desperado213

I've had this problem for a while and it didn't bother me much at first but now it really does.

So when I push the brakes there is a grinding sound when the plunger depresses. It almost sounds like sand or dirt is inside the rod or something like that. The brake fluid is full and the pads are only like 3000 miles old so i think the problem is with the pedal or plunger just not sure. Please help!