It REALLY ticks me off when companies are so greedy that they forget about the customer....
Case in point:
My wife's W140 developed a TINY leak in the Front Shaft Seal of the Power Steering pump. Since it drives me NUTS to have orange PS fluid on my nice white floors, I decided to finally deal with it....
So, lets look in the EPC to find a repair/seal kit... NONE!!
Ok, says I, thinking I'm sooo smart, I will track down the manufacturer (ZF Pumps) in Germany..... and write them.... "Oh, no, we don't sell seal kits... you have to purchase a WHOLE NEW PUMP!!!"
What sort of idiot company builds pumps but NO seals to service it??!!
Hmmmm, this means war.... After numerous routes, I FINALLY track down a BMW part number for a "similar" pump.. yada yada ya......
I finally found a company who makes a seal kit for $12 Bucks!!! Ha!! I win the war MB/ZF!!! No need to buy your silly $500 Pump, all for a stupid $1 front seal!!
Anyway, here is a Step-by-Step on how to do your own repair.
I wonder if there is a DIY or a REMEDY for the steering pump noise. For the last 2 years every damn winter when I turn the steering wheel to leave the garage I hear a whistle like sound coming from the pump and every summer it dissapears, whats the deal with seasonal temperature changes I still dont know though and even though its pretty chilly allready no noise coming from the pump this year, weird.
Nice pictorial steps! I may need to do this myself, I have a '97 S420 with a leak somewhere on the pump, not sure, buy I do see a fluid build-up under pump and behind reservoir. Where did you purchase your specialty tools? Would Northern Tools or Harbor Freight carry them?
G-AMG, I replaced my PS pump yesterday using your procedure, Things on my '97 were slightly different, so I thought I'd share.
The back side bolts on mine were 13mm hex instead of E12.
You are correct, that second bold it a major pain to get at! It actually took me longer to get this one bolt out and in than the entire rest of the job! I actually was not able to get at it from under the car since I didn't have extensions long enough to reach in all the way from the pittman arm. I was able to access it from the top by reaching in there with my left hand and working my way around kind of backwards. Obviously, I wasn't able to get a torque wrench on that bolt, so I'm going to ask the mechanic to torque it for me next time I have the car in for service.
If you don't have the counter stay, leave the belt on when you break torque on the three pulley bolts. The belt provides enough friction to hold the pulley in place. The same goes for re-torquing them. Put the bolts on and snug them up, install the belt, and then torque.
For everyone else, G-AMG's pictures don't really show it in too much detail, but the pump is on a mounting bracket as well. If you look at the pictures showing the 6mm Inhex bolt you can see it. That bolt is on the bracket and not the pump itself. The bracket is connected to the pump with two 13mm hex bolts on the front and two 6mm hex bolts at the back.
Thanks again for the great write-up, G-AMG! :thumbsup:
Great tutorial. Removing all of the dust shields below the engine on the left side (fender liner, etc.) make accessing the lower bolt on the back much easier. I did not rebuild my pump. Instead, I replaced it with a rebuilt one that I bought from Autopartswarehouse.com. They had the best price on the ZF pump and it arrived the next day after ordering it. No shipping and no sales tax. $363.95 including $50 for the core return. Of course, rebuilding it yourself will save you significantly. I am a good mechanic but did not want to take the chance of not doing it right.
I am ready to tackle this tommow and have a question. is it really necessary to remove the entire pump body ? it appears to me that once you take the 13MM bolts from the fromnt, one can easily replace the seals ?...is the issue w/ seals potentially falling out ? TIA
Never even thought of that. I guess, "theoretically" it is "possible".
You would need to take great care on Re-Install, because that one "Base Plate" is not held on by anything... and "if" it comes off, The Impeller Blades will fall out along with it.
This is why I lowered the "Body" of the Pump ONTO the inner workings, so that "Base Plate" wouldn't fall off.
I guess I am a "Concrete Thinking Mechanic"... and follow the WIS instructions without much questioning.... at least this tends to keep me out of trouble...
Mission accomplished - took the belt out, removed the pulley, took out 5 of 13MM bolts out, chaged out the seal and gaskets, then re-install. No leaks so far, total time took eas less than an hour.
The PAS pump on my CL420 has been making noises when cold, and now there's a leak from the front seal (fluid on the edge of the poly-V belt). Exchange pumps here in the UK are about £336 (Euro Car Parts), so I was glad to read this thread. Called my local M-B dealer with the part number and ordered a seal kit for just 12 quid. Hopefully this will do the job. Many thanks G-AMG for putting this on here, and also to llast993 for showing it can be done without taking the whole pump out.
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