bcr84urq

windows no worky. Both 257N P/N. When I attach my ProDiag WSC on old unit is XX335, WSC on replacement is XX435 (can't recall first 2 numbers - 46?) Anyway - can WSC be recoded? Need a different replacement? TIA-

Brandon
'01 S4
'84 ur-quattro 20Vt
www.urq25.com
-It will be the largest gathering of ur-quattros ever in NA

homer-j-fong

they dont work at all, or the auto up/down function stopped working?

bcr84urq

They don't work at all. So I reconnected my old pump. So now I have windows - but no locking.

homer-j-fong

it is usually the graphite disk inside, they tend to implode. Its pretty easy to change out. Let me see if I can find my old writeup.

Mr. Bungle

No need for recoding and the part from the Corrado was '90 from eBay. Email me if you have any questions.

homer-j-fong

So after about a year and a half with VAG codes for my central locking pump, it finally died on me last week. After STFA and reading the tech article and a tread by Brazil@MirrorWorksDetail.com (https://forums.audiworld.com/s4/msgs/2637462.phtml) I decided to try and just replace the center graphite disk by using one from an Audi 90. I think a new S4 pump assembly is like 500 beans, so nuts to that

Here are some pics incase anyone else cares to do this. It really is easy. Probably took all of 45 minutes after it was removed from the trunk, including taking the photos.

1988 Audi 90 vacuum lock pump
Part # 443 862 257 E
ebay for $50

I would assume a large majority of audi pumps are basically the same internally so other model may work out fine as well.

Used Audi 90 pump
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/90pump.jpg">

S4 pump left, 90 pump right
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/S4and90pumps.jpg">

Here is the S4 pump with the housing and circuit board removed. Remove the top 3 screws to take off the top graphite disk.
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/s4pumpinside.jpg">

Here is the top disk removed and the destroyed central graphite disk and spindle
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/s4pumptopdiskremoved.jpg">

Here is the 90 pump with the housing removed
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/90pumpinside.jpg">

And the 90 pump with the top graphite disk removed
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/90pumptopdiskremoved.jpg">

Remove the entire motor assembly from the 90 pump and pry off the bottom most disk, this will get the center disk and the spindle cap free without having to grab it with pliers are risk cracking it.
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/90pumpcentraldiskremoval.jpg">

Removed
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/90pumpcentraldiskremoval2.jpg">

Here is a picture of both central disks side by side, S4 left, 90 right. Notice the the spindle cap is diffent. That is why we want to be careful when removing it from the 90 pump. The spindle itself is the same shape, so the cap from the 90 fits on just fine. Also the shape of the spindle cap, and how it locks into the central disk are different.
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/centerdiskcompare.jpg">

Close up S4 central disk:
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/centerdisks4.jpg">

Close up 90 central disk:
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/centerdisk90.jpg">

This is the underside of the outer ring of the center disk sandwich. This is the side that should face down.
Now when you go to put things back together you need to make sure that the two groves shown in this picture line up with the two vacuum holes circled in red in the following picture:
<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/s4outsideringdiskunderside.jpg">

<img src="http://i176.photobucket.com/albums/w197/homer-j-fong/bottomdiskvacuumholes2.jpg">



Put back together in reverse and you are good to go.

bcr84urq

OK yah - decided to jsut swap the two pump motors - keep the same elecs - no need to recode...thx