Fuel tank flush procedure

[c3ntral_scrutiniz3r]

Question:
What is the recommended procedure for draining fuel from the tank? I have just bought a 70 RR w/ non original 440 and auto (was 383/ 3sp manual) that has sat for 2 yrs. John Cope (CRT) did the trans and says the car was running great in his shop but 2 yrs sitting probably has bad fuel.

Thanks for advice
Jon
Stafford VA

 

[5.7 hemi]

Drop the tank, or stick a hose in it and siphon the "varnish" out.

 

[craigp]

Drop the tank and pull the sending unit and siphon out the old fuel. I have a 78 Magnum, only read 1/4 of a tank but it actually was more than 3/4 full. the old gas had sat for a good while and gummed up the sending unit and the filter sock was cracked and doing nothing. Take the tank out and inspect everything before you go much farther, it will be well worth it. I ended up removing the old fuel sock, rebuilt the sending unit, blew out the fuel and vent lines, put in a new fuel pump and the car runs like a champ. While the tank is down inspect any rubber fuel and vent lines and just replace with new while you're at it.

 

[c3ntral_scrutiniz3r]

70 RR fuel tank drain follow up

Thanks for the input/advise. First, I added half a can of seafoam to fuel tank, and at that point, the car started up and ran. Idling in the driveway, all seemed well, so I drove it around the block. I noticed oil pressure looked good, but some oil leak near dipstick. I ran it around the block again and got into the motor a bit, and noticed on deceleration that there was a LOT of racket - clattering metal sounds. Made me nervous so I eased the car back into the driveway. The car has a 440 - internals unknown but thought to be near stock- and trans is the CRT street performance 727 w/ reverse manual valve body.

Back in the driveway I noticed that the radiator was overflowing water - car had only been running 10 minutes - and noticed fuel leaking out by gas tank. Since I was originally suspecting bad fuel as a cause of the motor shutting off after starting, I decided to drain out the fuel as mentioned earlier. I pulled a hose from the front of the fuel tank, and let drain into 5 gallon buckets. I filled two of them, and the fuel looked dirty. Like piss after an all nighter at the heavy metal show.

This evening, Im going to r/r the 3/8" fuel hose at the tank which was leaking after yesterday's hard run around the block, and pour in a few gallons of fresh 93 octane fuel. But, Im a little concerned about the deceleration noise. It sounded like more than lifters. Oil level looks good. Motor starts up and sounds good, but if I rev it up it clatters in decel. I should note, that while under the car when this was discovered, I noticed that one of the mufflers is torn apart - fist size hole.

Any thoughts on this?

 

[craigp]

Check and see if you have any of the heat shields on the exhaust manifolds still on the car. I have one where the ears have rusted away where it bolts to the manifold. It rattles. See if the engine will make the noise while in the driveway, rev it up and then let off the gas and see if you can hear or see anything.

Muffler, who knows, someone probably ran over something or it just rotted through from moisture laying in it.

When you're replacing rubber, replace any vent lines too. I also replaced the rubber donut that the filler neck slides into on the tank. Mine was dry and cracked and could let gas leak out under hard acceleration, definately would let vapors leak out. All rubber fuel & vent hoses should be replaced, it just saves headaches later.