Early Bronco Knowledge Base Explore more early Bronco tech and history articles in the WILD HORSES Early Bronco Knowledge Base. Return to Base Early Bronco Knowledge Base Early Bronco Power Steering Pump Pulley Tech Pump Pulley Tech All of WILD HORSES's Delphi pumps use a .750 shaft with a press fit pulley. The stock Bronco Power Steering shaft is approximately .690 so the pulleys are not interchangeable. If you are going to be removing and installing pump pulleys, we recommend one of our pump & alternator remover & installer tools. Serpentine Pulley Tech The serpentine pulleys come uninstalled. You will need to mount the pump to the bracket before you can install the serpentine pulley. One of our pulley remover & installer tools will be needed. Power Steering Fluid Tech For the best possible performance, WH recommends using power steering fluid (not ATF) in all of our steering components. Shop Early Bronco Power Steering