Thanks for all the support.
When I said I pumped my brake, I should have clarified that when this problem happens I let off the brake and hit again I have good brakes.
I've never heard of warped rotors doing this, is this because of ABS sensors? I'm going out to the truck in a minute and check the fluid and vacuum lines. This weekend I'll give it a more extensive going over.
Thanks again guys
See ya
Capp/Mark

 

i dont think its warped rotors. if they were warped, they would feel like their grabbing and letting go simotaniously (i think i spelled that right). this problem is more like the pads arent even getting to the rotors from lack of fluid/pressure.

 

It's full of brake fluid, and the vacuum hose looks alright as well.
What should I look at next?
Capp/Mark

 

hmmm. is there fluid getting through? pinched/bent lines anywhere?

 

I found the problem. I had a friend scan it with his Snap-on analizer, it said that the left front ABS sensor was bad. At first I cleaned it, but that made it worse. I bought a new one and now there is no problem. Thanks everyone for all the help.

 

Well , I was way off. Glad you got it fixed.