95Sinned420

So, I had a brake pad sensor warning. I investigated, rear pads are fine, sensor clearly not near the rotor.

Investigated the front brakes, turns out one pad is worn down (the one with the sensor, front right). The outer pad one without the sensor seems to have more than 50% more thickness left. I can see the hole for that one and clearly there is quite a ways before that pad will wear down the the sensor hole.

It seems the inner pad is wearing down faster than outer pad. Stuck caliper piston? Front left pads are about 75% thickness left perhaps. Keep in mind I did a whole rotor and pad change in the fronts not too long ago, maybe 20k miles ago (75% freeway miles)?

Anyone experience this? Do I need to repair it or would a new pad change remedy it?
I've had an old w140 that did this exact same thing, the mechanic took a hell of a time pushing the caliper back in to put in new pads. Then all was well, never had the same issue again.

Just204

Not nessesarily the caliper,1 pad may be stuck and not sliding. Did you grease the pad mounts on the bracket both sides of the rotor? Check that first but if it moves smooth try compressing the piston some, if no go crack the bleader some and that should do it but keep an eye down the road for wear like that as that could mean a bad caliper.

95Sinned420

Yep, used dealer supplies brake paste on all of it.
Strange, it's not stick or having issues moving. I was able to easily pry back that pad a little with a screw driver with ease..

Just204

You could move both pads? If you could pry back the caliper then it's not seized.

95Sinned420

Yep, piston comes back and release the pads easily. What would cause one side to wear down then?

Just204

Did you grease the caliper sliding pins?

95Sinned420

The torx pins that are protected by a cap? Nope. This I didn't do. Didn't seem necessary since they didn't seem greased when I pulled them off.

Funkwagen

I had the same problem with one pad wearing faster than the other.

Definitely apply a thin layer of grease on them after cleaning them off. Mine were filthy with dirty grease when I serviced my brakes, so I actually sanded down the pins with a drill and some sandpaper, and then greased them.

I also noticed a huge amount of brake dust buildup where the metal sliding brackets for the pads are supposed to sit, it made the fitting tight for the pads and they wouldn't easily move even when greased. I sanded and filed down that part of the bracket until all the caked on dust was gone and reassembled.

No more uneven pad wear

FYI, this is for the "type 1" brake caliper that comes on non-sport package models. They look like this:




Sorry, only picture I have. The rotors and pads are smaller than the other style of caliper. You can usually tell because the rotors will have rows of 3 holes if they're drilled rotors, not 4 like the larger style

Just204

A lot of people miss that. Just because it's covered doesn't mean it shouldn't be lubed. I clean and lube All contact surfaces when doing brakes and never had any problems with uneven wear. Funkwagen, I have the rotors with 4 holes instead of 3. Is the difference because of a package option? Just curious.

pozi240

^THIS!
I have serviced brakes on most of my cars over the years, and most manufacturer's use the same setup on the front disc brake calipers. My old VW's would need servicing every spring like clock work. Taking out the pins and using a dremel and emery cloth, then some lube kept the pad wear even.

95Sinned420

Okay, I will try that. Will throw on new pads and thoroughly clean and lube the pins.

Funkwagen

C250 AMG/Sport models in Canada don't come with the larger brakes, while C300s do.

Code 950/952 is normally the code/package that comes with the upgraded brakes. I just found myself a set for cheap, can't wait to put em on.

Just204

Thanks, I had the feeling it was something like that. I always support the idea of better brakes ...

95Sinned420

So, I replaced the pads today. I guess it is both sides that show significant wear vs the outer pads. The passenger side was worse (the sensor side).

Anyway, I've attached the pics. The left (or bottom) set is the driver side, right (top) set is passenger side. As you can see, the inner pads are worn down a lot more than the outer.

I went ahead and lubed everything up, everywhere that has contact with each other. Even between the metal plates that the pads sit on.
I took out the pins/rods. It has a rubber cover that acts as a spring as well. The rods were both heavily lubed, I cleaned them and reapplied a liberal amount of lube. They weren't stuck or anything, everything moved fine before. But I went ahead and cleaned and re-lubed.
What I noticed was, the pins do not push themselves out, it is the rubber cover that acts like a spring that pushes it out. Without the rubber there, if I put the rods in all the way, they just stay there, so I am assuming these rubber covers act as a spring that holds pushes the caliper back.

Does anyone else have any ideas what causes the inner pads to wear faster?

SuperChargerE55

Is normal always like that and nothing special to do about it all my Mercedes been like this. But never grease to much only little bit on where the pads slide AND NOT BWHIND THE BRAKE PADS WHERE THE PISTON TOUCH like some suggest what I seen and read don't do it.
it will build up dirt and only give problem this area should be clean tbanks