Braking problem- again...

[wildo]

Ok, so I can no longer live in denial that I have a problem with my braking system. As some of you may know from a previous thread (which sorry- I wasn't able to find) I replaced my front brake pads, and am suffering poor braking since.

So today it rained. After I drove my car home from work today, I noticed some odd surface rust STILL on the rotors. What is odd is that it's the same both driver and passenger side.

Has anyone ever experienced this before? Anyone have an idea of what could be happening here? Notice in the pics that the pads seem to be seated just fine...

No wonder it feels like half my brakes aren't working- cause they aren't!

 

[dxaveP5]

have you checked the pads itself?
like take the pads off, and try rubbing it on concrete, to clean it off to make a somewhat even surface or the krap sittin on the pads and see if that helps.
usually thats what we do when pads glaze, so iono if this will help.

 

[TheMAN]

did you turn the rotors? are the sliders lubed? have you EVER bleed/flush the brake fluid?

 

[pro5turbo]

Now i had that problem, that after a good rain, i would have surface rust on my rotors. I thought it was normal...BUT, from your pictures, it looks as if your pad is not making full contact with your rotor, which will give you the impression that the brakes aren't working.

What you may need to do, is inspect the calipers to see if the piston isn't cocked to the side or at at angle. The piston should come straight out, so you may have to take off your calipers, push the piston all the way back in and bleed your brakes and try again.

 

[wildo]

I FINALLY had time to look into this problem. Though I haven't yet taken it for a drive- I believe I was able to locate the problem. Apparently (this may be common knowledge, but I certainly never heard of it) the brake pads I got had a specific side. I mean, a specific pad had to go against the caliper piston, and a specific one had to go in the carriage.

The problem is that the pad that had the wear indicator (the tab that squeaks when the pads get low) also had two little molding spurs that caused the top side of the pad to sit out from the carriage. If I reverse this specific pad to be on the caliper side, then these two spurs don't make contact with anything and the pad sits flat.

See in the first picture, if you look really close (much easier to see in person) you can see two little dots. In the second and third pics, you can see the spurs causing the problem. The fourth pic shows how the opposite pad does not have these two little spurs.

 

[Clarkbug]

Are those Wagner Thermo-quet pads by chance? I think I put some of those on one of my P5's a while back....

Anyway, the "spurs" are meant to be there to hold the shims for the pads on. You typically pry them off of the OE pads and put them on the new ones, and those dots help hold them on when you close the caliper over them. But without the shims, you can run into the issue you described. You can run without the shims, but if you start to have really squeaky brakes, the lack of shims can contribute to the problem.

 

[wildo]

Are those Wagner Thermo-quet pads by chance? I think I put some of those on one of my P5's a while back....

Good eye! Yes they are...