Fuel line removal question

[gr_diver]

Hello friends!

I am thinking of replacing my fuel pump, to solve a hard cold-start issue I have, due to low fuel level in the carburetor. My dad had the same issue about 15 years ago, and it was the fuel pump....

If I remove the line from the pump's outlet port, would gravity drain the tank like when removing the pump's inlet line? Or are they internally isolated in the pump?

Thank you!

[tekenaar]

Originally Posted by gr_diver Hello friends! I am thinking of replacing my fuel pump, to solve a hard cold-start issue I have, due to low fuel level in the carburetor. My dad had the same issue about 15 years ago, and it was the fuel pump.... If I remove the line from the pump's outlet port, would gravity drain the tank like when removing the pump's inlet line? Or are they internally isolated in the pump? Thank you!

Mechanical fuel pumps have two separate, valve controlled cavities, an inlet (from gas tank, gravity fed) and outlet (to carb, pressurized by pump action), and fuel is isolated between inlet and outlet lines by both valves in pump, not just one.

[Dan-MI]

If you disconnect the fuel line from the tank to the pump, it will drain the gas out. What I did was shove a bolt in the rubber gas line and then clamp it down. That allows you to leave the line just sitting there and not leaking gas all over.

[gr_diver]

Thank you for your replies!

I do not like clamping flexible hoses, because old ones can break, and new ones can be harmed and then fail prematurely. Thus I am thinking of leaving the inlet connected to the old pump while I install the new one, then with a quick motion remove the line from the old inlet and hook it up to the new pump's inlet...

This will method also makes the line leak one time during swapping, instead of two times (one while removal and plugging, and second while de-plugging and reinstalling).

Can be done then...


Thanks once again!

[baronbors]

Originally Posted by gr_diver Thank you for your replies! I do not like clamping flexible hoses, because old ones can break, and new ones can be harmed and then fail prematurely. Thus I am thinking of leaving the inlet connected to the old pump while I install the new one, then with a quick motion remove the line from the old inlet and hook it up to the new pump's inlet... This will method also makes the line leak one time during swapping, instead of two times (one while removal and plugging, and second while de-plugging and reinstalling). Can be done then... Thanks once again!

Thats how I did mine and it worked great- just have a drip pan under the pump and get every thing you need ready for the quick swap out.

[tekenaar]

Originally Posted by gr_diver Thank you for your replies! I do not like clamping flexible hoses, because old ones can break, and new ones can be harmed and then fail prematurely. Thus I am thinking of leaving the inlet connected to the old pump while I install the new one, then with a quick motion remove the line from the old inlet and hook it up to the new pump's inlet... This will method also makes the line leak one time during swapping, instead of two times (one while removal and plugging, and second while de-plugging and reinstalling). Can be done then... Thanks once again! Originally Posted by baronbors Thats how I did mine and it worked great- just have a drip pan under the pump and get every thing you need ready for the quick swap out.

. . . OR, you could remove inlet hose and stick a stubby phillips screwdriver in the hose end while changing pumps . . . the way I usually do it!

[Sparky73]

I ordered a new fuel pump, and this is probably a stupid question, but there is an arrow by one of the lines. Does this indicate the fuel flow? It is pointed inwards, as in.. that would be the inlet. I assume this is correct.. but it is the opposite of how it was hooked up before, when there was also an electric pump feeding the carb.

[namba209]

I would think that would be flow direction. One way to check it out is to hook up short pieces of hose to each fitting, and stick both ends into a fuel can with fuel in it, hook up a power source, then pull one hose out, but is aimed at the opening, and see if fuel comes out or nothing comes out. That will tell you for sure which is inlet and which is outlet. HTH.