I have a leak at my fuel line pump i.e.constant drip (outside boiler). this is where the fuel line splits joined by a threaded connection. The problem I have is the threaded part of the joint is so small in length that i can barely get any of the sealant tape on to the threads available. If I do get it on the the thread there is no way I can get the connecting nut to fasten.Is there any other way I can stop this slow drip of fuel, any advice would be very much appreciate, thank you.