Strange valve

[4x4_76]

My brother was welding new steel on his 'Burbans fenderwell,and he found small drain valve or something like that on the right frame rail.It's located right in front of the fuel tank,and it sticks out in the midlle of the frame.It has small rubber plug,and when it was removed,diesel fuel came from there.We were wondering that what purpose it has?Draining the fuel tank?

I'm too lazy to stick shift,that's why I prefer autotranny.

 

[6.2 man]

That valve is used to drain water out of the tank .....diesel is heavier than water and it floats to the top and siphons off the water

 

[4x4_76]

Ok.For a monent I thought that someone could stole all your fuel if knows that valve.So it takes only from the top of the tank...half gallon or so?

I'm too lazy to stick shift,that's why I prefer autotranny.

 

[NewK5Guy]

Correction(but I coule be wrong): Water is heavier than diesel fuel. The water settles to the bottom of the tank. Excess water can be pushed out through that water drain hose by the weight of the fuel on top. If only diesel came out, then you are in good shape. The tank water drain hose is a last resort to fuel problems where too much water has been introduced into the system. The fuel pickup filters for the diesel tanks are even designed to filter out water to leave it in the tank. No water means you've been using good fuel.

 

[tshiko]

I though that it was an intake valve, not a drain ... and it could be used with an air compressor to push the fuel through the line when you get air in the fuel line (say after a filter change).

The drain valves are usually at the bottom of the primary fuel filter located on the firewall.

 

[4x4_76]

Yep,you're right,water is heavier.I had to check it on my chemistry book.

I'm too lazy to stick shift,that's why I prefer autotranny.

 

[6.2 man]

I stand corrected ! I did forget water is heavier than diesel .