Datsun Roadster Forum-311s.org

Tank has to come out of my 69. Drained it and it's been weeping black sludge for the last 4 hours. Pump won't pull gas. Tried using 125 psi air from pump back, it's blocked solid. Anyone direct me to a thread detailing the steps? Assuming you have to drop it a little to get to the inlet and vent lines? I can't get an angle on it flat on my back. Can't find any videos online.

Best to drop the tank completely and then try cleaning the tank itself or having it professionally boiled out and sealed. Radiator shops can usually boil them out. There is a chain called Gas Tank Renu but they are expensive. Once the tank is out disconnect the fuel line at the fuel filter in the engine bay. You can try blowing air now to see what happens. Carefully pour lacquer thinner into the clogged fuel line. If you do this a day before you begin it allows time to help dissolve the clog. If you are really clogged up get some 1/8" wire strand cable-probably 20 foot to be safe from the hardware store. With the wire in as far as it could go cut the stranded wire approximately 6" from the fuel line opening. Pull the wire out and attached the other end into the cordless drill. Feed the wire back into the fuel line and slowly began drilling into the clogged area. Very important: Because of the spiral direction of the stranded wire make sure the drill is going in the 'reverse' direction. If not, the stranded wire will become unwound in the fuel line and be ineffective. Try to penetrate the clog as the drill is spinning the wire. Once the wire will go in as far as you can drill slowly pull the wire out catching the oily goo with a rag. Then you can cut another length of wire 6-10" longer and proceed again. Each time when you pull the wire out catch the goo into a rag. Keep using a longer wire each time until the wire is protruding out the other end. Be sure to put more cleaning fluid into the line each time you pull the wire out. This helps dissolve the goo as you go.

Next, with the wire completely protruding out the other end take pliers and bend a few of the strands of wire out (see image #2) to act as a wire brush. Be sure to bend only a few strands of the wire so the wire won't get into a bind. With the drill spinning the wire very slowly pull the wire out. This allows the bent strands of wire to act as a wire brush inside of the fuel line. Do this several times to completely clean the fuel line. Each time put fresh cleaning fluid into the line, drape several rags over the other end of the fuel line and blow the line out with a high pressure air hose. This should resolve any clogging you might have had.

I have heard you can use a speedo cable to do the same thing.




Steve

My 70 has the S bend in the line to carbs , it narrows from 1/4 to 3/16 there , now calcium it up and its 1/8or smaller, take out the s bend

Ok, dropped the tank after letting it weep black sludge overnight. I have a solid 1" thick layer of sludge in tank. Fuel line is clear, probably block the tank side and fill it with lacquer thinner and soak. Trying some vinegar and baking soda to break up the sludge, been sitting since last night... we'll see. Heading off to the hazmat chemical dump site to lose 6 gallons of the most evil looking...stuff I've ever seen.