I realize that this is a shot in the dark but I will give it a try. I have an 07 RL with 60k. I have owned it since June and I haven't really stepped on it yet. The other day I was on a long entrance ramp so I thought I would open it up. I;m not a race car driver, I got it going to about 90 before I backed off to merge and be normal. I didn't brake hard at all, just coasted and applied a little brake. About a 1/2 mile later I heard a weird sound coming from the drivers side. It sounded like it was underneath my seat and all I can say is it was a large hum that was foreign to me since I have been driving the car. About a mile later I got to my exit and I applied the brakes and my steering wheel vibrated violently.

This continued until I got where I was at. The front brakes and in particular the drivers side smelled like I had been stepping on them, they were very hot. There also was a hissing sound coming from the area of the master cylinder.

I let the car cool down for an hour and then went to drive it and it was normal, not problems at all. I am a little afraid to try and replicate this but what is going on? My guess is the drivers side caliper locked up slightly for some reason. Maybe the brakes got hot and were over expanded? That sounds stupid but im reaching here....

 

Symptoms do point to the caliper locking up, could be wheel bearing, or other things. Take the wheel off and look around, report back what you see.

 

Does the brake master cylinder recall apply to your car, and has it been performed if so?

 

As An Acura Tech What It Sounds Like To Me Is You Warped The Rotors Slightly. Basically The Hotter They Get The Worse It'll Feel When You Hit The Brakes And More Often Than Not The Faster You Drive Say Slowing From 60+ You'll Feel The Vibration/Noise In The Steering Wheel Due To It Transferring Through The Steering Components. All You'd Need To Do Is Get Your Rotors Resurfaced Preferably With An On-Car Lathe