Bad master cylinder or vacuum booster?

[ChrisK]

Lately, I've noticed that it takes much more effort to stop my Jeep. Yes, I know bigger tires will do this and yes, this was happening before I installed the S-10 calipers. I thought maybe it was just in my head so I had a friend drive it. He agrees that there is a problem. I then drove his and it stops much easier even with his 37s. The brakes just don't feel very powerful. I can't lock them up at all no matter how hard I stand on them. My friend can lock his up easily. We re-bled all 4 corners a couple times and it still is no better. We made sure the rears were properly adjusted and still no better.

What we fdid find is that the area on the front side of the vacuum booster (where the MC bolts to it) has fluid on it. Not enough that it is dripping, but there is definately fluid there. We pulled the vacuum line to the booster and we could hear the air going in (out?) so it is pulling a vacuum.

So, is it the MC or the vacuum booster or (dread) both? If it is the VB or MC, are there a better ones out there other than Chrysler that are direct bolt ins? Why put back stock parts when better ones exist. My future plans call for rear disks and WJ front calipers if that helps.

Chris