How to replace leaking rear seal on power steering pump - A Pictorial
 

This write up is for the ZF pumps found on the 616/617 engines. The featured pump is off an '82 240D.


I have a ZF pump that was leaking from the large O-ring on the rear of the pump. To replace the seal, you have to remove the pump and partially disassemble it.

Pic 1: Pump is removed from car and your are looking at the back of the pump. There is a large snap ring which may be difficult to see in the picture which you will eventually have to remove.

Pic 2: View of front of the pump. I went ahead and removed the pulley to get access to the front seal. You don't have to remove the pulley to just replace the O-ring at the rear of the pump. Simply use an impact gun to remove and later reattach the pulley nut.

Pic 3: You will need a large 3 jaw puller to remove the pulley if you so choose. It may be stuck so be careful you don't bend the pulley. Use heat to help facilitate removal if necessary.

Pic 4: You will need a 6-inch C - clamp to compress the rear cover of the pump to remove the rear access plate. After compressing the cover, remove the snap ring. Note the orientation of the snap ring for later reinstallation.

Pic 5: Snap ring removed.

Nice job.

Pic 6: My cover was a little stuck so I used vice grips to help pull it off.

Pic 7: Cover is removed and your O-ring sits right in there. Pull it out and put the new one in.

Pic 8: The pump is attached to the engine via three bolts. Two on the top and one on the bottom.

You'll need to bleed the pump when you're done. Jack up the front of the car so both front wheels are off the ground. Fill the pump up, put the lid on, start the car and turn the wheels side to side to full lock a few times to bleed the air out. Turn off the car, remove the lid and add fluid as needed.

Good luck!

Scott

did you have any trouble with the pump not pumping when you put it back in? It looks pretty easy, I need to do it.

No trouble at all.

I should add, to bleed the pump when done, put the front wheels in the air and simply crank the wheels side to side a few times with the engine running then add more fluid as needed. No need to disconnect the return line and run it into a container, etc... It is very, very easy to bleed the air out.

Scott

It's in the Wiki
 

This DIY is now in the DIY Articles Wiki HERE.

Thanks Scott!

any info on the front seal?

Its described under Pic 2. Remove the pulley and you'll see the seal. Just pull it out.

Scott

That seal did not need to be pressed out, correct?

Good point. I didn't change mine so I can't say with certainty. I'd like to hear from someone who has.

Scott

unfortunately, I tossed an entire pump b/c I could not figure out the front seal.

Nice write-up.. as usual.

front seal is easy- I did it w/ a seal puller(real handy tool), or one could modify a screwdriver to remove the seal. install w/ a large socket which is the same diameter as the seal, press on.

you will have to remove the pulley, of course. For peeps whom dont have the tools- stop in any decent mechanics shop with the pump, generally you can get someone to remove the pulley for a few bucks. then proceed. no special tools needed to install the pulley.





seal puller

thanks.. wish I knew this sooner.

can you remove the pulley with a typical three-claw puller? Like used on the crank pulley?

edit: there's a picture of the puller in the first post... duh