15mm Fuel Pipe

[keynsham]

I am currently replacing the fuel pipes on my 350i. The pipe from the swirl pit to the fuel filter is 15mm (or more probably 19/32" as all the other pipes in the area seem to be imperial!)

I can find loads of 16mm pipe but not a sign of any 15mm pipe. I could fit the 16mm pipe and make sure it is clamped up tight with jubilee clip but it would be nice to have the right size.

Does anyone know where I might get fuel pipe of this size?

[Pumpkin123]

I used this stuff, works a treat....
https://www.advancedfluidsolutions.co.uk/58-id-16m...

[phillpot]

16mm / 5/8" will do the job fine.

[Zener]

What fuel filter accepts 16mm or 5/8 or am I missing something?

[keynsham]

I have a replacement fuel pump which has a 15mm inlet and an 8mm outlet. As I want to put the filter before the pump, I need a connector pipe which is 15mm in diameter. The fuel filter has screw in ends so I have a 15mm end as an exit to match the inlet to the pump. My whole system will be weird! There is a 25mm pipe from the tanks into the swirl pot but the outlet of the swirl pot is 12mm. So I go from 12mm on the swirl pot to a 12mm inlet to the filter, but the filter outlet has to be 15mm to match the fuel pump inlet. The fuel pump outlet is 8mm as expected!

If you can understand that then you are doing well!!!

[Zener]

My bad now makes sense now

[Steve_D]

I may be wrong but I don't think putting the filter before the pump is a good idea. By all means a course pre-filter but not the main filter.
Reason being that this type of pump does not suck very well and is also why it is recommended to mount the pump below the normal fuel level in the tank.
Also the reason why most diesels have a lift pump as well as the high pressure pump.

Steve

[keynsham]

That is interesting as I have noticed that the filter is often shown after the pump is diagrams. Maybe I should rethink my pipework??

My swirl pot has been modified (not by me) to remove the filter inside as it was totally blocked. If I have no external filter in front of the pump then there will be no filtering of the fuel before the pump. There does seem to be a filter inside the entrance to the pump though. My external filter would be 12mm from the swirl pot and then 15mm into the pump and 8mm out of the pump so the inlet are is large. Would this really cause a fuel starvation in the pump?

Edited by keynsham on Thursday 14th April 13:31

[Pumpkin123]

I’m guessing somebody removed the filter in the swirl pot and then moved the main filter in front of the pump to compensate.
Got to admit mines slightly different in that I have 16mm pipe from the tank, through swirl pot and pre filter and to the pump and then 8mm to the normal filter and onwards.
Hope that helps….

[keynsham]

Thanks, it does! When I got my car it had no fuel pump or filter or any pipework as it had been removed by the previous owner so I am finding my way around it slowly! It seems odd to have no filter before the pump in my opinion but I see possibly why it is like that.