service brake warning

[carabind]

on my E211 (2005) , I had a warning flash up on the trip computer.
"warning - service brake - visit workshop" It stayed for an hour yesterday
but disappeared after I left it for 10 mins

Any idea what might trigger this ? the car has done 36 k miles and the pads were checked at 33k and I was told they were half worn. Would low brake fluid trigger this ? If so, perhaps the worn pads have created enough space at the calipers to use enough fluid there to be low at the resevior?

or is there a deeper problem ? (the SBC is still working by the way)

 

[star]

Could be a number of reasons, the most common is tha the pump has reached the end of its sevice life or took too long to reach op pressure.

 

[carabind]

the car is not even three years old? and 95% used on motoways, so lets assume its lighly used and that it may not be the pump? Might low fluid level casued it ? If so I will top up and it will go away?

 

[star]

the car is not even three years old? and 95% used on motoways, so lets assume its lighly used and that it may not be the pump? Might low fluid level casued it ? If so I will top up and it will go away?

might do, worth a try but never had it before tho. easier to get it checked on a star after that. shouldn't take chances with brakes.

 

[carabind]

well I'll stick some fluid in it now , if it flashes up again (it's gone away and showing no malfunctions) I'll take it into the the dealer immediately, it is under warranty till september anyway

so plenty of time to get a new pump out of them if I need one !

 

[carabind]

well fluid top up seems to have banished the warning light today anyway. Sort of makes sense, to me at least

 

[brandwooddixon]

Best check to see where that fluid has gone I think.

 

[seabadger]

Service Brake - warning in speedo

Interested to read this thread - I am having the same problem.

The fault warning invariably clears when I switch off and restart, however it keeps coming back. Had the problem for several weeks now.

I have associated it with cold weather? It seems to happen more frequently in cold weather.

The SBC pump does seems to be operating a lot more but I have changed my journey to work and there's a lot more stop/start. Sometimes the SBC hold needs a lot of pressure on the pedal especially on steep hills to get it to hold.

There's no problem with the Brake fluid level and I changed all pads and discs last year.

Star's first response was the pump may be suspect.

Is replacement a difficult DIY job?

 

[star]

yes, theres a special process in bleeding the sytem afterwards, on a star machine.

 

[Ian Brown]

the car is not even three years old? and 95% used on motoways, so lets assume its lighly used and that it may not be the pump? Might low fluid level casued it ? If so I will top up and it will go away?

Why not check the fluid and see......:idea:

 

[seabadger]

W211 - Service Brake! Visit Workshop! -warning in speedo.

Thanks for the suggestions.

Like carabind I first checked the brake fluid level,

When I changed the pads and discs last year I left it overfull and now its about at the top of the mark.

The idea that the pump isn't replenishing the system fast enough sounds plausible. A couple of times the SBC hold hasn't come on - you notice on steep hills when you slip back! and I've waited for the SBC hold light to come on pressing hard on the pedal.

Will the fault be registered in the memory and will this code explain what the specific problem is?

Changing the pump does sound like fairly major surgery but isn't the SBC pump on a seperate system and not connected to the hydraulic braking system? If SBC fails the brakes are still supposed to work - the pedal goes down further and you have to press harder.

I'll be very disappointed if I have to take it in to do a repair but I may need to get the fault code read.

 

[StevieBox]

I took my E320 CDi 53 plate to Mercedes only yesterday, same service brake warning.
They ran some tests and decided that the brake pump needs replacing, About £1200 with 5 hours in the workshop including replacing the brake fluid, there must be a issue with the system as Mercedes are going to pay for it!!

They are also replacing the switch on the brake pedal

hope this helps

 

[seabadger]

Thanks StevieBox. Good to get a response even if it's not good news.

I haven't taken it in to get the fault codes read yet, but I've quizzed a dealer about the possibilities. Possible causes too numerous to mention including low brake fluid, worn pads, and brake light switch etc - only remedy is to bring the car in and put it on the Star Diagnostics.......

I have a bad feeling that it is my SBC pump that's on the way out, like yours.

Interestingly an MB dealer near me told me that the SBC pump is effectively a consumable as each unit is good for 365,000 brake pedal depressions then its a new one. I wouldn't hold him to getting the exact number of brake pedal depressions right -off the top of his head - but the message is clear.

I read on the forum that it may be replaced by MB foc but this dealer categorically denied this.

I wonder why yours is being paid for by MB? How many miles have you done?

Have you had any other symptoms? I am having difficulty getting the SBC Hold to come on when stopped on steep hills. It needs a lot of pressure on the pedal.

 

[StevieBox]

Hi Seabadger

My car has done 38000 miles,
No other symptoms, just the service brake warning.

I didn't question the dealer at the time, was just pleased they were going to pay for it.

I am taking it to the garage wed evening for the to carryout the work on Thurs so I will have a dig around as to why they so readily proposed to pay the bill.


Cheers

 

[Steve Taxi]

Seabadger, we also had an SBC pump replaced FOC two weeks ago, 160k miles 04reg after the same fault warning.

 

[Ellsy Tanners]

If mb tell you that it is not covered ask them to do a good will claim on your behalf, then ask the see the printed results of this, I would be very suprised if they say no.

 

[seabadger]

Hi StevieBox - Hope you get it sorted out. I would be pretty pleased as well if MB paid. However with only 38,000 on the clock you wouldn't expect anything like this happening!

Hi Steve Taxi, Looks as if this gets to be a regular thing as these cars age? You must pleased it didn't set you back £1200 as reported by Steviebox above. My man reckoned the part is £600 ish and with 5 hours labour - QED? I have to say 5 hours seems a lot?

Hi Ellsy - MB have a name for this 'after warranty' good-will business. Can't remember it's name? I think they can do it on line? Roughly it works out - up to 3 years old FOC (on warranty), 4 years 50% discount, 5 years 25% discount, 6 years old zilch. It's modified by mileage, condition and how often you pay for services. My daughter's A class rear trailing arm bushes wore out before the original back tyres needed changing (at approx 45,000 miles). It's a workshop job and MB change the whole trailing arm. We asked - the car was 6 years - we got zilch! It cost us plenty.

I live in hope. We did a long trip to Brighton and back this weekend and the warning never came up. I checked the wear sensors as well last week. It's 26,000 miles since I replaced the front pads and yes I have just started to chew through the near side sensor - the pad is about half worn. The off side has the pad worn out/low pad sensor - this has plenty to go yet. The Service Brake! Visit Workshop! warning never came on when I reached this stage of pad wear at around 65,000 miles. Hence my discomfort.

Thanks for your messages.

Cheers
Seabadger

 

[Ellsy Tanners]

Hi seabadger,

I cant say to much but trust me, if its the pump, its different, get them to make a good will claim.

Although in your case, it most likely isnt the pump as it would be on and stay on. possible brake light switch in your case.

 

[seabadger]

Thanks for the tip Ellsy.
The fault hasn't come up for a week now (851 miles). I'll get a new brake light switch and put it on. This will eliminate another possible fault source at minimal cost.
Cheers.

 

[type49]

I agree with Ellsy. Try another dealer if you have to. MB WILL pay for a new pump wether in warranty or not. I do not know or any where the customer has had to pay any costs. A goodwill claim should not be refused on an SBC pump.