Braking shudder in pedal, accompanying whir
 

When I am braking and I have almsot reached a stop I sometimes feel this shudder in the pedal and hear a whir like a pump or servo going. its really strange. I can feel it in my foot on the pedal and it kind of freaks me out a bit. Anyone have any ideas....??

sounds like your anti lock brake system at work, are you driving on snow / ice ?

it does seem to hapen when I am on a less than perfect surface but it also happens with just a little bit of water and whatnot. Its not the typical shudder I am used to that happens at the wheel with most cars. this is like its attached to the pedal.

It is either your ABS kicking in, or you have a rotor that is warped. If there is a whir accompanied with it, I would lean towrds ABS...

Have you checked your pads?

Start with the basics, what year and model?
When was the brake fluid last changed and have you been getting any brake warning lights on the dash?

My truck has done that ever since I've owned it for the last few years. I sounds like the abs pump kicking even, but it doesn't actually affect the brakes (at least like the abs normally does when it kicks in). I think the pedal does vibrate a little for a second or so just as I come to a stop, even on dry pavement. I definitly have the humming sound, I always thought that it sounded like a cd changer switching disks under the dash. I'm not sure, but I think it happens more often when it's cold out. It never seemed to affect anything and the abs light (3 amigos) have been off until about 1 month ago when they all showed up. I never did figure out the noise and the very slight pedal vibration and I'm not sure why my 3 amigos are lite up now.

By the way, I have changed and bled the brake fluid out. It didn't help, although I've read that to properly bleed the brakes you need to hook it up to testbook and activate the abs valves. I'm not sure how necessary this is.

Without knowing the year of the truck we cant help you.

99 (US Spec) Disco SD(Ser 1), 75k mi on the clock.

Sounds to me like typical D1 ABS actuation. Is your anti-lock light on?