Hi, all

A few months ago I was on a long trip in my 88 300 sel and I got a vibration much like an out of balance tire or a tire that was coming apart etc.. As I was about to pull over the vibration slowly went away. So I stoped at the next convenient spot and looked over everything. Didn't see anything wrong just looking at the brakes, tires, suspension, etc..
So I continued on my trip and never had any more trouble out of it.

Yesterday, I made short trip into town, and the vibration started again at 50-60 mph after driving this constant speed for several miles, and just as before it went away within lets say 30 seconds. I drove it pretty hard on the way back trying to rule out a transmission problem, etc.
And when I got home the brake pedal would almost mash to the floor. I got out and could smell something burnt. After checking it out I found that the right wheel was a good bit hotter than the others, you could put your hand on it but it got quite hot.

Jacked it up this morning, front wheels would turn. Got in it and cranked it up pumped the pedal several times. Right front wheel could barely be turned using both hands on the tire.

So obviously there is something wrong with the right front brake caliper now, but what caused the problem and where did the vibration come from? Should I be looking at other sources for the vibration problem? Or was the intermittent vibration the sign of the brake caliper or something else in the braking system going awry?

Any help appreciated.

BMJR