Weird brake pedal feel?

[Lee'sdaytona]

Hey everyone,
Just today, I noticed the brakes on my minivan doing something strange. For starters, they have never been extreamly tight...but they worked well all along, probably as good as stock minivan brakes should work. BUT, now when I press the brake, before it begins to catch and tighten up, it feels like something is rubbing....you know how the pedal should press down smoothely then you feel it start to catch? Well it doesn't go down as smoothe....almost like something is wrong with a seal in the master cylinder or something....I don't know if its anything to worry about....I did notice the fluid is slightly low, but it does still stop, as I tested it on a pretty hard stop. No leaks that I can see.
-Lee

[looneytuner]

i'll guess the calipers are riding on built up crud in the bore. If so, I'd replace them. I did brakes 40 years ago and we always rebuilt the cylinders so the customer wouldn't come back with them leaking on new linings. the cylinders and seals were good buy they wind up sliding on the crud when you push them back with new pads and shoes.

[Lee'sdaytona]

Yeah that makes sense. Weird that it just started doing it. I put about 500-600 miles on it before noticing this. The owner before me said he replaced the pads....don't think he replaced the calipers though. I was a bit concerned that it was the master cylinder starting to go (ie, the seals in the master cylinder) but it makes more sense for the seals on the caliper to get crud on them.
thanks,
Lee

[Lee'sdaytona]

What is a good diagnostic proceedure to make sure the caliper is my issue? I guess look for fluid around the caliper/rear drumb cylinder?
-Lee