Input requested from anyone running AP race brake kit with DS2500s

[Yetti]

Recently bought a used AP Racing sprint brake kit for the front of my FRS when I got the kit I put in a new set of DS2500 brake pads. Now when I apply a certain amount of pedal pressure (not much probably like 15%) and are under a certain speed slowing down (like under 20 mph) it squeaks like crazy.


I don't get it I had the exact same pad compound (DS2500s) on my stock calipers and they didn't squeak at all. I was thinking of spraying down the rotors and pads as maybe the previous pads (hawk HPS) left some brake dust that is interacting with them? Also today at AutoX when driving at full attack they don't seem to squeak under the same conditions. I would like to blame it on the pads just squeaking when not up to temp although if that is the case then why were they so quite before in the stock calipers?


Anyone running AP Racing Spring brake kit on their car with DS2500s what is your experience?

[new2subaru]

Originally Posted by Yetti

Recently bought a used AP Racing sprint brake kit for the front of my FRS when I got the kit I put in a new set of DS2500 brake pads. Now when I apply a certain amount of pedal pressure (not much probably like 15%) and are under a certain speed slowing down (like under 20 mph) it squeaks like crazy.


I don't get it I had the exact same pad compound (DS2500s) on my stock calipers and they didn't squeak at all. I was thinking of spraying down the rotors and pads as maybe the previous pads (hawk HPS) left some brake dust that is interacting with them? Also today at AutoX when driving at full attack they don't seem to squeak under the same conditions. I would like to blame it on the pads just squeaking when not up to temp although if that is the case then why were they so quite before in the stock calipers?

Anyone running AP Racing Spring brake kit on their car with DS2500s what is your experience?

I've run them in the past. You would benefit from bedding them in.

[Walldodger]

I have the Essex Sprint kit, I assume you have the same one. Mine squeak too, but I do have high temp pads that squeak on just about anything.
If it is an Essex kit, they do sell retaining springs that put pressure on the pads to reduce noise. They're quick to bolt on. But bedding them in is still definitely a good idea.

[autoracer86]

I saw similar issues with my brand new brembo bbk and new pads. Took a fair amount of driving both normal and hard stops to finally get everything bedded in and working probably.

[cmiovino]

Originally Posted by Yetti

Recently bought a used AP Racing sprint brake kit for the front of my FRS when I got the kit I put in a new set of DS2500 brake pads. Now when I apply a certain amount of pedal pressure (not much probably like 15%) and are under a certain speed slowing down (like under 20 mph) it squeaks like crazy.

I don't get it I had the exact same pad compound (DS2500s) on my stock calipers and they didn't squeak at all.

I had the EXACT same issue with the DS2500's and my Brembos. Here's a video:

The similarity here is the AP Racing kit and PP Brembos are fixed calipers. Fixed calipers inherently create more noise, then you toss in a bad that's more about performance and less about day to day driving. I even had some Girodisc backing plates and regular grease to help, but it was still that loud.

The solution is that red CRC brake disc quiet stuff. Either the spray or the "goop" liquid version. Many of my autocross buddies use the goop, I use the spray. I cake mine all up on the back in the spring and it usually lasts until the next spring (car is stored over winter). Car sees about 25 autox events and 4-5k street miles. If it's really cold, you might get a very very slight squeal at 2mph. It fully fixes the issue.

If you're tracking it a lot, you'd have to use this and see if it burns off quicker. You may need to reapply more if you're really cooking them on track. The CRC product dries up over time and with heat.

[new2subaru]

Funny video!

There's always the option of swapping out to a street pad.

[Yetti]

Thanks for the feedback, glad this is more normal and not something wrong. As for the disc brake quite goop that can take track days?

[cmiovino]

Originally Posted by Yetti

Thanks for the feedback, glad this is more normal and not something wrong. As for the disc brake quite goop that can take track days?

I'd just try it and see what happens. At autocross, our brakes don't get much hotter than street driving. For me, it's the number of heat cycles that does it in over the year.

I could see one track day with high caliper temps doing it in. But who knows, maybe not.

[JRitt]

The key is to keep your discs bedded in properly. You need a pad transfer layer on the disc, and that should quiet them down dramatically. Please see these videos:

[bhmax]

I had the same experience a few years ago running specific pads on both the stock brakes and the Sprint kit. Curious how much the new pad retention kit helps out as I’m looking for another brake kit.

[Yetti]

On the topic of removing previous pad material would 4 big Autocross events be enough? I realize this kit in general is overkill for braking in a FRS. Anyone document a time frame they had to work through to get everything worked out?