e24kgold

Hey Guys, Anything special I need to know for changing the brake pads on my 05 C230 sport. Any unusual tools? I know not to touch the 12mm reverse torx bolts on the front of the caliper, any other insight?

Thanks!

phister

Don't rip the brake sensors. Bleed properly. Akebono pads are great ones to get. OEM braking with hardly if not any brake dust.

Moviela

You will need a special tool to properly reset the pistons in the caliper. It is not cheap, but you will ruin the caliper if the piston is canted and not pushed straight into the cylinder. Inspect your rotors for flatness and minimum thickness. Workshop tools do not have the precision required to resurface rotors to Mercedes specifications. There is not much "meat" on the rotors to start, so if the rotor has seen two sets of pads it is time to change them. Pairs only please.

If your brake fluid is more than two years old it is time for a flush. Copper absorption will corrode interior parts of your abs system if you don't. Mercedes brake fluid is hard to find outside the dealers parts counter. ATE type 200 is close, but not easy to find either. Don't listen to countermen that tell you "everybody uses this stuff."

Get a new wear sensor. Ibex makes them, and Pelican sells them cheap. Take a picture of the how the wire and connector is dressed so you can do it the same way.

Factory pads come with new bolts and a packet of expensive lubricant. Make sure you apply it, and do not reuse the old bolts. Make sure to use a brake cleaner to get the debris off the sliding ways where the pads touch. Use a wire brush to remove the ridge of rust on the center of the hub if re-using old rotors. Wheels are hub-centric and will wobble if that surface that mates with the wheel is not clean and smooth.

If your pedal is spongy, you might have air in the lines. Phoenix now has a reverse bleeder that can force the air back to the reservior to bubble out.

http://www.ebay.com/itm/Phoenix-Reve...item1e5b085ab2

Use a torque wrench on all fasteners, including the wheels.

e24kgold

I think a c- clamp will work fine for the pistons. The wear sensors haven't been tripped, no need to replace. Just flushed the brake fluid 3 months ago, don't plan on bleeding it.

phister

I just use my old pad and press it in with c clamp. Never had an issue with bad seating.

ncmudbug

What Phister said!
Moviela is right about the need to flush, but since you've already done that, you're good. I don't know which bolts he's talking about that come with the pads. I don't remember any bolts (other than the lug bolts) that even play a part. Perhaps he's talking about the pins that hold the pads in. If I had new ones, I would use them, but I've never felt the need to change them. He's also right about checking the rotor or wear. I checked mine and they were on the edge of the acceptable width. I used a dial caliper and two drill bits (to measure the thickness inside the ridge. My wife's calipers were worn MUCH more than mine and her car was a CPO. I don't think the stealer cared about the rotor thickness. I changed her rotors, too.
I also like Akebono pads. They come with two wear sensors. I replaced the one sensor with the new one and kept the old one that had not been triggered just in case I needed it (I don't think I ever will).

Moviela

Anyone that uses a c-clamp to reset a brake piston has a fool for a mechanic. A little harsh, but if a clamp were acceptable, it would be shown in the workshop manual. Canting a piston can result in a pinched seal, leading to a leak, or spoiling the concentricity of the cylinder leading to less effective braking, or chaffing the bore leading to the inner pad wearing faster and leaks. The piston can also become so stuck you cannot move it. If the pedal can move it, it might not move with enough pressure to make an effective stop. You will find the car pulling and the pads not wearing as fast on that side.

A dial caliper is not a replacement for a brake micrometer. Using one in this application is like a watch without a minute hand. You would know it is about two, but you could not see it was 2:42. A brake micrometer has a deep throat so one can read the friction surface near the center of the rotor.

You can reuse the pins that hold the pads in the caliper you removed with a drive pin punch. You should change the anti-rattle springs and the caliper retaining bolts. See the attached picture of factory pad kit contents.

ncmudbug

Interesting that MB gives you new caliper retaining bolts. I've never seen it even suggested to change those bolts as part of any brake pad replacement on any car. I've never heard of anybody doing that even when I was racing... Sometimes manufacturer recommendations are way on the safe side. Lotus said to replace all nyloc nuts with every use. That's a bit extreme in my opinion. Certainly if my pads came with new bolts I would replace the old ones.

As for the accuracy of a dial caliper used in conjunction with drill bits to test the thickness of the wear area of a brake rotor - I beg to differ. I would not claim to get accuracy to the nearest thousandth, but it should be good to a ten thousandth or two which for the purposes of determining if the rotor needs to be replaced is close enough. I don't own a brake micrometer and I don't need one often enough to go out and buy one. You are correct, it is the appropriate tool, but the diameter of a drill bit is very accurate and using one on either side of the rotor and measuring the entire thickness, then subtracting the thickness of both drill bits should get you very close - as I say, close enough to say whether it is time to replace it or not.

As for the tool to compress the caliper pistons - the proper tool is always better. You're warning of what can go wrong is valuable and an important reminder that if you don't use the proper tools, more care must be taken - and indeed more risk is taken. I guess I and all the people I know who have been using c-clamps and screw drivers (!) have been lucky - maybe luckier than we deserve. I've never known of anybody who had the problems you describe.

LILBENZ230

Me either. Four sets of pads and two sets of rotors in and I know my indy hasn't used any special Benz tool. No problems.

rcediel

Hi All,

I have a 2006 c230 which I am going to have to replace the pads within the next week. I found the following instructional video on youtube and found it very helpful. Any comments about the techniques shown?
I want to make sure I dont mess anything on my car.

rcediel

do you want to give me your feedback on the DIY video?

firstdown80

I'm about to get my rotors changed on the front of my 06 C230 Sport. But the instructional video indicates that the torque for the caliper bolts is 180Nm/135ft-lbs, but I've seen somewhere that for the W203 C230 it's 115Nm/84 ft-lbs.

Is there a difference between the 07 vs 06 model. I thought it should be the same since its W203.

ncmudbug

At the risk of blaspheming (again! see above), I'll give my $0.02.

I don't think it matters which torque value you use or even if you torque them. That is not to say that torquing them is a waste of time. It is the method that is dictated in the workshop manual and that is always best. However, torque values are quite often a guide to how tight to tighten a bold as much as a requirement. It would be really bad not to tighten brake caliper bolts properly and using a torque specification can insure they are not too loose.

Here's why I believe torquing caliper bolts isn't that important (as long as they are not too loose).

1. Caliper bolts are clamp the mounting ear of the caliper to the hub. Having one bolt tighter than another will not cause warping.
2. In many clamping situations, the stretch of the bolt is important to spread the load evenly or to assure that there is the proper pre-load on the clamped pieces. This situation does not exist on caliper bolts. The bolts are in sheer and the important thing is that they be tight so they do not allow movement.
3. It is almost impossible to over tighten them. Not only are they pretty large bolts but the rule of thumb is that if you do not break the bolt tightening it, it will hold. This was explained (mathematically) to me when studying for my mechanical engineering degree. I still didn't trust it till it was repeated by an engine builder I knew (US Mazda factory team that ran IMSA very successfully - google Team Highball and Dennis Shaw if you want to see how successful). Sometimes a guy who has his hands dirty carries more weight than a pointy headed engineering professor!
4. What is important is that the bolts are very tight so that they do not come loose and they firmly clamp the caliper to the hub mount. IIRC, the bolts come with a locking patch (similar to blue loctite). I think it is important to clean the bolt and internal threads (lacquer thinner is good) and apply more blue loctite. This in conjunction to a tightening the bolt very tightly will keep the caliper from moving and thus keep it properly aligned and it will keep it from coming loose.

There are lots of bolts that are really important to torque to the proper value. IMHO, these are not one of them. It is important to tighten them tight and if are worried that you don't know how tight is tight, then I wold advise you to use a torque wrench. I have never torqued bolts like these nor do I know of anybody who has (I have also never torqued spark plugs - but there is a torque spec for them too) and I've never had an issue.


Obviously, I don't know the correct torque value but 84 ft-lbs sounds tight to me.

firstdown80

@ ncmudbug

I think what you wrote makes sense. Anyway, I got my disc and brake pads done. Got all my parts from AutohausAZ, Bosch QuietCast Pads and Balo rotors.

Perfect!

ncmudbug

Glad it worked out for you!