Pingel Oil Filter Screen Kit For Twin Cam Oil Pumps For Harley Features This is a screen to protect the oil pump if one of your cam chain sliders fails and falls apart It rarely happens but it can and if you lose a chain tensioner you have enough troubles, but this little screen filter will prevent the further loss of a oil pump by keeping debris that would have been missed by the oil filter Comes with 2 screens and the installation tool Remove oil pump from engine or take new oil pump and disassemble it Using a 1/2 drill bit or preferably a 1/2 reamer, enlarge both scavenger ports Drill or ream approximately 1/4 to 3/4 in depth After drilling or reaming, clean up all the edges with a small knife or sharp object Clean all loose material from the pump housing and scavenger ports Place screens in the scavenger ports cap side down using the tool supplied Drive the screens into the ports 1/4 to 1/2 Reassemble the pump and install according to the manufacturing instructions