Stuka Bomber

Got to work on the factory brakes on my 4matic c280 tonight. Stripped the star head rotor bolts, caliber hardware is all seized together, pads rusted to the caliber carrier. It's all locked up.

Is this normal? I've never had issues this bad on a car of mine.

Thanks guys!

ncmudbug

Two things to get out first: I don't know how experienced you are and it's been a while since I've had to change my pads on either of my cars.

IIRC, the bolts that hold the caliper on are hex bolts. You cannot see them from outside, they bolt the caliper to the upright from the inside of the wheel assembly. You would only need to loosen them if you need to replace the rotor or the caliper. If you were trying to loosen the 'star' bolts that you can see from the outside of the car, you should be glad you didn't succeed. It's a large pain to put the caliper back together again.

In fact, you don't need to loosen any bolts to change the pads. You have to drive out the pins that hold the pads and the anti-rattle springs. There will probably be a slight ridge around the circumference of the rotor. Carefully pry on pad to compress the piston and then do the other. They should come out.

Do the opposite to put it all back together. Remember to pump the brakes before you go anywhere in case you lose your pedal. It should pump up easily.

Now, all that was assuming that you're not sure you know what you're doing. If you do know what you're doing, you've got something I've never seen on a running car. If things are as frozen up as you say - especially on the front - the car would not stop very well.

Does that help?

Stuka Bomber

^yes sir. That helps. I'm actually pretty familiar with the process. Just confused as to how everything can be so locked together. I was referring to the Torx bolt holding the rotor to the hub. That is stripped out already.

I've never experienced this level of corrosion on suspension components in any of my cars that are much older than the mercedes. It's new to me.

Maybe everything just needs a soak in pb blaster.

TexFinn

Based on the car you have, I'm assuming you reside in Canada?

If that is the case and you happen to live in one of the areas where there is salt used on roads during the winter, having things a bit corroded after being there undisturbed for six years doesn't surprise me too much.

A healthy dose of PB Blaster, WD40 etc. should cure the problem.

phister

PB Blaster all the bolts like TexFinn says and let it soak. now if the torx bolt holding the rotor is stripped you can get a dremel and cut a groove in the bolt and use a flat head to remove it. But it shouldnt be seized that bad since the bolt isnt that long. but were you planning on replacing the rotors and pads? or just the pads?

ncmudbug

I've had the internal torx bolt that holds the rotor on the hub freeze. I had to get a dremel tool and grind it out. I stopped several times and tried different things but I eventually had to grind it out.

Phister is right - start by soaking it with Kroil or LiquidWrench or similar, but if that doesn't work, get out the dremel tool. Good luck!

Boom vang

drill out the head of the torx set screw then pop the rotor off and use a pair of vise grips to turn out the screw after a blast of PB. If it still does not come out cut the screw flush with the hub and drill out the screw with a bit slightly smaller than the hole ie size it with the available hole on the other size so that it does not cut the treads. You may need to re-tap but in most instances by the time you are part way through it usually starts to unthread itself and comes out the back stuck with the drill bit

In most instances you will be able to get it out with the vise grips. Almost every Japanese car I have had to do this as they are either slots of Phillips that cam out. Usually the torx will not strip and the quality of the screw that MB supplies is actually really good. Perhaps you used the wrong torx size in the first place.

You may need a BFH to separate the rotors from the hubs as over time they tend to bond to each other

Boom vang

WRONG: unless you are talking about the rears. The front is a sliding caliper on the C280 and has to remove the caliper in order to get the pads out of the bridge. Only the 230 sport 350 sport and C32/55 had fixed calipers on the front, all the others had a Lucas single piston slider

samaritrey

Be careful with the rotor if it is stuck on and you end up having to hit it or doing the bolt trick. I tried the BFH on one of mine and it would not move so I did the bolt trick and when it finally did pop it sounded like a gunshot and I have lost some hearing in my left ear because of it.

Boom vang

bolt trick is a great one and had the option on every Japanese car I've owned but none of the MB rotors that I bought for my car ever had that extra treaded hole I usually use a dead blow hammer and work around the rotor

Boom vang

oh and BTW if you are replacing the rears rotors you have to back off the shoes in the internal drum in order to get the rotor/drum brake off. Don't use a BFH in this area as you will ruin the shoes and mechanism. If it is bonded to the hub use a hammer to strike towards the hub in order to break the bond

ncmudbug

I have a 2005 & 2006 C230. Both have fixed calipers in the front. I consider them more desirable than floating calipers (maybe my prejudice) so I expected that a 2008 C280 would have them also. However, for cost savings they may have floating calipers in which you would have to undo the bolts that the caliper floats on to take the "floating" part off and replace the pads. If so, I stand corrected.

Boom vang

No prejudice, fixed calipers are better, they also look much better. Unfortunately here in Canada very few C have front fixed unless you optioned for the much more expensive sport package where as in the US they came that way right off the bat. At the time the CDN $ was low and they were cutting as much cost off the car to bring it in at a decent price. We (I) got robbed and would rather have the 4-pots that US versions of my year that came with. Unfortunately now would be an expensive mod as I would have to change all the brakes as well as get another 4 wheels and snow tires as I used the OEM 16" as my winter wells and have the 17" staggered as my summer shoes

Boom vang

C280 was sold both north and south of the border from 2006 to 2007, also was a basis of the engine for the c300 in 2008.

Also the fact that the title was 39,000mi would indicate it was a US car

TexFinn

Yeah... I thought I was in the W204 section...

johnand

LOL, I feel your pain. Just finally started the project of replacing my pads and rotors on my 2007 with 111K on all the factory parts. The Torx bolts came out fairly easy, but I had to beat the living hell out of the rotors to get them off. That was even with a generous helping of PB Blaster. The hubs have big holes in them, that allow moisture in between the hub and rotor. Word of advice, once you get them off, use some Scotch Brite and clean the hub well, and coat the entire hub surface with Anti-seize. That should make it a breeze next time.

ncmudbug

That's a good idea, John. I wish I had thought of that when I did mine!

Something else that helps is a dead-blow hammer but even with that, it can be bear to get off the hub. As someone once said, "perseverance furthers".

And then there's the advice from Churchill and Coach Valvano: Don't give up! Don't ever give up!