ABS Problems 2000 ranger 4x4

I am having a problem with the ABS on my 2000 Ranger XLT Sport 4x4. Every time I try to stop at low speed, the front ABS kicks in and the truck will not hardly stop. Luckily I have not hit anything yet, but I am worried what might happen in a panic stop situation. I pulled the ABS fuse and the brakes worked great, but the ABS light stayed on and after about a week the check engine light came on. I replaced the fuse and reset the engine light and the brakes were back to not working right. I bled the brakes at all wheels until the system had all new fluid, which still did not solve the problem. I have read that the anti-lock pump must be bled seperately and that a special tool is needed for this. Has anyone else heard of this? The front brake pads were replaced last fall and I made sure that the slides were clean and lubricated. The truck only has 43,000 miles. Does anyone have any ideas?
Thanks

Do you have a four-wheel ABS sensor or just one at the differential? Is your speedometer working OK? The speedometer works in conjunction with the ABS and one symptom of ABS problem in addition to the CEL is that it is erratic at lower speeds.