hey have a 92 2.0 dohc sierra, when driving at normal speed 30/40/50/60 etc and you hit the brakes the brakes work perfectly, but when at low speed in traffic etc and coming to a stop when you press the brake pedal the abs kicks in and the pedal vibrates away,

the abs fault light isnt lit up on the dash

any help would be greatly appreciatted!

thanks in advance