We have fitted a big brake conversion to our VP series 2 wagon which has ABS. This system consists of :- 1 x VS Commodore booster unit 1 x VX Commodore master cylinder 2 x front wheel adaptor hubs 2 x VT - VY front calipers 2 x DBA 300mm drilled & slotted (gold) front discs 2 x DBA standard size drilled & slotted (gold) rear discs 2 x standard issue rear calipers It has the standard ABS control unit in place which doesn't function properly when the fuse is in place (the brake system behaves like a non ABS system when the fuse is removed). The problem we have with it is at a certain road speed (i.e. when the car crawls to a halt) the ABS goes haywire,a large vibration is felt through the firewall and the pedal is pushed up which renders the brake system inoperative at those road speeds,this happens regardless of how hard the brake pedal is pressed. People on the PF website said to remove the ABS fuse which we did,and this did fix the symptom,but not the problem,the problem still exists as we have merely isolated the problem. Can anyone tell me what the problem may be? I am not sure if is due to a damaged sensor,incorrect air gap between the chopper and magnetic pickup or whether it is something to do with the program in the module (i.e. somehow thinks the wheels are about to lock up due to a certain change in voltage). I don't know about in the Holdens but I read that in the Fords the ABS system is rendered inoperative if a sensor is damaged. Note we did all the stuffing around with the actuating rod in the VS booster (i.e. shortening it) if anyone mentions,as it is too long to just bolt the VX master cylinder straight onto.