I tried to rebuild a CAV pump myself on a 1969 Ford 3 cyl. Dexta (2000). There was an Australian chap on a YouTube video that made it look like a piece of cake. I ordered a rebuild kit, took the pump off, disassembled it. I soaked it in carburetor cleaner, blew it all out with compressed air and reassembled it. I put it back on the tractor, tried to bleed the air at the injectors and nothing. Fuel was getting to the filter, through to the pump, but not to the injectors. I thought the fuel shut off lever was sticking, but it seemed free. Finally, threw in the towel and ordered a Professionally rebuilt pump from a fellow in Kentucky. Put it on, primed system, engine started and runs like a champ.