Hi , i have a 300 tdi in a defender 110, the leakdown pipe from the rail to the pump has been replaced but keeps blowing off and splitting. no blockages in rail, all injectors working and i removed the banjo bolt and cleaned it ___ i thought it was pressurising from injector side but its shooting out of the banjo end back up towards the leak down rail , on for a few seconds then off for a few then back on. I thought the flow was from the engine to the pump then to the tank as an overflow, not the other way. Whats behind the banjo bolt and how is this happening, any help appreciated