What is the Point of the Sedimenter on the Return Side?

[Iwburch]

Hi all,

As I clean out the blocked in-line filter in the banjo fitting under the exchange pump for the second time in a week... I'm scratching my head as to why the Sedimenter is on the return side for a Perentie. Surely by this point the fuel has been well filtered.

Any insights?

Cheers,

Ian

[303Gunner]

It shouldn't be! It should be located between the tank and lift pump. Are you sure you haven't confused the lines?

Of the two lines going to the tank, the forward one is the pickup and the rear one is the return (and also the fuel gauge).

[Iwburch]

Interesting...

What you describe would make sense but is not how this vehicle came (direct from the Frontline auction), nor how it is shown in the EMEI. I blew compressed air through the line at the sender 'pickup' (disconnected from the supply side of the lift pump) - the rear connection on the top of the fuel tank - and verified this connects directly to the lift pump under the manual primer.

Is it possible that there is an error in the EMEI and my vehicle was uniquely serviced by a RAEME vehicle mechanic IAW the EMEI, but contrary to common sense?

[dodgeguy1942]

Is there joiners in the two lines near pump where they could be crossed over?

[Iwburch]

Yeah it's easy enough to do. Both lines connect via flexible pipe at the same point 10cm back from the lift pump.

However Figure 27 and 28 (plus the associated paragraphs) in the EMEI for Unit Repair, correlate with my current physical setup as found... so whilst it makes logical sense to flip them and introduce the Sedimenter on the supply side... I guess I want to verify that the EMEI is wrong and that my vehicle as purchased from Army was also wrong (I'm not a fan of coincidence) 

Cheers,

Ian

[303Gunner]

Of the two lines going to the tank, the forward one is the pickup and the rear one is the return (and also the fuel gauge).

Interesting...

What you describe would make sense but is not how this vehicle came (direct from the Frontline auction), nor how it is shown in the EMEI. I blew compressed air through the line at the sender 'pickup' (disconnected from the supply side of the lift pump) - the rear connection on the top of the fuel tank - and verified this connects directly to the lift pump under the manual primer.

Is it possible that there is an error in the EMEI and my vehicle was uniquely serviced by a RAEME vehicle mechanic IAW the EMEI, but contrary to common sense?

I had a look at the 4x4 G103 Unit Repair EMEI, and it's true that is how it's shown in fig 27 and Fig 28! Surely they couldn't have repeated the error twice? Bizarre! I'm not sure if that's how they intend it to be piped, but on the 6x6 it IS plumbed the sensible way around, both in the book (note the directional arrows along the sender and return lines), and on the vehicle.

[Iwburch]

Thanks for the 6x6 insight. Will flip the plumbing and hopefully stop my inline filter being blocked with sludge. A fuel tank clean is obviously required.

Cheers,

Ian

[alvin]

Very interesting read.
I know nothing about this yet as I've only had my Perentie a short while, but will be doing a major service and clean up shortly.

I've had a good read of all the comments and two things stand out to me.

1. It would be interesting to see (or possibly hear) where the supply feed was actually coming from inside the tank. Is there any way of checking that out by lifting or undoing an entry point to the tank and having a look? Because would (or does) the supply favour the rear of the tank with fuel if climbing with low fuel in the tank, or does it just have different pickup points in different spots inside the tank, either way, the supply would surly be very differently configured than the return and a physical inspection would quickly show which one it was?

and
2. If it's meant to be configured just like the 6x6 diagram shows, then you may be the unfortunate recipient of a mechanic who's just followed the diagram from the book at some stage and the book (for the 4x4) is in fact incorrectly drawn, which can happen and then the mistake just gets perpetuated.

Your findings will be very interesting indeed.

And pardon my ignorance, but just looking at the two diagrams, are we looking at the front of the tank? If so that puts the supply to the motor on the front, have I got that right or is the tank the other way round?
Alvin