E210 Brake pedal sometimes goes to floor!

[alan ainsworth]

Hi people, got an interesting one here on an E210, our customer complains that once or twice the brake pedal has gone straight to the floor. The master cylinder has been changed and the whole braking system checked by a MB stealership. Any ideas?

 

[Hilton]

Hi,

This is heartening, along with corrosion !

I remember that a member called Olaf Maxwell had experienced something like this. Maybe he will respond.

Grateful for any info / tips on how to use parachute etc....

Chris

 

[jberks]

I have heard of a couple of cases of something fracturing -I think its the cast connection block on top of the abs unit, I believe this was what Olaf experienced. I assume that this is not the case as you would have found it. (covered in brake fluid!)
Daft question, but if there's nothing to find,
It's not the BAS kicking in is it?
The pedal appears to go down to the floor but its the opposite of no brakes, as the wheels lock up (until the abs sorts it out). Does the car stop or not?

I suggest a bed sheet attached to the inside of the boot lid. Pull the boot lid open switch and hey presto, instant parachute! (yes I know it doesn't work!)

 

[watsone91]

This can be caused by a binding caliper the heat build up boils the brake fluid and any water in the system boils with it causing a bubble of steam in the system the first press of the brake pedal compress the steam bubble and the pedal goes to the floor .

Very dangerous run the car for a while not touching the brakes stop slowly and touch each caliper cautiously to find the culprit cheers

 

[OlafMaxwell]

Brakes to the floor.

Am sorry to hear of this problem again.

In my case the first failure happend I think about 65k. I was in England driving on M6 when warning came on and brake pedal went soft. I pulled into services at Corley and looked at the wheels and flexible pipes to see if there was any leakage. However I found none, then moved car and and saw brake fuid on the ground. The pipes coming from the cast alloy unit were all pumping put brake fluid so both circuits were failing. Normally cars have two circuits so that if you get failure in one the other still works. Not so with MB. The ABS unit pumps your brake fluid out on both systems and leaves you with no brakes.

MB in Coventry replaced the ABS unit and in fairness to MB the Mobilo Life and replacement was faultless. THe car was out of warranty but a 50% parts goodwill did not go astray. However the fault occurred again 5 months later. Brake pedal to the floor again. MB in Ireland [owned by MB UK I believe] refused any Mobilo Life despite the repair carrying a two year Pan European warranty.

I did a little more research due to the manner MB in Ireland treated this issue. There is a problem with the E class W210 brakes, I know of quite a few other cars [W210] that have suffered sudden and unexepcted brake failure. Many years ago when I had Fiats regularly replaced master cylinders and replaced seals in the master cylinders. When these seals failed you got pedal to floor, no brakes but also no leaking brake fluid and not tell tale signs. I am convinced there is a problem with either the ABS pump or the ESP in that fluid may not be leaking out of the system but is getting passed seals or being recirculated in some way possibly by a faulty pump. I do not know how the front/rear load/pressure proportioning works on these cars and if this is done by the ABS/ESP unit then I think it might be suspect.

As a matter of curiosity did you ever have to replace the oil level sensor unit/sender unit?

 

[SUE.]

This can be caused by a binding caliper the heat build up boils the brake fluid and any water in the system boils with it causing a bubble of steam in the system the first press of the brake pedal compress the steam bubble and the pedal goes to the floor .

Very dangerous run the car for a while not touching the brakes stop slowly and touch each caliper cautiously to find the culprit cheers

I think you mean brake fade,when the fluid gets too warm.

 

[Hilton]

Brake failures..

Hi OlafMaxwell,

I guess I am slightly reassured that you at least got a failure indication which warned you of the problem. What failure indication was displayed on the first event and did you get a warning on the second event ? Did MB ever admit that their design included a single point failure in the brake system ?

I shall certainly take brake warnings more seriously, even though the first one I got was traced to a the failure of the brake switch.

 

[190]

Here,s a link on brake fade.

http://www.h-e-l.co.uk/HEL_Performance_Brake_Doctor_Brake_Fade.htm

 

[OlafMaxwell]

Lack of warning.

Just to clear one thing, the only warning I got was low brake fluid. I had checked the levels about 300 miles earlier and did not notice anything amiss. However, before I even got to services the warning changed to BAS failure and the pedal went soft. However, before the warning came up I had noticed a slight change in the brake pedal feel and was alert to a potential problem. From warning to total failure was only about 10 miles.

As for dealing with MB...impossible, they did not want to know.

I drove motor bikes for many years and know it was not a fluid problem or a brake pad problem.

When the problem came up the second time I just pulled over and called breakdown. A look underneath confirmed brake fluid leaking from same place again.....now I make sure to check it every time I top up the windscreen washer.

I just got the brakes done in my Peugeot 405 before Christmas, new brake pipes, new brake fluid etc......Merc is off road yet again......waited since last August for them to respond about rust on the doors. Two weeks ago I get a phone call....we will replace the doors, need the car on Monday. They deferred it a week and collected car last Monday. Thursday evening...... Houston we got a problem.....doors are all sprayed, ready to be fitted, old doors off, doors cut to remove glass and fittings....now all we have to do is fit the new doors........oops...no one checked to see if they were the right doors..........

 

[MB partsman]

Houston we got a problem.....doors are all sprayed, ready to be fitted, old doors off, doors cut to remove glass and fittings....now all we have to do is fit the new doors........oops...no one checked to see if they were the right doors..........[/QUOTE]
why the hell have they CUT the doors for? have they never heard of stripping the doors down?

 

[Hilton]

Doors to be replaced..

Hi OlafMaxwell,
Interested to hear that MB approved door replacement in the current climate - excellent news! My local bodyshop would only recommend repair. Was the corrosion very bad and how widespread was it on the doors ? Shame about the wrong doors and I too am curious why they would cut the original doors to remove trim !

 

[OlafMaxwell]

Hi MB Partsman...

Over here I found MB to be unprofessional especially in their service etc.....

So, their warranty manager once said to me he was 'Unable to telephone a dealer' to quote verbatim.

Now you get this picture of Gullivers Travels....MB owners, held hostage, tied down with wires anchored into the ground. All around, little men, all armed with chainsaws, swarming all over MB car, attacking the doors to cut the top frames off so they can get the glass out a little more easily. Meanwhile back in the ranch on the next island I mean paintshop another swarm of little men are busy unwrapping and painting doors.

Why did they replace the doors? Because of how they treated me last year they had to agree to honour their Mobilo warranty which is unambiguous when it comes to rust.