The past couple weeks I have been noticing this on my 95 Ranger (see sig for specs). The brakes are pretty new (rotors and pads in 10/2008) so I dont think it is that. I do know that the wheel bearings for the fronts (2WD) are going as well as the universal joint. I plan on replacing them pretty soon, when I have a few nice days where I can ride the motorcycle to work and can butt it up against a weekend so I have extra time.
Since I got on a tangent, here is the problem... it seems that about 40% of the time when I go to apply the brakes after a few seconds the brake pedal gives and the anti-lock pump thing kicks on. It doesnt do this all the time and it doesnt cause me to loose total brake control, it just makes it slower for me to come to a stop. This isnt because I'm on any slick or icy surfaces because it has been pretty hot and dry in the area as of late. I gotta bring it into the shop so I plan on getting the whole bearing thing taken care of as well.
This happens alot at low speeds and I dont notice it to be at a specific speed nor is it only when I hit the brake, I sometimes hear it when my foot isnt even on the brake, thats when I know not to hit it... and if I need to I do it very gently and make sure I dont "SLAM" to a stop or dont stop in time. (get rear ended or rear end someone) I asked my neighbor what he thought it could be (he owns a shop) and he told me he'd take a look at it, but it could be anything from a cheap sensor up to something that could cost upwards of $1000. This problem has been happening for the past couple weeks and only today I noticed after driving alot the ABS light finally came on the dash. It went off after I shut off the truck and restarted it, then drove another 20-30 minutes without any lights.
Any guesses as to what the problem could be?