i have a 4x2,v6 2000 model. when coasting around 5 to 15 mph and i apply my brakes,i hear a thumping sound to the left of the pedal. it sounds like it's coming from behind the left end of the firewall. i also feel my brake pedal vibrating a little bit. it does that for 1 to 2 seconds and it functions normal. my local dealer hook it up to their computer to check the abs and can not find anything wrong with the system. pls help.

 

My guess, a lump of rust catching the brake pad or warped rotor on l/h front. If you can find a shop with a dial gauge, have both rotors checked for thickness and runout (warpage). These specs are wicked tight, a warp of .001" is maddening because it's hard to track down. If you can't find anything else, swap the rotors sides or just replace them.