I have a 1997 Acura RL in my shop and when the temperature is cold outside the ABS pump makes a growling noise when the pedal is depressed. Sometimes I get a fault code and sometimes I don't. The car has 83,000 miles on it and the brake fluid looks fine. Do you think the ABS pump or motor needs to be replaced?

Hard to tell from here but if you can reproduce the growling noise by taking off the motor and running in cool conditions off the vehicle that might be a method. If it works fine then replace the pump. What are the codes you get when there is a fault?