1995 Windstar- ABS engaging at while trying to stop at slo..

I have a Windstar with114k miles. Thankfully, it has been a pretty
good van for us. Only recently I have to put some money into it.

When I brake to slow down, these brakes work fine and when I get close
to complete stop, I hear a clink and it feels like that the brakes are
not working. If I take my foot off the brakes and press again, it is
fine.

I just had my rotors, pads etc. changed to fix this problem. But that
was not the problem. My gut feeling is that the ABS is misbehaving at
that low speed. I had to change the "gear" in the ABS a few months
back because it was worn out (the mechanic showed me). Not sure if the
same one is causing this.

Questions for experts :
1. any other cause?
2. How to turn off ABS to test my theory? If this is the problem, can I
keep ABS off? I don't want to spend too much money on this vehicle.

Thanks,
AKG
Chicago