MEP-803a: why different fuel lines?

[m32825]

Preparing to replace my fuel lines and I'm wondering why there are hard lines and soft lines for the non-ip part of the circuit? If soft line is good enough for part of the run, why isn't it good enough for all of it?

-- Carl

 

[jamawieb]

The hard lines go from the injector pumps to injectors, they have to handle 1300-1800psi. The soft hoses are return lines which only have 6-7psi. I hope I understand your question.

 

[m32825]

I understand the hard line between ip and injector, but mine has hard line from fuel pump over to the fuel filters as well. It would be easier to run 1/4" hose, why is that part done with a hard line?

-- Carl

 

[Bmxenbrett]

You will never replace the hard line. Soft hose you will have to replace due to age.

 

[jamawieb]

I understand the hard line between ip and injector, but mine has hard line from fuel pump over to the fuel filters as well. It would be easier to run 1/4" hose, why is that part done with a hard line?

-- Carl

My assumption would be that the hard line will not fray due to vibration being next to the housing and then there is no added weight on the water separator housing. The housing is aluminum and having a fuel hose hanging down, with consist vibration could cause problems

 

[m32825]

Thanks guys, good explanations!

-- Carl