1999 E300D steering fluid leak
 

Hi guys, I have a 1999, W210 chassis E300D that has been leaking power steering fluid. I gunked the engine compartment and undercarriage and dried them thoroughly. I found that I have a pretty good leak at the point on the steering rack where two huge banjo bolts with reverse torx bolt heads secure two steel lines.

From gathering as much information as I can on this, it appears to be a common problem with the W210 chassis. There are two o-rings that must be replaced but I cannot find a part number for the replacement o-rings. Also, I have read opinions that state it is almost impossible to remove those banjo bolts so in some cases it is better to replace the steering rack itself.

I f anyone has information about this procedure, the replacement o-ring part numbers or whether it's better to replace the rack, please point me in the right direction. The leak is getting severe and we need this car as a daily driver.

Any advice will be truly appreciated. Thank you all!

Same thing happened on my 98. From my research I concluded that the only way really to do it right was to replace the rack. Also concluded that one of the best rebuilders out there is CVJ Axles out of Denver. If I ever replace the rack, I will buy it from them.

But, not wanting to spend the money, I thought I would give Lucas Power Steering Stop Leak a try. Over the course of three years I've been through about 1.5 bottles...I understand that 2 is the max. So the leak has slowed considerably...to the point where now I simply keep an eye on it and add a little every few months. During the winter months I top off with PS fluid because the Lucas product does cause the steering to stiffen when it's really cold outside (but that's only for the first few minutes).

Enter at your own risk.
 

About 30 years ago an old seasoned mechanic advise to to put a 'dab,' of brake fluid in my PS system. Of course this was a dodge van and I was in college and just trying to get by at the time.

He said the brake fluid would soften the seals and slow or stop the leak. I don't remember how much I put in the PS system but I reckoned it to be a dab. It stopped the leaking.

I've been inside a couple PS gears of the early w126. There's plenty of rubber in there for that brake fluid to damage so I'd be reluctant to do this to a mercedes now but I'm not just trying to get by these days.

Yup sounds like a rack job in your future. At least on a diesel 210 those never came with 4matic, so it's right out in the open and looks to be a totally straightforward swap.

The rack on our 2008 ML went out with the same failure mode. We ended up having an indy replace it because it required dropping the transfer case to get it out. Something I didn't want to do on my back with the beast on stands.

Are you certain they are o-rings and not crush washers?

I see in the diagram for the steering rack two different "seal rings" that go on the banjo bolts for the fluid lines.
The one nearest the steering linkage is A0249977148
The one furthest from the steering linkage is A0239979148

Hey guys, I found a YOUTUBE video that someone else posted that shows exactly where my rack is leaking from..... please view it as it is only about 1 minute long....... this is EXACTLY where mine is leaking..... thanks!

https://www.youtube.com/watch?v=gSYKVkVgOvU

You might be lucky. It sure looks like a piece of rubber seal is poking out from behind the leaking banjo bolt in that video.

That is a different problem than our ML. Ours was leaking from the head where the steering wheel connects due to an internal seal failure.

You will need a decent E-torx socket to remove this banjo bolt. Don't get the cheap set from HF, go to Amazon and look for a US made set from Lisle. About double the price of the HF set ($30 vs $15) but the sockets actually fit on the bolt heads, unlike the Chinese HF copy sockets.

Yep, that's where mine was leaking from (although mine wasn't that bad).

Do you know the approximate leak rate? If it's slow enough, you've got nothing to lose by trying the Lucas product.

I'd really like to fix it as it seems ridiculous to replace a whole steering rack due to replaceable seals or o-rings.... The problem I am having is locating the proper part numbers for the replacement parts...... If anyone knows please post the information

I'll be interested to hear if you're able to do it. I forget all the details since it's been a few years...but I remember bumping up against the same issue and concluding that I should just replace the rack.

Ah, that's a different fitting than what I provided previously. For these two fittings, the "seal ring" part numbers are N007603014102 and N007603016105. In my experience, MB uses the term "seal ring" to refer to a crush washer and not a rubber part. If that's the case, the rubber part may indeed be part of the steering rack, and not available individually under an MB part number.


Attachment 143399

You should check these parts. There is an o ring listed that might be the part you are looking for:

1999 Mercedes-Benz E300 Turbodiesel Sedan - Steering System - Page 1

Hi guys...... thanks for all of the input and responses..... Based upon what I'm reading here it appears that the best course of action is to first try the Lucas Stop Leak and plan to replace the steering rack, as attempting to reseal the leaking banjo bolt area is an effort in futility. What blows me away, and my perception may be flawed, is that removing the banjo bolts looks fairly easy to do!

jay_bob...... I sold my ML500 mainly because the steering rack went out on it....It had 240,000 miles on it and ran flawlessly..... it was a limited edition with more bells and whistles than the stock MLs....... I used to blow hot cars off the grid with that beast!!! Amazing how powerful that vehicle is!..... I once took it off road, had the driver's side front tire about 2 feet off the ground and that thing crabbed up that hill like it was nothing!

Just to give you a frame of reference, I was losing fluid at the rate of max to min level mark over the course of 100 miles. After using the Lucas product, I lost the same amount over 1500 miles. Now, a few years later, sometimes it seems as if the leak has stopped altogether, sometimes I find that I have to add a little fluid. But it's certainly an inconsequential issue now.