Where's the H#&& is it leaking from? HELP! - PeachParts Mercedes-Benz Forum

KenF · #1 10-15-2010, 03:27 PM

I have a rather serious brake fluid leak. About 6 oz per mile!!

From on top everything is pristine and there absolutely no sign of a leak. So I crawl underneath, remove the tray and the steering box is absolutely soaked. The tray has fluid on it and it has obviously been dripping off the tray as I drive. So it looks like something above the steering box is leaking. (Hmm. it may be "spurting" from somewhere else - lot of stuff coming out from somewhere!!)

Question is Where the heck is it coming from and how do I get at it to repair it?

MattBelliveau · #2 10-15-2010, 03:40 PM

Bottom of the master cylinder? Cracked union in the same area?

KenF · #3 10-16-2010, 01:27 PM

Actually, everything seems dry there. There is bodywork under the servo (and master cylinder). It's really hard to get in there but I can't find any sign of a leak. I am beginning to think it is a line somewhere underneath that metal that is cracked and spurting fluid all over the steering box.

Trouble is that I can't get to it from up or down and I just don't know where to start!

Chainsaw??

Gilly · #4 10-16-2010, 03:46 PM

So is the brake fluid reservoir draining out? With that much fluid loss, it should be empty by now. Wondering if it is some other fluid like the power steering or self levelling oil.
If it's definitely brake fluid, I believe your ABS pump is in that same area.
Gilly

KenF · #5 10-16-2010, 04:36 PM

Yeah, the reservoir is almost empty. The ABS/ASR is right in front of it - no sign of anything leaking - everything on top is clean as a whistle.

A couple of months ago I had a local "German car Specialist" (2 Square Auto for any Calgary readers) replace a corroded rear fuel line for me. He was supposed to replace both and it cot me $500!!!!!

After crawling underneath I realize that he only replaced one and he left the other one flapping out of the front bracket, so it is lose from the middle of the car to wherever!!! It disappears up behind the steering box so I am thinking that it has cracked wherever it is next supported.

Trouble is I just don't know how to get in there!

I find that one problem with MB is everything is categorized as "Engine" or "Body" and some thing don't fit into either! I usually use the 320E section of my discs for body but of course it is quite different when it comes to accessibility. There is MUCH more room in the 320E.

Gilly · #6 10-16-2010, 08:18 PM

Still more questions than answers:

Unsure what the car is that we're discussing.

The "other" fuel line I would assume is the vent line, for the charcoal canister. I think. Pretty $hitty though to pay $500 for both, which is over the top nuts, then they screw up and do 1/2 the job you (over)paid for.

Leaving us with the question, why is your brake system puking it's guts out.
I would proceed like this: Top it off, remember to get DOT 4 brake fluid, not the more-common DOT 3, have a helper mash on the brakes and look around with a flashlight trying to find the leak. You know the general area. Mostly up there the lines are attached to the inner frame rails and such. Wish I could offer more help. Drive it to Wisconsin and I'll take a look! Just get a 55 gal drum of DOT4!
Gilly

KenF · #7 10-16-2010, 09:15 PM

Thanks, and don't temp me Gilly! I've never been to Wisconsin!!

Sorry I didn't realize that that wasn't part of my profile. It's a 1993 400E

This car has ASR so I believe the 2nd line is the other brake. The ASR controls the rear brake individually (I'm not and expert) so I would imagine it has to have a discrete line to each.

Laying under the car there is just not a lot to see, I'll try again tomorrow, though.

Any idea how to get into that area? I mean like pull the dash, remove the steering wheel, disconnect all electrical, disconnect steering idle arm, unbolt steering box, lower and withdraw? Ouch!! That sounds like the car is going to the SCRAP YARD!!!

Gilly · #8 10-16-2010, 09:36 PM

Oh boy a 124 V8, lot's or room huh?
The only thing I can think of would be the lines themselves between the engine and frame rail. I'd try spotting the leak first, assuming it should be pretty obvious if it leaks that badly, just have a good light to look and have someone else step on the brake to help produce the leak. Worse case is you'd need to order a precut line from MB. Then shouldn't be too awful bad to replace it.
You're right, would be cheaper to fly ME there to fix it.

LOVE Canada, it's like the big 51st state we never had........ *ducks*

Gilly · #9 10-16-2010, 09:41 PM

And wanted to get a better handle on the location, are you saying near the left front corner of the engine, roughly, or more like the left rear corner of the engne, closer to the master cylinder? Pretty sure you'll find a line cracked or worn in to, wonder if the monkey-wrenches that did the fuel line (Singular!) screwed this up too. There are a few lines from the master to the abs pump and probably around there from the sounds of it. No huge deal though, you can just replace starting and ending where you can get access, splice in a line if you need to, or MB very likely sells the line precut and possibly even pre-bent.

KenF · #10 10-17-2010, 01:13 PM

Hey, Gilly, Canada would have been the 51 st state except that the US is still licking it's wounds from the last 2 times we defeated you guys

Stay your own side of the boarder or we'll whup you again! lol

I was watching a TV special yesterday - excerpts from the Montreal Comedy Festival - bashing Canada. Mostly Canadians but US, UK etc. One US comic says "we're all the same! We speak the same language, We both have armies - only difference is we (US) give ours guns!!!"

MB part I would guess $100-$150 i can take that but the 2-3 weeks delivery kinda stinks!!

The location seems to be in the general area below the master cylinder. But there's metal in between and no sign of a leak from on top. I am attaching 2 pics. One from underneath - you can see that there is no leak in the wheel well but there is a "general soaking" from inside of the frame, behind the Strut

The 2nd pic is from on top so you can see the top of the strut. As I said, everything is clean in here (though a bit dark on my pic.) There are 6 lines to/from the ABS/ASR; 2 go to the master cylinder and the other 4 quickly disappear somewhere! You can just see from the pic that the heat shield blends into the bodywork around the strut - it continues under the master cylinder for as far as I can feel. One line is fairly short and I guess feeds the nearest brake. the other 3 carry on around to back and below the master cylinder where I cannot see or feel.

I still have the problem of just where to start!! Pull the Master cylinder and servo? Maybe I could go in through the wheel well - remove the wheel and inner wheel well liner?? At least that might be easier (Then get out my Sawzall!!)

If somebody has some ideas where to start that would be most helpful.

RPM55 · #11 10-17-2010, 01:36 PM

Have you tried using a small mirror and flash light to look under the master cylinder? If I remember correctly there is a charging pump for the ASR system mounted under the master cylinder. There is a short section of hose connecting the brake reservoir to the pump. It is possible that the hose could be leaking.
The metal brake lines going to the rear of the car go down along the inside of the frame rail and are hidden/protected by a heat shield I believe. As you say there is not much room to work.

Good luck,Robert

KenF · #12 10-17-2010, 02:53 PM

As far as I can see there is a "floor" under that whole area which extends under the servo and attaches to the bulkhead. The Leak is obviously below that and I just can't see ANY WAY IN!!!

RPM55 · #13 10-17-2010, 03:16 PM

If you don't see any fluid on that "floor" then the leak is most likely from one of the metal brake lines going to the rear of the car. The lines come off of the ASR hydraulic unit and go down in the area of the steering box and follow along the frame rail. They are protected by heat shields in the area around the steering box and are next to impossible to see. If you have access to a lift you may be able to see them from underneath the car. I would think that if they have to be replaced it's going to be a major job.

Good luck,Robert

Gilly · #14 10-17-2010, 05:36 PM

I agree with all that. I'd try to find another shop that would at least help you locate the leak. I agree if the flat area under the brake junk is dry, probably inside the frame rail area. If you can hoist it with someone in the car to step on the brake pedal hard, you might have an easier time than just looking at the wet areas.
Gilly

KenF · #15 10-18-2010, 07:38 PM

If it was leaking into the servo (Booster) where would it come out?