qaz393

your brake pads durability is mainly determined by your driving style/habits.

I would definately get the brake flush done at 2 years due to warranty purposes.

your rotors will need to be replaced if they have thickness variation or are too thin. the wear tolerance for the rotors are 2.5mm total. its better to be safe than to cheap out.

front rotors are normally 28MM thick and needs to be 25.4MM min.
rear are 10mm think and needs to be 8.3MM thick.

here is the specs for USA C300. (this does not apply to canadian C300. dont know about rest of world)

Eickecc

Sorry...misread.

Glyn M Ruck

Not misread - changed!

Glyn M Ruck

Thank you for a useful post. Have you checked whether Centric's numbers agree with the WIS?

qaz393

what is WIS??? they are probably very close. there number looks reasonable when looking at the brake specs from my other cars. (i have official manual for those ones). Id like to see what brembo has to say about the thickness and stuff XD.

its probably within .1MM of each otherr because i am 100% sure that thte front rotors are not 27.9 but 28MM...

Glyn M Ruck

WIS = MB "Workshop Information System" - the dealer's technical bible. Remember that Brembo manufactures for Benz.

Doanster

BTW, Stoptech is now a division of Centric, i.e. I don't believe they were born from the get-go out of Centric. Same thing for Power Slot. Not to say that Centric parts aren't fine/good to use, but I wouldn't just use that logic as your major purchasing decision. Centric's core business is being an OEM parts supplier. Have you found actual drilled front rotors from them? How much $$ were they if so?
Also, another myth is that Brembo by default is mucho expensive. For BBKs (many-pot calipers and multi-piece rotors) that's certainly true, but I do recall buying plane-jain Brembo rotors for my other cars throughout the years for the same price as any other brand.
At the end of the day, rotors are just hunks of metal, so unless the manufacturing process had extremely low quaility control, you're gonna be fine with whatever you end up choosing.
Pads? Well, that's a whole 'nuther debate and depends on what you're after...

qaz393

the stock design is garbage. the right and left rotor are the same and have directional vane. this means the vented vain are curved. One rotor blow air outward and one rotor blow air inwards.

poswerslot or stoptech offer a drilled rotor with specific left and right side design so that each rotor can blow hot air towards the outside.

for pads, what ever doesnt dust the most and cost the best will do the job. also no noise.

Doanster

I had actually brought up the fact that the stock rotors did not differentiate between left/right in a different thread, but outside of full competition settings, do you really think it'll make a difference? Also, the air isn't blown in or out, rather front vs back, which again, has no affect, IMO. The rotor is still cooled. Regarding Stoptech/Power Slot, no argument there. Both are great rotors. I thought you were talking about Centric specifically.

Also, you say that the stock design is garbage and are worrying about which direction the air blows, but then when it comes to pads, which are the more important piece of the braking puzzle, you say whatever costs the least, dusts the least, and is quiet is what you're after?

I will always choose a pad the provides the best (for my tastes!) stopping power and will live with having to wash the car more often to both clean and get rid of the squeaks. Granted, I don't want a pad that will chew up the rotors in 5k miles, but you get the idea.

Glyn M Ruck

My intention is not to knock Stoptech. I think their products & advice are good. But get one thing straight. There is nothing wrong with the Benz OE parts. They are excellent & were designed for a specific brake feel & bite & performance across broad ambient conditions. Apart from dust they do an excellent job. In day to day driving no pad feels as controlled in bite as the OE. They are also quiet!

qaz393

Benz OE is great, but they just have that design flaw of using same rotors left and right. I think most benz today, including AMG does use same left and right rotor. i personally see this as a flaw because we pay good money for our cars. why cant they be better as at the small detail.


other than that, most of the time, there is nothing wrong with OE stuff.

Glyn M Ruck

I was involved in a recent test on Benz with a new Ferodo Ceramic pad. The temperatures from left to right front under all conditions were as close to identical as not to matter one iota. So who cares which way the rotors pump air. Temperature control is all that matters.

qaz393

Benz OE is great, but they just have that design flaw of using same rotors left and right. I think most benz today, including AMG does use same left and right rotor. i personally see this as a flaw because we pay good money for our cars. why cant they be better as at the small detail.


other than that, most of the time, there is nothing wrong with OE stuff.

Glyn M Ruck

Repeating yourself now! I suggest you cease to be gullible & not believe all the marketing hype.

Just to put things into perspective. Not a single American braking component company is represented in South Africa. The odd Hawk pad finds it's way here & are considered to be crap.

The most popular pads & rotors here in the general consumer market are Ferodo (made here) & Ate (Alfred Teves - made here & imported) & probably EBC. All the rest are European with some Japanese. Of course Brembo is here.

Much of this is to support Benz, BMW, VW/Audi, Toyota, Nissan, Opel etc who all have plants here & build cars here. 99% of these cars in South Africa run OE brakes due to all being under Mobilodrive/Motorplan here. SA consumes over 66% of the number of Benz cars sold in the US every year & BMW holds it's highest market share of any global market in SA - even higher than their German MS - so we are not a small market for these guys. This is remarkable for a country with just over 50 million people.

We have no trouble stopping anything from busses & trucks to passenger cars & race cars & motorcycles in this racing mad country. We travel a lot faster on the open road here than people do on US Interstates. This is nothing to be proud of as we have a horrendous death toll on our roads. Very few of our poor accident statistics have anything to do with brakes. When they do it is almost always due to bad maintenance of brakes on open road coaches.

Don't make a big issue of brakes. They were well sorted out by the OEMs years ago. There has not been a decent development in braking since ABS. Most things today are tack-on's to ABS - even disc/rotor wiping systems are really old hat. Stoptech is small fry in global terms.

Carsy

While we are on pads & rotors !.

A question I have previously asked, why my rotors ( on current wear) will be worn below specs before the pads are 50 %.?

I can't really get my head around the answer of it being caused by the way I drive . ie with anticipation & light aplication.

The OEM pads under my conditions are obviously too hard for the rotors.

qaz393

ive heard light application can cause brakes to overheat. did you measured the rotor thickness or was this just an estimate?

Glyn M Ruck

JC - I think you should measure your own rotors to confirm that this is in fact true using WIS recommended min thickness. The Benz rotors are not the hardest around. They are spec'ed to work with the OE pad for optimal performance. We have postulated that the rotor wiping feature might accelerate wear. Your situation is certainly not typical. The OE pads are not particularly hard. If your present rotor wear rate is accurate I hate to think what ceramic pads would do to them. There is nothing peculiar about brakes on diesel models & we have plenty of them here & your condition is not typical. The US saw a bad batch of soft pads on the rear of W204's. Maybe one of the OE suppliers has screwed up?? I think the first step is to mic your own rotors. Pity you did not mic them new but who would ever do that.

Glyn M Ruck

Another thought - next time you visit your dealer, take your mic with you. Ask the spares dept. to pull a new rotor for your car & measure it new. I would like to get to the bottom of this.

qaz393

carsy drives a C200, might be even smaller than the C300 USA/C250 Canada.....

i hate how many variation the C-Class has.....

Glyn M Ruck

JC drives a C220 CDi

qaz393

ya i realized. anyways, it could be the same, but too hard to tell. maybe the EBC (UK site) has more model than most. too lazy to search right now.

Carsy

Glyn & qaz,

The front rotors were 28mm when new. Rears (solid) 10mm new .

At the 50,000 km inspection:- The front rotors measured 27 mm.Limit 25.4mm

-The rear rotors measured 9 mm. Limit 8.3.mm


Thickness left on front pads inner/outer average=11.6mm from 13mm

Thickness left on rear pads inner/outer average = 10.25mm from 12mm

At the current wear rate of wear the :-

Front rotors will be at limits when the pads are still 72%.

Rear rotors will be at limits when pads are still 75%.

So at present wear rate I will need to change the rear rotors at 85,000 km & the fronts at 130,000km.

Disappointing when considering the light use.

Glyn M Ruck

JC - The new spec you are taking from the book (WIS) I presume - you have the service CD/or WIS IIRC? That's why I wanted you to check that new ones were at least as stated. Wow - you are a light braker but no doubt little city driving. Open road to inter urban can give huge pad life.

That said - If I compute my C240 just sold. City to intra urban car - lots of braking but modest. Enough braking to even front & rear tyre wear to almost identical at centre of tread. Standard sliding calipers

Front rotors would have needed changing by 130,000Km's with 3 sets of OE pads but some life left on pads.

Rear rotors at a guess would have gone 160,000Km with 1 pad change and a lot of meat on the pads remaining.

I did drive with a caliper over return situation on the rear for a while (about 20,000Km) after the first front pad change before correcting by bleeding & stomping on the brakes to regain pedal height & feel. This might have protected my rears slightly for a while.

Wear is very service orientated. I would say your front rotor life is in the ball park. Your rear is unusual.

It's possible that your very light braking is tending to glaze your pads & protect them a little vs the rotors.

I will keep an eye on the C240 & report. Now owned by a close friend.

Carsy

Thanks Glyn.

I think the glazing theory could be correct.

Comparing our tyre wear .My rears were at wear strip at 34,000 km.

The fronts were 2.75 mm above wear strip so should have made around 60,000km if not for tyre splitting failure .

I consider this normal for my rear wheel drives. The old Pugs always achieved 60,000km on the front & 40,000 on the rear.Same country driving.

Glyn M Ruck

Yes. Your tyre wear makes sense for no rotation. Even though you have a moderate driving style the diesel has good low down torque & will be a little heavy on rear tyres. It takes a lot of in-town braking to even the wear. Benz cars are not particularly light on tyres.