Injector rubber hoses

[DIESELNATION]

What is the purpose of the rubber injector hoses that go from injector to injector? Should there be fuel flowing through them?

DieselNation

[psfred]

Actually, some fuel always leaks around the nozzle on a diesel. The rubber lines (use the MB stuff, I've never found anything else that works) return the leakage to the tank.

The overflow from the IP and fuel filter use the same return line, though, so if they leak, you will dump quite a bit of fuel even if the leakage from the nozzles is minimal.

Peter

[DIESELNATION]

Can you tell how good of shape an injector is in by how much it leaks through the rubber hose?

DN

[DIESELNATION]

No, I am just curious if the amount of flow from the injector through the hose is an indication of the condition of the injector.

DN

Not sure if there is any way to determine injector health by the amount of fuel flowing through them. I used that translucent yellow 2 stroke fuel line (weedeater stuff) to replace the leaking fuel lines on the 240D. There are still air pockets in these lines. Kinda neat to be able to see the fuel through them.

[MarkM]

The rubber bypass lines carry much, much, much more fuel than is actually injected...this just insures that fuel supply at the injector is always more than adequate....you cannot tell anything about how much is leaking past the injector based on how much is in bypass line. That would be like using fuel mileage to see if you have any fuel leaks!!

[P.E.Haiges]

I've been told that the injectors use the excess fuel to lubricate the moving parts inside the injectors. Not sure though because there are somemakes of injectors do not have excess fuel lines.

P E H

[MarkM]

Probably true since the fuel functions to lubricate internal working parts of the injection pump...this is why I religiously add some 2-stroke engine oil to fuel tank every time I get fuel...this ensures adequate lubrication of injection pump in light of low sulfur/low lubricity fuel....will have the same benefits for injectors.