Draining Gas from Cars

When you turn the key to the on position,
gas pump comes on to get fuel line to the correct pressure
if you have the line cut then it will never reach that pressure and SHOULD continue to run until you drain the tank

Originally Posted by JohnC4X4

When you turn the key to the on position,
gas pump comes on to get fuel line to the correct pressure
if you have the line cut then it will never reach that pressure and SHOULD continue to run until you drain the tank

There SHOULD be a safety system that prevents the fuel pump from working if the engine is not running. Lets say you get in an accident and the fuel line brakes, if the pump does not shut off you now you have fuel spraying causing a fire hazard.

Originally Posted by Immulmen

There SHOULD be a safety system that prevents the fuel pump from working if the engine is not running. Lets say you get in an accident and the fuel line brakes, if the pump does not shut off you now you have fuel spraying causing a fire hazard.

There is. It's called an inertia switch, and it's basically a breaker on your fuel pump circuit. It's "tripped" by a hard impact or rollover. It's reset by pushing down the button that pops up when it's tripped. They're usually mounted inside the trunk on the side, or under the dash at the floor or on a kick panel. If you have a car that's been in an accident and won't start, that's sometimes why.

The yard I haul cars to wants them drained with a good sized hole, but they can still be in the car. They shred the cars, tanks and all. Propane tanks are totally forbidden, not even the little camping ones. Gas usually won't cause an explosion in the shredder, only a fire (which is bad enough). Unless it's quite a bit more gas than a holed tank would hold and was missed by staff. Propane tanks apparently will explode though. When cars come in, the loader operator unloading them flips them on the side to see if the tank is out or at least holed. If not, he'll punch a hole with a fork to drain it.

I usually drop my fuel tanks entirely and then drain them once they're out with a siphon pump. Late '80's Ford pickups had a frame mounted fuel pump (LH frame rail right below/behind the engine) that makes a great siphon pump, and should be cheap and easy to find for most scrappers. This way I don't have to deal with any spills, or contaminating any useable fuel. If it's a tank that's a pita to remove, I'll punch a hole if it's steel or drill it if it's plastic to drain it. I won't use a sawzall on a metal tank, too many sparks. If you don't think they spark, try using one in the dark and you'll see all the sparks coming off the motor and the blade. In my own personal experience, I've only seen or heard of one fuel tank fire caused that way, and it was to a scrapper I know who was using a sawzall on a steel Chev truck tank. Seeing the shriveled skin on his hands and arms just reinforces to me that I'm doing it right.

Originally Posted by zito

There is. It's called an inertia switch, and it's basically a breaker on your fuel pump circuit. It's "tripped" by a hard impact or rollover. It's reset by pushing down the button that pops up when it's tripped. They're usually mounted inside the trunk on the side, or under the dash at the floor or on a kick panel. If you have a car that's been in an accident and won't start, that's sometimes why.

The yard I haul cars to wants them drained with a good sized hole, but they can still be in the car. They shred the cars, tanks and all. Propane tanks are totally forbidden, not even the little camping ones. Gas usually won't cause an explosion in the shredder, only a fire (which is bad enough). Unless it's quite a bit more gas than a holed tank would hold and was missed by staff. Propane tanks apparently will explode though. When cars come in, the loader operator unloading them flips them on the side to see if the tank is out or at least holed. If not, he'll punch a hole with a fork to drain it.

I usually drop my fuel tanks entirely and then drain them once they're out with a siphon pump. Late '80's Ford pickups had a frame mounted fuel pump (LH frame rail right below/behind the engine) that makes a great siphon pump, and should be cheap and easy to find for most scrappers. This way I don't have to deal with any spills, or contaminating any useable fuel. If it's a tank that's a pita to remove, I'll punch a hole if it's steel or drill it if it's plastic to drain it. I won't use a sawzall on a metal tank, too many sparks. If you don't think they spark, try using one in the dark and you'll see all the sparks coming off the motor and the blade. In my own personal experience, I've only seen or heard of one fuel tank fire caused that way, and it was to a scrapper I know who was using a sawzall on a steel Chev truck tank. Seeing the shriveled skin on his hands and arms just reinforces to me that I'm doing it right.

I know about the inertia switch. What I am saying is I have not had a car that can run and you disconnect the fuel line and the pump will stay running with the key on without the engine running. So disconnect the gas line and turn the key on. The pump will turn on and go off if the engine is not running even if the inertia switch has not been tripped.