Rick

At 42k miles, the dash lit up with a happy little warning message about the brakes. I inspected them and there was some pad left, but it was obviously time. I did this work back in February, and finally got a chance to write it all up...hope I didn't forget anything, but I think it's all here.
(Moderators; if this should be moved to tech forum, please do so, but it's about the coupe and I don't want to cross post)

REPLACING BRAKE PADS ON 2002 COUPES
I got the complete Porterfield Kit from Jerry at ForMyMercedes.com
You'll need 1 sensor (from your dealer) for the front right caliper on C-Coupes.
Tools required:
17mm socket wrench, breaker bar, floor jack (stands help) or lift, flat blade screwdriver, vice grips, a small piece of wood (or a wedge like I have), 1/8' punch brake seating "grease" and a hammer.

Open the hood and remove the cap from the brake fluid reservoir, place a rag over the opening and around the base to mop up minor (but inevitable) spills.
Use the center jack points to lift the car then support it with jack stands at the side jack points (do one "axle" at a time). I did the fronts first.

Take the wheel off to expose the rotors and calipers.
Inspect the rotors. If you think they might be warped, replace them.
The sensor is on the inside pad of the front right, and unplugs easily.
Remove two 17mm bolts on the back of the calipers that hold it in place.
(Don't take out the 19mm bolt unless you are replacing rotors too.)

Compress the inside pad as much as possible, this is where the piston is located (I used a plastic wedge).
Carefully pull the caliper up and over the rotor.
Support the caliper on a sturdy box or bucket while it is resting.
Slide the old pads toward the center and pull them out one at a time.
(the rears have a tension spring and pin - a 1/8" punch will help)

I use a 3" long x 1" square plastic wedge from an old brake kit (I think it's from when I had my Celica or Scirrocco) to compress the pistons on the calipers. You can also try vice grips, or a piece of wood and a C clamp. With the old pad removed, slowly push the pistons completely into the caliper housing. Be careful of the rubber seals around the calipers and the hydraulic line.

Apply a very thin coat of brake seating "grease" to the back and to the side tabs of each pad. This will help them hold their place (All car parts places carry it...various brands). Just be sure to keep it off the caliper piston, pad and rotor surfaces. This stuff seats the pads when the calipers close and reduces vibration and shifting.

The groove in the spring clip where the side tabs for each pad slide in needs to be clean and free from debris. Use an old toothbrush or compressed air to clean out any brake dust, rust flakes, etc. Apply a very VERY small amount of grease on the side tabs of the new pads to help slide them in. Some might say not to do this, but it helps because the clips are under tension.

Position the new sensor in the hole of the inside pad, then position the caliper so you can plug it into the connector. Put the pads in the caliper. Carefully slide the caliper over the rotor and bolt the assembly back in place.

The Porterfield kit includes and aluminum spray that sort of resurfaces your rotors if there are any minor grooves or pitting. If you need it, spray it on as soon as you take the caliper off. I only had to use it on the left rear, but I thought I'd mention it because it really does give you a smooth surface. It dries in about 20 minutes. Lightly sand it with the included sand paper, using finer sheets as you progress. At that point you can put the caliper back on the treated rotor.

Install the wheel.
Repeat on the other side (minus the sensor).
Lower the car and do the rear axle....

The only trick here is that the rear calipers have a spring clip and pin that has to be removed. Compress the spring clip, and tap the end of the pin with a hammer. Once the pin is inside the caliper housing, you'll need a punch to drive it through. It's collared, so once that's passed the spring clip, it slides right out. To replace it, slide the pin through the back of the caliper and the positioning hole on the back pad, compress the spring clip and slide into the front of the unit. Tap in place with a punch and hammer.

When you're done and that car is on all fours again, cap the brake fluid reservoir and get in, pump the brakes a few times. Uncap, then recap the reservoir and do it again. Be careful for the first few miles, it'll take a while for the new pads to sink in. The instructions Jerry sent said to drive slowly and wait for the brakes to heat up before trying any fast stops. This will help seat the brakes and acclimate them to the rotors.

A note about the sensor;
The MFD Brake Wear message is a result of a pad thats worn enough that the sensor makes contact with the rotor. The sensor is just two wires imbedded in soft plastic. When the plastic wears down to expose the wires, they contact the rotor. This makes a complete circuit, and hence the message on the display. If you see the message...the sensor is shot, so it's best to replace it ($8.00 peace of mind)
My E320 has one sensor at each caliper...I guess this is one reason my C230 was MUCH less expensive.

The whole job took about 2 hours...I followed someone else's "instructions" for the first wheel and they had it all wrong. So after the tool scramble, each wheel took about 10-15 minutes.

mike82y

I have a question regarding brakes

I havent driven my C240 for about a week now and today when i was driving the car i feel very strong vibration on the brake padel when i apply the brake.

First i thought it could be some dirt on the brake disks, but after some driving the vibration is still there... The car only has 22000Km on it.. i really dont really know what the problem is.

ps. the car is stock, no mods.

please help!

Mike

Rick

Mike,
You would probably get more replies if you posted your questions seperately, but it sounds like you're problem might be a slight oxidization of brake rotors (aka rust). Run the car for a bit, stretch it's legs, let the brakes heat up and if the problem still exists, visit your dealer for warranty service.
This post is about Do-It-Yourself Brake Pads....the dealer wanted $1280 for what I did in 2 hours (and I used better pads).

amdeutsch

Great write-up. Thanx Rick. Lets sticky this one for a while to give peeps a chance to copy and download.

MB-BOB

For the C320, there is a sensor for each front wheel (that's two, total), and the bolt that holds the caliper assembly to the rotor is 18MM bolt (not usually supplied with a metric set... I had to look through three sets of tools to find the right size.) I left the sliding caliper in the caliper assembly, and loosened these 18MM bolts to remove the entire caliper as a unit. There was some blue lock-tite on these bolts, so I used a drop or two on each when reinstalling.

I did only the front wheels, at 35,000 miles. Pagid pads. $82 for front pads, four packets of anti-squeal (used all four) and a pack of 4 sensors, from http://www.autopartswarehouse.com

vadim

Thanks, Rick! Nice write-up!

Just wanted to add a couple of things. First: a small bungee cord with metal hooks (usually sold in auto stores in kits of assorted sizes) can be used to hang a loose caliper on the spring to avoid damaging the brake line.

Second: do not forget to properly bed in the newly installed pads and/or rotors. You may run into some nasty problems if you don't.

Here is a good article explaining bedding-in procedure and providing some background on the subject:
http://www.zeckhausen.com/bedding_in_brakes.htm

Rick

ok, Vadim...valid point...
The tabs on the sides and the thin layer of grease help that...it's almost goof proof with pretty tight tolerances. I should mention that once you seat the pads, there's a little give...that is, you can shift the pad at slight angles....til you feel it fit just right.

The other thing I should add is that the Porterfield R4S's are far better than stock. When hot, they stop shorter and even have a better, more solid feedback. All this with a lot less brake dust makes this a HUGE improvement....worth every penny and busted knuckle.

20FHK02

Question:

"Apply a very thin coat of brake seating "grease" to the back and to the side tabs of each pad. This will help them hold their place (All car parts places carry it...various brands). Just be sure to keep it off the caliper piston..."

By that did you mean apply the grease to the pad's back EXCEPT a circle un-greased where the caliper piston seats on? If you grease the whole back, the piston end will touch the grease after installation, so I don't quite understand what "keep it off the caliper piston" means... TIA

Rick

Yeah...I meant to put in "back edges and side tabs" when I caught that, but it was more than 24 hours and I couldn't edit it.

I figured most people would catch it, but not critically question it since the following warning made it almost self-evident.

Have a pint at your local pub and e-mail me the bill...I'm buyin'!

20FHK02

Beer? I'm drinking it now - it's a bottle though

I just want to make sure the procedures as my Porterfields are very squeaky... I bought the anti squeal paste and wonder where to apply it... The package says put it on the back but people here heavily warns about anything touching the piston...

c230kracer

my car is around 14 k miles and the brakes are starting to SQUUEEK a lot...i dont know what really made this occur but its annoying...is it something that i have to change? like new pads or rotors or is it something i can easily solve...even heating up the car and waiting for it to get a little heat doesn't work still...squeeks...thanx

TNblkc230wz

The 320 coupe uses one sensor in 03, but needs the 18mm socket. You can get it at Sears.

MB-BOB

I put the grease on the back of both pads. The outer pad rests against two arms of the caliper itself, so I was liberal with the grease where these parts touched. The back of the inner pad rests against the piston, so I tried to form the grease into a circle matching the diameter of the piston, but not the area of the boot seal surrounding it. Time will tell if I did this right, but I was totally fed up with the persistent squealing, and I wanted to eliminate all sources of friction, AND the OEM Lucas pads I removed had traces of anti-squeal grease on both pads, including the inner piston and its pad. So, I thought this was OK to use grease on the piston-side pad.

MB-BOB

I wish I took pictures... My comment here is that the business end of the sensor is a circular rod about 1" (25mm) long and about 1/8" (3mm) in diameter. The sensor press fits into a hole drilled into the pad material that runs parallel to the surface of the pad. The hole is positioned closer to the back plate than to the exposed surface of the pad, but there is .020"-.030" of pad material separating the sensor from the metal back plate (to isolate the back plate electrically from the sensor).

Adding this relief thickness to the overall thickness of the sensor, means that the edge of the sensor that first comes into contact with the rotor when worn is just slightly less than 1/4" total thickness. Stated another way, then the MFD warning light first comes on, your pads are not in imminent danger of wearing through to the backing plate. Far from it. Instead, the light means you have slightly less than 1/4" of pad remaining. Since the new pad is only 1/2" thick or so, this means the pad is only about 60% worn out when the light comes on.

If you can stomach the constant MFD reminders, my guess is you can easily drive the car another 3,000 miles before the pads truly need to be replaced. Don't take this as gospel, as we all drive our cars differently. This is just my opinion. At least I now know that in the future, I have plenty of time (within reason) to change the pads after the warning message first appears.

20FHK02

I greased the entire back of both pads. Still a bit squeal when I stop hard, but MUCH better than before!

c230kracer

the squeeking is comming from the pads right? so simply changing the pads to new ones would make the squeek go away?

EM9TEH

What is this? Why are you doing it?
I changed the brake pads many times. Never opened the hood or anything.

superduper

Thanks for post, very informative.

I KOMPRZ

Just got the warning of Brake Wear...at 25k miles, isnt it a little too early? Or coz I am in the LA area with bad traffic all the time?? Also when I buy replacement pads, there are two types, MB-BOB I know you said yours $89 so thats the regular pads...but there is also a "Sport Package or AMG Package". Which one should I get? I believe all C230k are sport package right?

Rick

Run it by your dealer's service center. Ask them (NICELY) if they can cover it under warranty. If not, call Jerry and DIY them. The sensor was like $8....the brake kit was about $260 with shipping (if I recall correctly). The whole job takes about an hour if you have the tools and a little experience. The dealer will charge you $1280 for a brake job.

I KOMPRZ

When i purchase this car, first thing they told me was "Brakes are not covered under warranty". SO I doubt they get covered unless someone can hook me up. As for the brake kit, its $260?? I found some EBC pads for the front $82.85 free ship....and I have enough experience to change them out myself...so I can save that $300. Just wondering why they need to be replaced so soon at 25k miles.

Rick

The kit I used are kevlar/ceramic pads....very little dust, better stopping power with less fade than stock pads. It's a complete kit that includes front and rear pads, rotor refinishing spray, pad "grease", sand paper, instructions and shipping. You can go cheaper, but you own a Benz and should therefor know that you get what you pay for.

As for the 25k wear....maybe it's your driving situtation. Stop and go traffic can kill brakes. Or perhaps it's your driving style...but I won't chastise you here for that.

mdp c230k

I got 18k out of my fronts. It's all the type of drioving you do, mine is 95% city stop-and-go. I used EBC pads and I like the, less dust better stopping distance and feel.

Saprissa

i'm hitting 24,000 miles and time for Service B.

I changed to the C32 AMG brakes somewhere around 6,000-7,000 miles,
and now they're starting to squeal, but not that much.

I'll probably have to change out the pads. Time to bring back from the dead and dig-up that old post with all the MB pads vs aftermarket pads thread that's here somewhere.....

I know there are new MB pads for C32 & Sport models that are less-dusty,
different part # than the old ones,
gotta find that too !!

should of noted it down, when I first read it, just like a bunch of other stuff on this forum

Carlos

Saprissa@aol.com

I KOMPRZ

Ok all the experts, my pads finally arrived today. So off I go, did everything as usual...off reservor cap/wheels/caliper....then I go "***** wheres my C-clamp!!!" ....well yeah I couldnt find it...so I had no tool to compress the piston, I tried using a long screw driver...a rod...a wrench...I tried everything and it didnt wanna compress at all...did I miss something? I shouldnt even touch the bleeding bolt right? Or I just simply need the C-clamp??....Please help.