Aussie_E350_Wag

Hey guys,

Haven't posted for a while as I've not had any issues,

The other day I got a brake wear warning on the dash, car has 107,000klm (66,000miles) so it's been a good run and value for money.

Now, my massive issue that's killing me!!

I removed all 4 discs and gave them to a trusted local shop to skim so they were nice and clean for the new pads.

My dumb **** removed the front disc AND hubs by accident so needed to remove the inner seal and both tapered bearings...and a fist sized ball of neon green grease!

Not a worry just messy to do...stupid still didn't notice the screw holding the disc into the hub 🥴🥴

My trusted friend at the brake shop laughed his **** off at me taking the whole hub off...cheers mate 👍🏻

He did a great job, both pairs looked new so I set about installing them with new pads and wear indicators.

Slow and steady to make sure it's all fine.

Got the car finished and back on the ground....

Went for a gentle drive down our workshop areas long driveway and suddenly every alarm and warning possible started to fill the dash, lights and scrolling words on dash saying basically every single safety feature is now disabled????

I drove around the block, the roads wet and I had no ABS no Stability No Traction Control, zero nothing, I could easily lock the front brakes and do long power skids as the single back wheel spun freely on the wet road??

I went back to the shop, got our Snap-On Scan Tool

44 errors came up after a complete scan,

I read them and found that the right front Speed Sensor was faulty so I guaged this to be the root cause of most of all the other errors as these systems rely on accurate information from each wheels speed and direction to make critical decisions.

I pulled the front wheels and checked both ABS censors inside the spindles, both looked fine, a bit of grease on one but no damage or coved in iron filings...looked normal.

Reassembled it and rescanned it and cleared it again, went for a quick drive and the same Christmas lights came up on the dash!!
With the Snap-On Scan Tool I was able to scan all 4 wheel sensors at once and driving back and forth in our driveway I could see all 4 sensors sending identical data for each wheel.speed???

Based on that it seems that the sensors are fine but the main BCM/ECU doesn't think so???

I am completely lost as to what's happening as it makes no sense for such a simple job to leave a car like it's a 1970's model with seat belts and no other safety systems????

Can anyone suggest what I do next please?

Left Coast Geek

there's rarely enough left on these rotors to skim if they are worn.

JettaRed

iTrader: (1)

Maybe DIY is not in your future! I didn't know people still turn rotors anymore. Seems like a waste of money. Maybe if I owned a Hyundai, but certainly not on a Mercedes.

Rotor thickness may be insufficient, as Lefty said above. Or your tone ring(s) may have been damaged when removing the hubs. (By the way, how did you set the torque when reinstalling the hubs?). You may now need to put new rotors on and maybe new front wheel hubs.

You should get yourself a proper Mercedes-specific scan tool so you are not reliant on someone else's availability to scan your car. If you don't want to spend the money on an SDS/XENTRY setup, I recommend the LAUNCH Creader Elite 2.0 BENZ. Very affordable, very powerful.

S-Prihadi

Yours is a RWD and not 4matic, it seems.

The ABS/ESP module has what we call substituted value.
So if one of the wheel speed sensor goes bad, the DTC will be produced and ABS/ESP will not be active, but when you read the wheel speed, the bad one will look like it has a signal.
That is substituted value.
Since ABPS/ESP is very important, other modules in the same CAN BUS will make the report too, hence so many DTCs and most will be very similar actualy.

Also Snap On is probably not so good for Mercedes cars, you by now must have you own scanner.
The Launch baby sized one version 2.0 which is MB/BMW specific is a good one bang for the buck. Or you can get the Benz only for a bit less. We now call this one version 1.0.

When you remove the front wheel bearing hub, how did you tightened it back ? Did you follow the WIS ?

The seal item 40, is also a pulse generator for the wheel speed sensor.
If you did not re-assemble your wheel hub assy INTERNALS properly, I am afraid the air gap is now too much and hence sensor is not reading the pulse wheel.
Also there is a proper adjustment for the wheel bearing overall play, which is very small at 0.01mm only




I never removed my wheel hub, all I do is adjust my front wheel bearing play.
See here : https://mbworld.org/forums/e-class-w...ent-again.html

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You can test the actual signal out of the wheel speed sensor, but you need a scope for it.
Also you must reset the DTC every time , because some module will cut power to the sensor when it detects problem/defect.

If Left and Right sensor can be swapped, swap it first and see if the DTC follows the swap.
The sensor is low cost. Good thing.


Good luck......

S-Prihadi

One more thing. Since you skim-med your disc rotor.....
There is a writing machined on your disc rotor for the minimum thickness.
Make sure yours is withing spec, as safety concern.
The disc rotor only has 1.8 to 2 mm thickness life, depending on the size of the disc rotor diameter.

My front one minimum thickness is 30mm. I am using a 344mm diameter disc rotor. New is 32mm.

Aussie_E350_Wag

There was plenty left and it was just to clean the surface for new pads.

Aussie_E350_Wag

I have a fully built laptop from Benz Ninja, I also don't see the need to waste $500+ on new less quality rotors when these are within their serviceable life, I'd worked a 10hr day when I started doing this as I needed the car and my friend only called to say the rotors were ready at 4:45pm very late in the day.

Aussie_E350_Wag

Many thanks for your help, I tightened by hand making sure they didn't bind, I don't have any way to measure as they are such an unusual locking system not a traditional nut and cage setup.

What does the WIS say?

Is the dust seal on the inside of the hub part of the sensor system?

JettaRed

iTrader: (1)

This is how you set the hub nut on a Mercedes wheel hub.

JettaRed

iTrader: (1)

Awesome! Did you ask Peter for help diagnosing you problem?

I agree! No one should waste $500+ (even Aussie dollars). However back in my working days we had a saying, “If you don’t have the time (or money) to do some right, what makes you think you’ll have time (or money) to do it over?”

S-Prihadi

So Aussie, what actually went wrong ? and I hope your ABS is OK now.

hyperion667

Typical MB making it a PITA to DIY.
Good luck to ya