prefilter additional entry pipe

[vasant]

Hi all,
On my prefilter there are two entries of which one stays unused. I am considering to attach e valve there connected to a hose with a hand pump.
The idea is that this hose can be inserted to a bucket with diesel and help significantly to prime the system when changing filters and maybe even in case the lift pump fails or there is an issue with the diesel tank to have one additional source of diesel that can also be placed well above the engine.
I wonder if this makes sense though because eventually the pipe from the tank to the prefilter would need to be vented as well and if the valve is not goor i would risk maybe air to leak into the system. Anyone who has implemented this or something similar?

 

[coopec]

Do you mean something like this?

How to bleed or prime a Diesel fuel system?

 

[rogerthebodger]

I fitted an outboard bulb between the tank and my sediment pre filter. I also have an electric fuel pump between the pre filter and my primary fuel filter.

I use the primer bulb for bleeding and the electric pump if the engine driven fuel pump between the primary filter and secondary filter.

I have 3 fuel tanks and with a primer bulb sediment pre filter electric pump and primary filter for each tank feeding a 3 position selector valve feeding the engine driven fuel pump and secondary filter

 

[PaulRainbow]

Hi all,
On my prefilter there are two entries of which one stays unused. I am considering to attach e valve there connected to a hose with a hand pump.
The idea is that this hose can be inserted to a bucket with diesel and help significantly to prime the system when changing filters and maybe even in case the lift pump fails or there is an issue with the diesel tank to have one additional source of diesel that can also be placed well above the engine.
I wonder if this makes sense though because eventually the pipe from the tank to the prefilter would need to be vented as well and if the valve is not goor i would risk maybe air to leak into the system. Anyone who has implemented this or something similar?

Not really a good idea. If you fit the primer pump that Roger mentions that makes bleeding much easier. Feeding fuel into the second port from a supply above the main tank would work if their was an issue with the main tank, but not for very long, as the fuel would be returned to the main tank and you supply would run out very quickly.

 

[vasant]

Do you mean something like this?

How to bleed or prime a Diesel fuel system?

yes. but i thought keeping it permanently installed amd isolate it with a ball valve

 

[vasant]

Not really a good idea. If you fit the primer pump that Roger mentions that makes bleeding much easier. Feeding fuel into the second port from a supply above the main tank would work if their was an issue with the main tank, but not for very long, as the fuel would be returned to the main tank and you supply would run out very quickly.

Indeed very valid point. I had the naive impression that as on the filter the arrows shows towards direction IN it cant flow OUT. Anyway the improvement would then to be to connect to the tank inline a 3 way valve to switch between the inputs

 

[rogerthebodger]

a 3 way valve to switch between the inputs

That's what I used to select which of my 3 tanks I wished to use. I in fact connected 2 separate valves together so I could select the tank output to feed the lift pump and the second bank returned the back flow to the same tank.

On my engine the return flow is very little so not so critical but others have a large return flow.

 

[PaulRainbow]

Indeed very valid point. I had the naive impression that as on the filter the arrows shows towards direction IN it cant flow OUT. Anyway the improvement would then to be to connect to the tank inline a 3 way valve to switch between the inputs

You missed my point. If you used a fuel supply as you describe, to put diesel through the 2nd inlet port, the engine will return it to the main tank. Your fuel supply would quickly be transferred to the main tank with many engines. If you use a supply other than the main tank, you should also swap the return to the alternative supply.