of the gear casting you will see a bolt holding a plate that covers two round pieces. This is located on the side of the gear piece between the band seals. Take this bolt out and the plate will come off with it. Remove the two round cap pieces and under them will be two springs. Check the springs to see if they are broken. If they are you should take them down to your local auto parts/hardware store and match them up as best as possible. This is your variable steering assist mechanism. As your rmp increases, so does the pressure of your power steering fluid. When the pressure gets to high this relieves the fluid back to the tank. If the spring is broken it is relieving to early and not giving your enough assistance during low rpm's. If this is your problem and you need more information on this please feel free to email me.

Also I would like to add that this is the way "I reseal a rack." The procedures discussed in this how to are more than likely not recommended by ZF or Porsche. This is the procedure that works for me but if you at any time feel uncomfortable with doing this yourself please consult your Porsche mechanic. It is good to explore and understand the intricate inner workings of your car's components and this can be done without any mishaps or damage if you practice patients, cleanliness and ask lots of questions.

Step 1: Step 1: Take the rack off of the car and place it on a large table / workspace. Make sure your workspace is large enough to lay out the disassembled rack so you don't lose track of where the pieces go. Also I would reccomend giving the rack a good cleaning before you start to get most of the road gunk and dirt off so none of it gets inside of your rack while you are completing your reseal.

Step2:Step2: Remove the rubber mounts from the body of the rack. The aluminum U bracket slides off and lets the rubber mounts open up so they can come off the rack.

Step 3:Step 3: Take off the metal hoses that are on the rack. You use an allen key to get them off but they may be on there tight. I used an end wrench as a "cheeter bar" as you can see in the picture above but be careful, they come loose all at once. The picture below shows what happens when you are not careful, like me.

Also contained on the ends of the metal hoses are 8 o-rings. Please match them up now with the ones from your kit.


Step 4: Step 4: Now this part is a little tricky. Where the body of the rack meets the gear casting there is a little ring with 2 notches in it. The correct way to take this off is with a special spanner wrench, but we are trying to get the job done and not collect a bunch of tools we will only use once. Because of this, just use somthing like you see in the picture above to tap the ring counter clockwise so it will unscrew. After it moves anywhere from a 1/4 to 1/2 turn it should be loose enough to unscrew the rest of the way by hand.

rackHere is the rack after the ring has been removed and the rack housing has been slid back.

rack housing removedThis is the rack housing removed from the rack.

Step 5:Step 5: Remove the 3 bolts on top of the gear casting and pull the flat piece off as shown in the picture. Contained in this flat piece is one of the wiper seals and an O-ring. Match these up together now so you can keep track of which seals and O-rings go where.

Step 6:Step 6: Disassemble this piece using a set of snap ring pliers. It should slide off the open end of the rack. The piece has 3 o-rings and one band seal that needs to be replaced. Please match the seals up with this piece now to avoid confusion later on.

disassembled piece The disassembled piece should look like this. On a side note, whether your rack has them on it now or not, your kit comes with the correct size o-rings for one to be placed under each band seal. It is very important when replacing the band seals that these o-rings are not left out.

Step 7: Step 7: After completing step 6, the piece shown above should slide off the open end of the rack. There is one wiper seal on the inside and a hard plastic or copper stop ring under it. These should be tapped or pressed out at this time and matched up with their respective pieces contained in your kit. Also there is an o-ring and plastic band on the outside of this piece. Please keep the plastic band and match up the respective o-ring from your kit.

Step 8:Step 8: Grab ahold of the spline on top of the gear casting and pull vertically. As it comes up and out of the gear casting it should spin slightly. There are a number of rings and bearings around this spline piece. Please keep track of where each one goes so reassembly is not a problem.

On this spline piece you will see 4 band seals. Please match these up now with the 4 band seals and 4 o-rings from your kit. At the bottom of the gear casting where this piece was sitting you will find another wiper seal. This one can be a little tricky to get out. Sometimes CAREFUL destruction of the seal is necessary to remove the old one. If this has to be done, please be certain not to score or scrape the seal seat with what ever you are prying at the seal with. If the seal seat is nicked or scored significantly the fluid may leak around the seal. Here is a picture of a seal that had to be destroyed in order to be taken out. The trick is to bend the outer edges in towards the center until the seal colapses onto itself.

When this seal is out, please match it up with the one in your kit.

When this seal is out, please match it up with the one in your kit.
Step 9:Step 9: You can now remove the rack itself from the gear casting for proper cleaning before reinstalling. It may be necessary to loosen the plate on the front side of the gear casting to get the rack back into place. This is done by loosening the two bolts on the face of the plate. Contained inside the plate is a spring which puts pressure on the rack itself giving your steering that "tight" feeling.

Step 10: Step 10: Inside of your rack housing is your last wiper seal. This piece has two plastic rings behind it. The one you can see in the picture above should be pulled out of the rack first to avoid damage. Then the seal and ring should be tapped out from this side down. Please try to tap it out evenly because if it starts going crooked it may make it harder to remove. When this piece is out please match it up with the correct wiper seal that is in your kit.


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