ABS kicks in when slowing down

[RanjS8]

I changed my rear brake discs today...and decided to give the abs sensors a clean....I didnt have a problem before, but i decided to clean as when i cleaned the front sensors the gearbox became so much smoother....

Well anyway...after cleaning them and putting them back in...i got that problem that is caused by a dirty sensor.....when i slow down to a stop the abs kicks in...very annoying....

Was wondering does anyone know how far the sensor is meant go in to the hole....i m thinking i push the sensor too far and possibly damaged it...but i dont have any abs codes or abs warning lights...so not sure why i m getting trouble....

any ideas would be appreciated???????????