OPERATION N° D. IE 112-0: Adjusting the valve rocker clearances 10. If valve rocker noise persists after adjustment, proceed as follows : - Remove the battery - Slacken the alternator and the H.P. pump ting bolts. Disengage the belts from the drive pulley. - Engage the parking brake - Remove the nut securing the drive pulley (1) and withdraw the pulley as far as possible towards the front.