farmer11, I'll try to help you, With the oil pump removed, take the piston out and spring. Now when you look inside you will see an aluminum center that the piston pin goes into, this will pull out with a good pair of needle nose pliers. Make sure you have a clean work area. Carefully pull it out and there is a spring and a small ball in the aluminum cylinder. DO NOT LOOSE THESE. Now you can spray a cleaner into all the holes and clean up. You will see holes in the Aluminum cylinder and also the ones on the plastic body to clean. Blow these out with compressed air. Replace the alum cylinder with the holes that are in the sides so they line up with the holes in the plastic body. You can't see the holes in the body but you can see on the outside where the factory drilled holes and plugged them up. After assembly put oil into the oil holes on the oiler and pump the piston and it will work and pump oil so you will be assured it works without having to reassemble. If it works put it on. I 've done hundreds of these and almost never had to replace unless a warped Plastic body. Tony