I had a bad clunk in the front of my `96 1500 and it turned out to be a broken spring. Your brake fluid could be leaking out the back seal of the master into your brake booster so you won`t see it on the ground. I have seen boosters 1/2 full of fluid!

 

that's good thinking!!! i did see, once, a wet spot on the ground, but it was dry so i couldn't tell what fluid it was. it was in the area of the driver's wheel. but only once. everything looks dry. going to see the mechanic on saturday. he's pretty good but sometimes you have to hold people's hand.

i don't think the spring is broken. it had to be removed to replace the shock. i think it would have been noticed.