It's an old thread I know but the squeak is actually the white plastic plunger under the boot. The boot will pop right off at the firewall side and you can smear the grease that's in there already or use some di-electric grease. I just smeared the grease in there and pushed the pedal in as far as I could to coat the inside and the squeak is gone. Best guess is the grease used is to light and a thicker grease will probably cure completely. I will put that theory to the test if/when it returns. Hope this helps anyone in the future.

 

I'm having this same noise and its really annoying. I think I will try the grease before taking back to dealer. However, it will be going back soon since the water pump is starting to make noise again after being replaced a few months ago.

 

I know this is an old thread, but I ran across it after Google searching "Jeep JK Squeaky Brake Pedal." My '14 has been doing this for months. I just took it to the stealership for the 2nd time about this obnoxious squeaking noise in my pedal that was driving me crazy. The first time, they shot it with WD-40 and told me it was fixed, but when I pulled out onto the highway, it was already squeaking again. Today they finally fixed it. Just as I read on here, they said the problem lies with a white Teflon bushing that is on the brake pedal rod beneath that rubber accordion boot near the firewall. Teflon is noisy they claim. They added some grease to it and the problem is gone. They indicated that they were a little surprised that Dodge has not issued a Technical Bulletin on this issue because they see it a lot (it could come out in the future). They just told me that if it ever started again, bring it by and they would add more grease. Hopefully it will not act up again for a long time. Just wanted to share the news with everyone.

 

I used some silicon dry lube right inside the rubber boot at the firewall behind brakes pedal. Easy fix for my creaky floor.