SL 55 AMG - Awful Brakes - any ideas ?

[TimNaughton]

Ah thanks for the info. The Brake fluid was changed by the Merc main dealer in Harrogate at the last service in January 10 , and I thought it was interesting that they thought new discs and pads would only 'part cure' the brake problem. Everything seems over complicated on this car - I love it but never had anything quite as unreliable. So far in 6 months had £2,500 of repairs done ( Exluding service Mostly on extended warrenty from selling dealer - thank goodness) and now I have a very noisy fuel pump - it seems never ending.

 

[TimNaughton]

Great info about pads. Thank you. Its really intersting to get feed back from real enthusiasts and much appreciated. I will look up all those makes !

 

[TimNaughton]

Hi Will, Yes I was suprised about the disc and brake prices - but they seem the wrong way round to me -- the Merc Discs are £52.00 each plus Vat and the pads £209.00 an axel plus VAT. Been trying to get Black Diamond discs- similar price but no chance as the SL55 discs are huge and not high demand. I am more used to the the brake travel now - but it is off putting in such a high performance car when things are really steaming and there is an urgent need to stop. Thanks for the advice. Tim

 

[marty359]

My brake pedal has quite alot of travel in it but will still stop on a dime,Its always done it even after new discs/pads and ive had the brake fluid changed 3 times since ive had the car after trackdays and high speed runs,still the same.

Then when i drive the wifes mini cooper D the brakes nearly send me through the windscreen.

Marty

 

[bdabdabeav]

hi. did you bleed the brakes yourself? Your vehicle has SBC. standing for sensotronic brake control. the braking system is servoless meaning all your braking is amplified through the control unit via solenoids and valves. you need to bleed it via STAR and perform an air test afterwards with STAR. only mb dealers can perform this unless an indy has the software. If it was faulty a message would have come up on your display but the SBC units do have a threshold limit if they are updated. Something like 300,000 brake pedal depresses. After this they will be replaced through goodwill at no cost to yourself. book it in with your nearest dealer and get them to check the operating time of the SBC and get them bled. Sl brakes are meant to be some of the best available and iv never had any worries when driving 55's from their brakes.
hope this helps

 

[bdabdabeav]

btw the discs are £520 each plus vat not £52!

 

[Will]

btw the discs are £520 each plus vat not £52!

Sounds more like it - the discs on my CLK are a couple of hundred quid a side - couldn't see SL55 AMG discs being fifty quid!

Will

 

[matt17081]

just a quick chec that you can do from the driver seat, with the engine off press the brakes a few times so there is no servo assistance and you have a solid pedel, then take your foor off the brakes and wait about 1 min and press the pedel again if the pedel travel further than it did the last time you have probably got air in the lines somehow then again with the engine off predd down hard on the pedel and see of the pedel is "sinking" this would indicate a leak, but you would also have a "damp patch" on the floor and would need to be constantly topping up the fluid so is unlikely, failing that get the car to an mot testing station where they can put it onto the rollers and see exactly what the braking effect on each wheel is you may just have a caliper that has started to partiall seize up. but GET IT CHECKED OUT ASAP !!!
brakes - cheap
bodywork - expensive
life - PRICELESS !!

 

[TimNaughton]

Thanks for that. Perhaps I just have to get used to them. I have not been able to drive it much since I bought it in October last year - due to icy roads and too much power - so perhaps i must forget the hot hatch brakes and get used to them.

 

[TimNaughton]

Ah thanks - Brilliant explanation of the brakes. I had no idea. The MD dealer put new fluid in the system at the service in January, 36,000 miles. Perhaps it needs checking again. thank you.

 

[TimNaughton]

Actually got the quote here - so i better take the MB dealer up on it before they change their minds !!

 

[TimNaughton]

Thanks Matt- top advice and so true !!

 

[Adam230K]

Ok there seems to be alot of advice here, some of which sound a little OTT imo.

What you need to do is (if you want to be certain), on a long piece of straight quite road somewhere, take note of how long it takes you to get from 70-0. And then maybe compare that to book times, or look for a review on the SL55 on the internet to benchmark it.

I distinctly remember when going from my C230K to the 540i, that the 540i's brakes required more push til they got working, like you describe, more spongy, but my 230K had stainless steel hoses. But without a shred of doubt, the 540i definately stops alot faster than the 230k when I stomp on the brakes, its so so obvious.

Just my 2p.

 

[BlackC55]

just a quick chec that you can do from the driver seat, with the engine off press the brakes a few times so there is no servo assistance and you have a solid pedel, then take your foor off the brakes and wait about 1 min and press the pedel again if the pedel travel further than it did the last time you have probably got air in the lines somehow then again with the engine off predd down hard on the pedel and see of the pedel is "sinking" this would indicate a leak, but you would also have a "damp patch" on the floor and would need to be constantly topping up the fluid so is unlikely, failing that get the car to an mot testing station where they can put it onto the rollers and see exactly what the braking effect on each wheel is you may just have a caliper that has started to partiall seize up. but GET IT CHECKED OUT ASAP !!!
brakes - cheap
bodywork - expensive
life - PRICELESS !!

This will not work with SBC brakes. It is a fly-by-wire system.

If you have air in the system it has not been bled correctly with the Star. There is a test after a brake bleed has been done with the Star which it MUST pass to enable the system to compete the bleed process. If it does not pass you have to bleed again.

Can I suggest that a road test is performed by a MB technicain (like me) to see if your system is normal.