Just swapped pads on W123 and brakes feel weird, how long till they break in?
 

I assume it will take a little while for them to wear to the existing grooves on the rotor.
Anyone know how long it will take?

how do they feel weird? Maybe you hit the bleeder screw by accident?

If you actually have noticeable grooves on the rotor, you should turn them before fitting new pads.

Also, did you knock off any glaze with some emery cloth before fitting the new pads?

If your rotors are glazed and grooved, it could be a few thousand miles before they start feeling "normal" again. I would at least knock off the glaze, which will help.

Good luck.

Well I broke the bolt off one caliper and gave up called a mechanic and it ended up costing $200 in labor and 90 for a new caliper for other side. He came to the house, so it wasn't so bad, but I figured to throw in the towel before I really screwed everything up.
I have to ask him if he nocked the glaze off.
He said he would.

Replacing a caliper is pretty crucial to the way that the brakes are going to feel and definitely affects a whole lot more than a simple pad replacement. However it doesn't answer my question - how do they feel different? Firmer? Softer? Worse/longer stopping? Spongy?

I just looked at the rotor through the rims and they are glazed up.
Do ya'll think I can get away with hitting up the exposed one side with a rough pad on my orbital? the rear side is shielded and I don't want to break anyting else?
I guess that would make it a little better at the least.
I just can't put any more money into this. Gotta fix it and sell it, but with a clear conscience

Pedal is firm seems good, they take as long as before to stop. I feel like I could make it stop if I slammed it, but I don't want to muck up the pads by abusing them before broke in.
I'm sure the guy bled the brakes, but he clearly didn't nock the glaze off.
I used good pads.

Can't speak for whether he got air out or not but the way to seat the new pads to the rotors is to get up to around 40 and then get on the brakes down to around 10 mph, speed up and do it again about two or three times. Then get up to 60 and bring it down to 10 braking harder each time. Do this about 10 - 15 times. This should seat the pads in.

Of course that's assuming he has clean rotors, if they are glazed that may not help much, if at all.

OP, you don't need too much. Just raise and safely support the car one wheel at a time (for whichever ones you replaced). You can use a sanding block on the front side (a power sander is likely to make things worse as you might end up with an uneven surface)...all you want to do is remove the "sheen" from the rotor and leave it looking scuffed-up. Work in a small circular motion. The inside of the rotor is tougher because of the shield, but the gap should be big enough you could wrap the emery cloth around a phillips screwdriver shaft and use that to reach in and rough things up. Work on one area, then rotate the rotor a little. It will take you lots longer that way, but it will work. It will be easier if you remove the pads, since you can reach in to the back with your hand then, but I leave that to you to determine.

I can't judge the wear grooves on your rotor over the net, of course, but if they are significant then after knocking off the glaze, I'd probably then just drive normally (but easy on the brakes) rather than trying to bed them in through a normal procedure which is really aimed at new pads with new rotors.

As with anything else, judge for yourself what you most want to do. ;)

Good luck.

Chris, best to replace the rotors if grooves are apparent. MB advises against turning rotors. Purchase new rotors at your local MB dealer. They are relatively inexpensive. The brake system is too critical to be cutting corners and trying to save a few dollars.