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Hello im new on here, im 16 i just bought my first car a 1977 el camino classic, ive rebuilt the top end of the motor and some other stuff, im all ready to see if she will fire but i replaced the fuel pump and now gas is shooting out of the over flow nipple on the pump.

After some research i found out i need to connect the overflow line to the nipple so instead of shooting gas on to the ground it will send it back to the tank.
My question is where is the over flow line? I have the main line that runs down the passenger side that feeds gas to the pump. I also have 2 lines that run down the driver side and i think lead to the tank its hard to tell. Can anyone help me out?
 

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One of the lines on the driver's side is likely the brake line that runs to the rear brakes. The return line should be bigger than the 3/16" brake line, like 5/16". And there should be a 1/4" vent line in there, that comes up to the emmision canister on the driver's side of the radiator. It's the 6" diameter black plastic can.
 

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Did you change the fuel pump while rebuilding the top end? If so did the old pump have the return on it? Maybe you got the wrong pump.
 

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What overflow nipple on what pump?????????? are you talking about the vent on top of the carb? on the fuel pump their should only be one inlet from the tank and one outlet to the carb no overflow. The canister only would have gas fumes returning to the tank from the carb vent. If it is pooring out the top vent the carb float is stuck open.
 

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Discussion Starter #6
The older pump had 2 nipples aswell, but wasn't creating enough psi to make it overflow infact the carb wasn't getting enough gas. The reason the overflow nipple is on the pump is to prevent the diaphragm inside the pump from exploding.
 

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Do you have a hard time finding parts for 77's? it seems all parts are for 76 of 78 but never 77
here is some good news, from what ive seen and understand 99% of those 1976 parts u find will fit ur 1977 el camino, most of the 1978 parts wont due to the generation switch.
 

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no problem, our 4th gen cars are soooooo annoying to find parts for.
 

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I can't come up with a good reason why a stock mechanical fuel pump would ever need an external return line. They usually have their own check valves and are internally regulated. My fix would be to buy a pump without the return nipple. I'd cap off the old return line and be done with it.

If someone can explain the reasoning behind the overflow type pumps, I'd appreciate the input.
 

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Hey, guys just got in from looking for the over flow line and i dont think my car has one, but why was gas shooting out of the overflow nipple then? This is the last step in my rebuild and i just wanna hear her purr
 

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You can use a short piece of fuel line and two clamps and a bolt in one end. Be sure you use fuel line and NOT vacuum hose as the fuel will deteriorate the hose.
 

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Hey, guys just got in from looking for the over flow line and i dont think my car has one, but why was gas shooting out of the overflow nipple then? This is the last step in my rebuild and i just wanna hear her purr
I'm going to guess bad or wrong fuel pump. But whatever it is, capping it off is an invitation to a disaster grade barbeque! Those little caps have no re-enforcement in them and when they crack they leak. Not good, especially if it is your garage.

Buy a plain, every day fuel pump which has the fittings in the right place and be done with it. No fuel pump should spew fuel, even into a return line.
 

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If your running a small block your pump should look like this. One line from the tank and one to the carb.
 
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