ABS problem but NO CODES or Light

I have a 2000 S-10 P.U. 4x4 exten Cab 4.3L I have promblem with my ABS system. There is no codes and communcate with a scanner that has abs capiablet. At dead stopm it reads 3-mph, then all 3 of them goes up or down together at the same time. But when apply the brake slow or quite the ABS start to activted and the truck will not stop, it getting worse all the time. Even on dry day and pavement. I already replace the left front hub and sensor also the right front pick up sensor. I only have 72K miles. Should I replace the ABS Realy and rear Wheel ABS sensor. Ther is only one for the rear. I brought to a qualifer shop to see if they could diag. It. But there is no luck for them. They said replace the both front hubs and rubber brake lines. With factor parts. It will cure my problem. I think it could be the relay because it defected for over a year and then I replace the the left front front hub. Put I had a code for both front senors. Could I have over heated the relay because of the long priod of time not working and leaving the sensor unplug. So NO CODES but still promblem with the truck stopping went ABS activates.