I have an 87 S4 and the power steering pump shaft has about 2 to 3 mm of front to rear play, the 3 pulley bolts are tight ( and the pulley mount is tight as well) but the pump shaft moves front to back, I have never seen this much play on a PS pump. Other than that it seems to be working fine and there are no leaks. Does anyone have any ideas about what could be the cause, or am I looking at replacing the pump with a rebuilt unit . Thanks for your replies

 

going to have to replace it. The internals are shot if your 3 pulley bolts are tight.

 

Mrmerlin,

I believe there is a procedure for overhauling the power steering pump is on Jim's Technical CD's.

I was intially published in a UK 911 & Porsche magazine.

From looking at the procedure and the coloured pictures it looks as though the circlip has come off the shaft that hold the rotor onto the inside splined section of the drive shaft which would allow the shaft to move axially.

Porsche make a rebuild kit to overhaul this pump and the part number is 928 347 921 01 and it cost around $23 in the UK.

Tails 1990 928S4 Auto

 

Thanks for the replies now i gotta see what the owner wants to do.....

 

If Roger doesn't have the seal kit, which I highly doubt, you can get it from rennbay.com. There used to be an in depth video to guide you but you really don't need it. It is very straight forward. It will take you more time to remove the pump than to replace the seals.

 

Rebuilding the kit will not solve this as it will not address the excessive play in the shaft. Looks like you might need a new/rebuilt pump.

 

the pump isnt leaking it just has a lot of shaft movement so im thinking new pump time

 

Mrmerlin,

Could still only be the circlip on the main shaft that holds the rotor onto the drive shaft.

Would you not first check this with the owner before ordering a new pump, as it is very easy to strip out the pump. The hardest part, from the procedure I mentioned before. is the removal of the PS unit.

Tails 1990 928S4 Auto

 

well a pump disaasembly could mean a slipped C clip = remove and rebulid the pump =1 week in the shop waiting for parts VS remove old pump and replace with rebuilt unit 1 hour.. Hummmm The pump is original
Does anyone have an exploded pump diagram

 

Here is a link to the Rennbay video. It is posted on eBay with their kit. This video also works with the genuine porsche kit. It is not an exploded view diagram, but it does show the disassembly.

http://cgi.ebay.com/ebaymotors/Porsc...spagenameZWDVW

 

I need a faster connection its gonna take 38 mins to load that , Thanks

 

An exploded view of the pump via pictures available on JM's Technical CDs Version 2.15.
Tails 1990 928S4 Autp

 

I have the WSM set but not Jims CD

 

Mrmerlin
There is a wealth of knowledge on the 3 sets of Technical CDs in excess of WSM, such as all Technical Bulletins, Service Information Technik for all models, Specification Booklets for all models, Porsche Technical Training Booklets, HVAC stytems, electrical training, PSD bleeding procedure without Bosch Hammer and of course the Power Steering Article.

Well worth the investment.

Tails 1990 928S4 Auto

 

Where in the heck does one find these CDs?!? I've searched every which way and asked here before...no joy....