My '99 3500 dually has the hydraulic brake booster system. A couple of weeks ago, while driving on the interstate, I kept smelling, what I thought was the 18 wheeler in front of me, burning brakes. When I was exiting, I applied my brakes. They felt VERY stiff and when I slowed into traffic, without the big truck in front of me, I smelled the burning real bad. I pulled over, my left front was real hot, luckily not on fire. I found that when I pulled the pedal up with my toe, there was no burn. I took the whole front brake assemblies apart, cleaned and inspected them, no visible problems. There was no problem after that, so I thought I fixed it, maybe the brake parts lube made it stick or something. After about a week the same thing, with the right side doing it this time. ARRRRGGGGG! Reading my Haynes' doesn't tell me anything worthwhile. Does anyone have a clue? Is it my master cylinder or my booster? HELP!!!!