Damage to Fuel Tank
There are dents and scratches in the tank, but the first major problem to address is that the connecting stub of the fuel line was broken off.
I tried aluminium brazing. I had the broken off stub. This did not work. The tank soaks all the heat away from the braze area. The aluminium brazing rod just melted and made little blobs on the tank. Also, the stub, because of it being much smaller would overheat and burn through.
I thought about TIG welding but gave up on that; I would have a similar problem. Because of the size difference, the stub would probably burn through.
My next attempt was to tap a M7 thread down into the fuel line, put a matching thread on the outside of a suitable OD copper pipe and screw it in. I did a test and it worked; no leaks. But I'm sceptical about this. There's a lot of vibration and it may come undone.
The next stage of the plan is to make a M10 connector, a 6mm hole through to accommodate a short length of copper tube. Then cut the aluminium tube from the fuel pump and join it to the inside-tank copper pipe with fuel hose and clamps.
I tried aluminium brazing. I had the broken off stub. This did not work. The tank soaks all the heat away from the braze area. The aluminium brazing rod just melted and made little blobs on the tank. Also, the stub, because of it being much smaller would overheat and burn through.
I thought about TIG welding but gave up on that; I would have a similar problem. Because of the size difference, the stub would probably burn through.
My next attempt was to tap a M7 thread down into the fuel line, put a matching thread on the outside of a suitable OD copper pipe and screw it in. I did a test and it worked; no leaks. But I'm sceptical about this. There's a lot of vibration and it may come undone.
The next stage of the plan is to make a M10 connector, a 6mm hole through to accommodate a short length of copper tube. Then cut the aluminium tube from the fuel pump and join it to the inside-tank copper pipe with fuel hose and clamps.
Cutting through the aluminium tube inside the tank would be an easy job for a dentist. Think hard before tackling an inside-tank job; you can't see what you are doing, you can get only one hand into the tank, and there are no tools made for this kind of job.
It's not possible to cut the pipe inside the tank with a hack-saw blade or tube cutter. I guess a dremel tool will work, but it has to be small enough to get through the filler hole in the tank.
This is the tool I put together for the job, a flexible drive with a small cutting wheel. I used an old angle grinder cutting disk. It's difficult to centre the disk on the home made arbor. I ran it against the grinding wheel to compensate for the off-centre mounting and also to reduce the diameter.
Positioning it is a challenge. You have to work by feel and sound. Fortunately once a cut is started one can position the cutting disk by feel. Cut part of the way through and break the pipe off.
It's not possible to cut the pipe inside the tank with a hack-saw blade or tube cutter. I guess a dremel tool will work, but it has to be small enough to get through the filler hole in the tank.
This is the tool I put together for the job, a flexible drive with a small cutting wheel. I used an old angle grinder cutting disk. It's difficult to centre the disk on the home made arbor. I ran it against the grinding wheel to compensate for the off-centre mounting and also to reduce the diameter.
Positioning it is a challenge. You have to work by feel and sound. Fortunately once a cut is started one can position the cutting disk by feel. Cut part of the way through and break the pipe off.
This is the connector gadget. I tested it for leaks before installation - 5 bar - You don't want to go through the contortions of fitting it and then discover a leak.
I made two plastic washers. I used some material from a 5 litre oil container. I figured that should be fuel resistant enough. Two washers and two nuts completes the assembly.
It's a job getting the whole thing together, but finally it's all in place.
Inside the tank - Rubber fuel hose connection between the old aluminium pipe and the new outlet point.