Pads sticking to rotor

[AKPS4]

Anyone have this happen? I have new stop tech trophy kit with the stop tech pads for now. Rear brakes are stock (have new pads and rotors waiting to install) 40k miles on car.

I recently noticed, after installing the trophy kit, that the pads stick to the rotors. I can't tell if it's the front doing this or rear. Seems wierd because pads should retract back and not be stuck.

Could it be the parking brake not releasing? This usually happens when it's hot and humid out.

[Victor Newman]

It's one of two things for a fact:

1) the pad compound

2) not enough grease to allow pads to slide - retract

I had the same thing happen to my car when I installed the ST60 kit and stoptech pads. The pads bonded to the rotors overnight after I drove the car in the rain or washed it. It happened when the pads were new, and when they were 50% used. They would leave pad imprints on the rotor, then I got bad judder. The pad compound is not abrasive enough to clean the rotors between that time and the next, so they get worse over time. I finally removed the pads and installed Hawk HP+ pads, and did it myself so that I could ensure that they were greased properly (the stoptech pads came out with some moderate tapping from a hammer - so I'm not sure if the shop that originally installed them did a good job). The HP+ pads are abrasive enough so that they cleaned my rotors. Judder went away, and the rotors are a nice even gray color with no marks - pad imprints or shiny spots. Everything works great now. I'm thinking that even Hawk HPS pads would clear it up, as that's what I was running in the rear previously, and they kept my rear rotors a nice consistent gray.

But it's one of the two. If you're sure the pads were greased properly to allow movement, then it's confirmed that the pad compound sucks and to get a different pad.

[hotleadsingergu]

What do you mean "stuck to the rotors"? Do you mean they're dragging? Do you mean it looks like the pads are on the rotors? Are you getting errors?

The pads will never not make contact with the rotors. If they did, it would be a problem. If there's too much pressure on the pads, so that it always feels like they're braking, then it's probably a bigger problem than just installing them wrong. If the parking brake weren't releasing you probably wouldn't be moving anywhere...it fully-engages the rear brake.

[Victor Newman]

You can see pad prints and glazed sections

Before:

[Victor Newman]

And this is a quick one I just took:

[Bruno_s4]

I had an issue with my first Generation Stoptech ST60 kit on my B7 S4 but it was caused by corrosion buildup on the caliper sliders.
What happened was going through winter after winter corrosion started between the caliper and the aluminum slider (that the pad slides down).
This made it extremely hard to remove the pads because the slider was pinching them.
I started getting CRAZY shudder on the hwy that would come and go because the pads would make constant connection to the rotors.
It puzzled me (and a couple mechanics) for many weeks until I figured out the problem.
After many discussions with Stoptech (needed to climb the ladder to Senior Management) they swapped out my calipers for an updated version that apparently does not suffer from this problem.

[AKPS4]

I don't think I have corrosion issues since these are brand new. Thinking it's the pad compound/grease issue.

What I mean by stuck is that they are literally stuck on the rotor but become free as soon as I move, of course with a nice little sound

[Victor Newman]

I don't think I have corrosion issues since these are brand new. Thinking it's the pad compound/grease issue.

What I mean by stuck is that they are literally stuck on the rotor but become free as soon as I move, of course with a nice little sound

That's exactly what I had, and my kit was brand new, purchased in the summer, in the south. Definitely not corrosion. That, and the problem IMMEDIATELY went away when I changed pad compound and made sure the pads were greased. Didn't touch anything else other than those two factors.

In the morning, I'd try to back up, the car wouldn't move, then "POP", and would start rolling.

[AKPS4]

Yup. Ok great to know. Going to order new pads ASAP. Good thing these are a piece of cake to swap out.

[cspcrx]

It is a perfect outline of the pad. Is it the compound on the edges of the pad that is being left behind? If so sounds like they have an issue with that bonding material that they line the edges of the pads with.

[AKPS4]

^good point. You can clearly see an outline where the pad gets stuck to the rotor.

Can someone direct me to what size/style pads I need - need street use only right now. Much appreciated, this kit is new to me so just figuring it all out.

Thanks

[RyanJon]

Is this happening all the time or just when they are red hot?

[AKPS4]

I don't see a pattern related to hot rotors. It's really hot and humid or wet ambient.

[Victor Newman]

I'd recommend Hawk HPS. I had them in the rear when I originally got the ST60 kit, and they were great. I was only having a problem with the front. HPS will be slightly more abrasive than the stoptech pads, so they will clean up your rotors if they haven't gotten too bad yet with the pad prints, but they'll be easy on the rotor over the long run. Dust isn't great, but they're going to feel more like the OEM pad, and I've learned (even with my HP+ pads, that have a lot of dust) you can just spray the wheels with wheel cleaner, let it sit for a couple of minutes, and spray with a hose, and you're 95% dust free again in 5 min.

If you want them to be silent for the street, don't get the Hawk HP+ pads. They are phenomenal, and I love them, and will buy them again personally, but you've got to learn to ignore the squeal at low speed.