Fuel pipe indentification

[Arthur Marshall]

Just had a fuel pipe break on my SR2, and the engineer who fixed it couldn't work out why it was there... it goes via a banjo from the fuel filter back to a junction with the leak off, and basically returns some fuel from the filter back to the tank. There's no indication of it in the manuals that we could find,and he considered just blanking it off if we couldn't fix it (which luckily he did). But can anyone explain why it's there?

[Tony Dunkley]

Just had a fuel pipe break on my SR2, and the engineer who fixed it couldn't work out why it was there... it goes via a banjo from the fuel filter back to a junction with the leak off, and basically returns some fuel from the filter back to the tank. There's no indication of it in the manuals that we could find,and he considered just blanking it off if we couldn't fix it (which luckily he did). But can anyone explain why it's there?

 

It's there to bleed away, and return to the top of the tank, any air which may have found it's way into the (suction) fuel line between the tank and the lift pump, including the lift pump itself. Without it, any air finding it's way in would be forced through the filter and into the injection pumps, resulting in either misfiring and power loss, or the engine stopping completely.

Edited August 12, 2015 by Tony Dunkley

[Iain_S]

Is there a return to the tank?

 

The SR2 in our canal society trip boat has the leak off fed back to a banjo on the filter, with no return to the tank. Not ideal in theory, as the only way out for air is either through the injectors on the bleed screw.

Seems to work, though.

[b0atman]

maybe that's why I have two pipes on my boat to an Isuzu 42 ? must trace them one day.

[Arthur Marshall]

Is there a return to the tank?

 

The SR2 in our canal society trip boat has the leak off fed back to a banjo on the filter, with no return to the tank. Not ideal in theory, as the only way out for air is either through the injectors on the bleed screw.

Seems to work, though.

Yes, the leak off goes to a pipe that wanders back to the tank and then there's an extension to it which goes down to the banjo on the fuel filter. The fuel in there comes out under pressure so that ends up back in the tank too.

 

It's there to bleed away, and return to the top of the tank, any air which may have found it's way into the (suction) fuel line between the tank and the lift pump, including the lift pump itself. Without it, any air finding it's way in would be forced through the filter and into the injection pumps, resulting in either misfiring and power loss, or the engine stopping completely.

Thanks Tony. I'll pass it on to Dick Goble! he doesn't like Lsters much (especially mine these days) - spends most of his time nursing Kelvins.