cgmike10

I had a similar problem. Use only original mb brakes. If that fails, go to an independent shop and get your rotors resurfaced, and original mb brakes put on. You will ge tthe job done for half the cost

SteveB

Why in the world would you want to install another set of factory pads when there are far better alternatives available?

cgmike10

mb brake pads are extra soft to allow you extra stopping ability while eliminating squeaking because they are inherently heavy cars.

Now, although aftermarket brakepads might fit, like other aftermarket parts there is always a downside.

Sure, aftermarket pads are cheaper, may come in different colors, have appealing names, or offer a low dust solution, they will make your brakes squeak like an 18 wheeler. Imagine, a 40k or more Benz that sounds like an 18 wheeler?

One of my cars is out of warranty, and as a result I thought I could save a few bucks by simply using aftermarket pads. BTW, this car is a CLK and it even sounded like an 18 wheeler. There is no such thing as better aftermarket pads.

Oooo, I forgot to mention, when you step on the brake with aftermarket pads, the car shakes violently. It feels like you hit turbulence on airplane.

Plus, the dealer wont install aftermarket pads if you go to the dealer, and, it wouldnt be impossible for the dealer to deny warranty claims because they could say that these aftermarket pads caused damage to the braking system. (this is possible, but not likely)

SteveB

That is like saying 'aftermarket' tires are bad too. "Aftermarket" is a mis-nomer anyway. I'm referring to using other than the OEM parts supplied with the vehicle.

Sure, if you go to K-Mart and have cheap tires installed, they're not going to be as good as what came on the car from the factory. However, there are many tires out there that are far better than stock, & the only reason the car didn't come with those is that they cost a lot more & would raise the price of the vehicle.

The same for brake pads. The pads from the factory are adequate. However, there are pads available that will stop far better than the stock pads. In addition to better stopping power, they'll fade less, wear longer, be less harsh on the rotors, & emit less dust. You just have to know what pads to use. I just bought a new ML500 & the first thing I did is take out the stock brake pads & throw them in the trash. They had 100 miles on them.

Some Pete Guy

Why, when your stopping distance is determined by your tires, not your pads?

I have no problem locking up the wheels on the ML with stock pads.

Amfung

SteveB,
What brand of aftermarket pads are you using ? I'm curious to see how long the aftermarket pads can last compared to OEM. I had to replace my rear pads at ~12K miles. My front pads are starting to squeak now at 14.5K miles.
A

SteveB

Fade resistance is the reason for better brakes.
You might be able to lock up the wheels when slamming on the brakes, but, can you do 2 or 3 high speed stops & still be able to lock up the wheels on stop #4?

SteveB

I'm using Rotex metallic pads. I had a set on my ML320 for 20,000 miles which still had over 50% left when I sold it. I installed a set on my ML500, and on my Boxster.

Some Pete Guy

Fade resistance is an issue however my question was directed at what might be the claim that is seen all too often about shorter stopping distances.

FWIW, the answer to your question is yes, based upon my driving experience in a ML 430 and an ML 55.

I would be more concerned about fade due to boiling fluid rather than pad composition.

I haven't been able to boil the fluid, yet.

SteveB

Why is it that your ML430 & ML55 (&my ML500) came with better (bigger rotors, fixed 4 piston calipers) brakes than the ML320?
While it's true that ultimate stopping may boil down to tire adhesion limits, there are a lot of other factors that go into braking performance, the friction material being only one.

The whole point to any of my answers to this thread was not to argue all the various aspects of brakes, but to address the shop owner's assertion that the best pads are OEM and only OEM pads should be used, and he states a couple of in-decipherable reasons for this opinion. My answer to that specific point is if he truly believes that as fact, he needs to do some homework as anybody that has done any high performance brake work will tell him that more often than not OEM pads are easily improved on.

Some Pete Guy

Price point, marketing, the V8s are more likely to be used to tow heavier loads, etc.

As long as the stock brake system is capable of locking the tires "upgradiing" the pads will not shorten the ultimate stopping distance, although they could improve fade resistance.

Based upon my experience with MLs, the OEM pads work just fine, even when they are pushed really hard.

The fact is that much of the "high performance brake work" is done by people for all of the wrong reasons, like "i want to shorten my stopping distances, etc. so I understand why he's skeptical about after market pads and the claims associated with them.

As far as OEM pads being "easily improved on" that really depends upon how you are quantifying the improvement. How can you judge them to be more fade resistant if it's very difficult, short of tracking an ML, to get the brakes to fade?

Cosmetic/aesthetic benefits of lower dust are easily seen but the claims about superior stopping are much more nebulous IMO.

I agree that to to dismiss "after market" brake pads out of hand is silly since most OEM stuff is made by the same manufacturers that make "after market" brake products (Brembo, Pagid, etc.).

SteveB

Since the 320, 430, and 500 all have the same rated towing capacity, that's not the reason. Also, they all have roughly the same curb weight, so that's not the reason. PRICE POINT!! That's the ONLY reason. Those fixed calipers & bigger rotors cost more.


There's a whole lot of data that would disagree with that assertion. Locking the tires has absolutely nothing to do with braking. In fact, it's the worst thing that you can do when braking. Once the tires are locked, the brakes aren't doing anything. That's the whole reason for ABS. Threshold braking is the most effective way to stop a car in the shortest distance. Friction material compounds absolutely can affect the ultimate stopping distance.

As you say, the OEM pads work fine. However, there are pads out there that can and will work better. The Rotex pads I use emit less than 10% of the dust the stock pads do, they last about twice as long, and they have much better fade resistance. A worthwhile upgrade IMO.

startcraft33

Just curious where and how much to get Rotex pads for ML320. If possible, does it ship to Canada? Thanks.

SteveB

Rotex pads are made in Canada, so I would think it would be easy to find a local shop that carries them.

Some Pete Guy

Ok, do you have any links?

I'll trade you this one for any that you have that indicate that brake pads reduce the absolute stopping distance:

Brake info

Uhhhhh...being able to lock the brakes is a certain test of the efficacy of the braking system. You're the guy that is apparently claiming that adding "better" pads will shorten stopping distances.

If the stock pads are sufficient to overcome the grip of the tires (lock the brakes), how are "better" pads going to do better than that?

I'm quite familiar with threshold braking and ABS.

How can brake pads affect ultimate stopping distances (not fade)?

Dust is aesthetic obviously.

How do you quantify better fade resistance? Again, I've never been able to fade the stock brakes in "spirited" street driving despite getting them very hot (they smoke due to their compund). How did you get your brakes to fade?

p.s. Another reason for bigger brakes on the V8 MLs could very wll be because they are able to accelerate more quickly corner to corner and need to deal with more heat, although I'm sure it's only a small percentage of folks that actually flog their MLs through the twisties.

SteveB

I would suggest that the brakes on the ML500 are what should ideally be on a vehicle of that size & weight. The brakes on the ML320 are simply the result of cost savings measures. HP shouldn't have anything to do with it. The brakes are supposed to convert forward inertia to heat. They don't care about hp, only weight. But, maybe the manufacturers assume with less power, you're less apt to be driving in manner that would require good brakes. So, they downgrade them to save a few dollars on the cheaper models.

Would you expect your turbo to have the same brakes as a Boxster? Why does Porsche put better brakes on the S than the 2.7? They both weigh the same. Cost savings, pure & simple.

anyway, from the Performance Friction folks.....


WHAT IS CARBON METALLIC®? Carbon Metallic® is Performance Friction Corporation's brand name for its brake pads. They are completely different from organic or semi-metallic pads. They offer superior braking pedal feel and longer life without fade at high temperatures. As the name implies, they are of Carbon Metallic® composition as opposed to being organically based as other main stream brands of pads. Carbon Metallic® contains no as-bestos, no kevlar and no lead. Organic and semi-metallic pads use clay as a filler to cut costs. This sacrifices performance. CAN I TELL A DIFFERENCE WHEN USING CARBON METALLIC®? Performance Friction Carbon Metallic® pads are extremely strong which offers superior brake pedal feel. Less strong organic/organic based or semimetallic pads actually can compress especially when hot Carbon Metallic® pads continue to grip even when hot, offering consistent braking and pedal feel. There is no good, better or best grade. There is only one Carbon Metallic®. This strength also makes Carbon Metallic® more compatible with ABS.


If you think that's just marketing, stick with the stock pads. I've installed enough different brake pads on my cars over the years to know there's a very definite difference. I always upgrade to a better pad, if available. I know my requirement is the best pad I can find, and not saving a few dollars like the manufacturer has to do.

Is it overkill for the way I drive? Maybe. But, for that ONE time where it does make a difference................... you decide.

Some Pete Guy

Hmmm...so why does the Turbo get bigger brakes than the NA 996?


I don't see anything in that marketing blurb that supports your contention that pad material shortens ultimate stopping distance.

Did you happen to read the linked article which specifically refutes your claim?

That's the point that you seem to be missing. You're claiming that a pad change will help you in a single instance/ultimate stopping distance situation.

The "experts" disagree with you (see link again) and you haven't provided any of the "whole lot of data" that supposedly supports your claim.

As far as knowing that there is a definite difference, the placebo effect/expectations can certainly account of a lot.

FWIW, I have "upgraded" pads on my other car and don't notice any difference in stopping distances. If anything, stopping distances are allegedly longer on the street but I can't say that I've ever noticed.

SteveB

Umm, I think I already answered that, you just made my point
$115,000 car vs $75,000 car

Did you read it?

"Do brakes dissipate energy at a constant rate? My guess as a physicist is 'probably not.' The efficiency of the braking process, dissipation, will depend on details of the friction interaction between the brake pads and disks. That interaction is likely to vary with temperature. Most brake pads are formulated to grip harder when hot, but only up to a point. Brake fade occurs when the pads and rotors are overheated. "

Hmmmm..... see the part about depending on the details of the friction interaction between the brake pads and disks? Fade occurs when the pads and rotors are overheated.

So, it sounds as though he acknowledges that all pads are not equal.


additionally......

"We now arrive at the second way of looking at this problem. Let us assume that we have good brakes, so that the braking process is limited not by the interaction between the pads and disks but by the interaction between the tires and the ground. . . . "


Now that you've optimized the brakes by making them bigger, or better pads, or stainless steel lines, or any other modifications necessary to get to the point where the only limiting factor is the tires. THEN & ONLY THEN is grip on the road going to determine ultimate stopping distance.

So, you see, you've not only answered your own questions, you've helped illustrate my point as well ! Thanks for the article, it helped!

SteveB

oops, forgot this part of your article.....



So folks, we have discovered the true reason you may need bigger brakes. If your car is driven really hard, such as in track events, and you encounter brake fade, you need to get better heat dissipation for your system so your fluid doesn't overheat or your pads don't go off. To correct this you can use a better brake fluid, get effective brake coolers, get better pads, or (finally) get BIGGER BRAKES.



Hmmm, ......"get better pads"......


Yes, it seems as though that is part of upgrading brakes !

Some Pete Guy

rotflmao!

So the only reason that the Turbo has bigger brakes is because it costs more?

It doesn't have anything to do with the performance differential between the cars?

You should hit the library and check out Powerplay. There's a whole chapter devoted to the development of the brakes, with the real answers as to why it has bigger brakes.

Yes I did.

Obviously (although fade can also occur when the pads and rotors are short of overheating but the brake fluid is boiling off). How do you get from some pads are more resitant to fade, to adding pads will reduce your ultimate stopping distance (defined as a single stop event, like R&T's 60-0 tests)?

From the beginning I've acknowledged that some pads are better under high heat circumstances. Heck, that's why I run Pagid Oranges.

Obviously. Again, how to you make the leap to shorter stopping distances by simply swapping out pads?

Which is the situation with a stock ML with stock pads...

Uh, it's obvious that you didn't understand the context of what you read. The point that was made is that the brakes are already optimized on modern cars.

It seems that you're ignoring this bit right here:

"You see, how fast you stop is determined by your tires, not your calipers, at least in any Porsche. For one minute forget about threshold braking and think about braking with all four wheels locked (and with no directional control). Most any car can do this (that is, lock-up all four wheels). Once this happens you have shown that you brakes have a higher grabbing power than your tires. Your wheels have stopped moving and that is all your brakes can do. Now your stopping distance is a function of the friction between your tire and the road surface"

Again, why do you think that adding your aftermarket pads to your ML will shorten your ultimate stopping distance?

Additionally, you've never explained how you quantified the better fade resisitance vs. stock pads. HOw were you able to induce brake fade?

SteveB

No, the main reason the 996 brakes aren't as big as the turbo's is that it costs less.

Your question:

Let's revisit the article:

Ok. So, you acknowledge that some pads are more resistant to fade than others. The problem with the rest of your hypothesis is that you seem to think that fade can never occur on the first single stop event, like R&T's 60-0 test. Do you really think that all brakes are capable of maximum power/shortest stopping distance, without ANY fade, on a 60-0 stop? As the article states, it depends on the relationship between the friction material on the pads and the rotors, which varies with temp, AND pad formulation.
He states that there must be an interdependant relationship between all components, but one must also deduce that a certain independant relationship exists as well. For example, if you heat the system to where the fluid starts to boil, raising the boiling point of the fluid by itself would be an improvement. Hence, if the pad fades at a given temp, changing the pad to one that wouldn't fade untill an even higher temp is reached (but still below the fluid boiling point, of course, so as not to introduce another factor yet) would have to bring a corresponding improvement in stopping power.

Any system is only as good as the weakest link. To the extent that the pad is what 'fails' first, then improving that single component to the point where the next weak link exists has to bring about a corresponding improvement in the system.

Therein lies the disagreement. I'd bet that MANY cars could benefit-- in measured single 60-0 stops-- with simply a pad upgrade. They start to fade towards the end of that FIRST hard 60-0 stop! That's how bad some factory pads are, especially coupled with what could be argued as undersized brakes.

If the brakes start to fade on even the first stop, then changing to a pad that doesn't fade as soon would, by definition, have to shorten the ultimate stopping distance.

Some Pete Guy

Again, that's obvious, and doesn't apply to single stop events. Why do you think that pad manufacturers recommend such a rigorous bedding-in proccess for new pads? Because it takes a few hard stops to get the rotor and pad up to a sufficient temp to transfer pad material.

So again, how have you caused to pads on your ML to fade, let alone fade during a single sstop event?

Furthermore, you claim that there is a whole bunch of info available that supports your claim about pad material affecting a single stop event, where is all of this info?

In the case of the ML, like most, if not all, modern vehicles, the "weakest link" is the tires since the stock brake system is more than capable of overcoming the adhesion limits of the tires.

You're right. There is a huge disagreement right there.

If manufacturers were putting brake systems out that exhibited fade in a simple single 60-0 stop they would have their hands full fending off the resultant lawsuits.

I wonder how all of those skid marks get on the roads given your comments?

That's a HUGE "if," and I would be more likely to lend it crednece if you were able to offer some of that info that supports your claim, and contradicts my personal experience, the experience of numerous instructors, and the experience of "the experts" who know more about this stuff than I do.

Again, my experience, with the ML, has been that it's very difficult to induce fade using stock pads. This includes a very "spirited" 2,000' vertical descent, in 100 degree heat, down a very twisty bit of luscious pavement in the mountains outside Tuscon.

Tires were squeeling, ABS was working and the brakes were smoking by the end but there was no noticable fade.

Using stock pads. Go figure.

SteveB

Where's your info to support your claim? The one article you quote actually supports my claim better than it supports yours.

Also, in your Tucson ride, I assume this is in your ML55? Do you think the results would have been the same in a ML320?

Now you're saying ML brakes NEVER fade? Thought you acknowledged that they did fade, but not in a SINGLE STOP event, like R&T 60-0 stops.

You're talking in circles, contradicting earlier assertions. Keep your stock pads, I'll throw mine in the trash & we'll both be happy.

Hopefully, we'll both get stopped in time before hitting anything, which is all that matters.

Some Pete Guy

Uh, Steve, that's not true. Read the article again. The entire article.

Read this part a few times:

"You see, how fast you stop is determined by your tires, not your calipers, at least in any Porsche. For one minute forget about threshold braking and think about braking with all four wheels locked (and with no directional control). Most any car can do this (that is, lock-up all four wheels). Once this happens you have shown that you brakes have a higher grabbing power than your tires. Your wheels have stopped moving and that is all your brakes can do. Now your stopping distance is a function of the friction between your tire and the road surface"

You're the fellow that claimed there is a "whole bunch" of info that supports your claim. To date you've only provided one marketing blurb that doesn't even support your claim, let alone contradict the link that I provided, nor contradict my personal experience.

Where's the beef?

No, it was in the ML 430. The same brake system that you have on your Ml 500, where you claim the replecement pads are an improvement, yet you seem to have no experience exceeding the limits of the stoick pads.

I don't know if the results woould have been diffeerent in the 320, I've never driven one hard.


Nope. I never made that claim. You're trying to put words into my virtual mouth.

As noted before (read the thread again to refresh your memory), I'm sure that I could get the pads to fade on the track. My experience, during very "spirited" street driving in high temps was that they didn't fade.

Which begs the question about your "upgraded" pads:

How were you able to induce fade and quantify the difference between the OEM pads and the aftermarket ones?

Also, you've never answered this question:

How can you judge them to be more fade resistant if it's very difficult, short of tracking an ML, to get the brakes to fade?

TSk, tsk. Very poor form Steve.

I haven't contradicted anything. I merely shared an experience.

Which part of "it's very difficult, short of tracking an ML, to get the brakes to fade" are you struggling with?

SteveB

Well, as evidence goes--

I don't recall anything in your quoted article that is based on any sort of test data. No times, numbers, double blind tests, variables cited, nothing. At least, the Performance Friction 'marketing piece' I quoted compares actual friction compounds they manufacture and identifies specific properties associated with theirs vs OEM pads.

Your article is simply a theoritical piece based on hypotheticals, supposition and speculation. Not to detract from the possible accuracy of the ideas set forth, he makes very good points which are most likely correct. However, it's still broad and theoretical in nature, with no specific references to hard data. If you break it down carefully to component parts, you can see that he has introduced the idea of the complexity of several different forces all acting concurrently to create a system called "brakes". While identifying the specific parts and relationships of those parts, he had to let several assumptions stand as givens for the sake of brevity in an article designed to address the inherent misconception that "bigger is always better" as and end unto itself. In this context, it's assumed that other variables are present, but assumptions are let stand for the sake of the point being made. An article that focuses specifically on friction compounds and their sole contribution to, or detraction from, braking performance absent other variables would be more applicable to this discussion.