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Discussion Starter #1
Finished replacing my fuel filter but noticed that the fuel lines on the bottom of the fuel pump had some worn spots and needed to be replaced. These are the lines that run from the base of the fuel pump to the quick disconnects. The lines have pre-formed bends in them.

Do I need to order fuel lines from BMW or will other fuels lines work? Regular fuel line seems very flexible as compared to the existing lines. BTW this is on a 2005 LT.
 

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Wrencher Extraordinaire
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You may be able to get by with some regular FI tubing but it will kink. I have used stainless steel springs in side tubing before to prevent the kink.
 

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I replaced both of my aged hoses that do the crossover from the QD's to the Fuel Rail with high quality FI hoses, making sure that there was plenty of room for them to make as gentle a curve as possible, and they have been fine for months now. Just an FYI.

John
 

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AlaskaFish said:
I replaced both of my aged hoses that do the crossover from the QD's to the Fuel Rail with high quality FI hoses, making sure that there was plenty of room for them to make as gentle a curve as possible, and they have been fine for months now. Just an FYI.

John
Regular FI hose and screw type FI hose clamps worked fine for me. No problems at all.
 

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jzeiler said:
You may be able to get by with some regular FI tubing but it will kink. I have used stainless steel springs in side tubing before to prevent the kink.
John... Can you give a little more info on using springs as you describe herein? A pic or two will help my feeble mind if you have any to share.

When I do the clutch, am replacing springs, QDs, and was thinking about fuel lines. My '05 was originally from Las Vegas and now lives in Texas. Thinking after 7 years of Hades hot it may be time to change lines. Your thoughts?
 

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You Know If It Was Me......I'd go ahead and get the pre formed rubber fuel injection lines from BMW.

Fuel Injection hose is expensive at the Auto store anyway. And those lines make a 180 Degree turn, (pretty tight for a hose),

Max bmw shows them for around sixteen bucks each. (I like to use the Squeezum clamps).
 

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I used the spring inside the hose idea when I replaced the hoses on my fuel filter inside the tank. For all the hassle I went through I'd spring for the BMW hoses if I had to do it again...... :)
 

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deputy5211 said:
John... Can you give a little more info on using springs as you describe herein? A pic or two will help my feeble mind if you have any to share.

When I do the clutch, am replacing springs, QDs, and was thinking about fuel lines. My '05 was originally from Las Vegas and now lives in Texas. Thinking after 7 years of Hades hot it may be time to change lines. Your thoughts?
Think of the spring as a stint in an artery, it is a structure that keeps the artery from collapsing. That is what the spring does. Outside diameter of the spring should be such that it slides into the hose and prevents it from kinking if you have a tight bend.

I am in hot conditions here in AL as well and my 8 year old fuel lines still look pretty good.
 

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Discussion Starter #10
Thanks everyone for the help. I don't think I would of thought about inserting a spring inside the fuel line. I went ahead and ordered pre-formed hoses as they weren't very expensive, but I'll keep the spring idea in the back of my mind. Of course sometimes I can't even remember why I got out of the chair (senior moments).
 

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jzeiler said:
Think of the spring as a stint in an artery, it is a structure that keeps the artery from collapsing. That is what the spring does. Outside diameter of the spring should be such that it slides into the hose and prevents it from kinking if you have a tight bend.

I am in hot conditions here in AL as well and my 8 year old fuel lines still look pretty good.
Thank you, John. Your stent analogy was spot on and cleared it up for me.
 

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I've put springs on the outside of fuel lines for many years...

Then Gates (one of my very favorite companies in the entire world) copied my idea :D and did me one better: The Uni Coil.

Gates Unicoil

It's simply a non springy coil of wire with a maleable "stay". Very clever and very useful. I recently had to replace the hose from the power steering reservoir to the pump on my '88 Cheby truck. Needless to say the very short and thick pre-formed "S" shaped hose is no longer available. This was my only easy solution - and while it set me back $10.00 :eek: - it works great.

(I too would buy the OEM hoses for the Brick and be done with it...) ;)

While John's idea certainly works in my opinion it will also restrict flow since it effectively narrows the internal diameter significantly. Most likely not enough to hamper delivery under normal throttle, but under WOT I would not be surprised if there is a demand issue. I would do it on a carbureted engine - but never with FI.

I HATE running lean - but the Moronics would probably detect it and adjust accordingly. :think:
 

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RonKMiller said:
I've put springs on the outside of fuel lines for many years...



While John's idea certainly works in my opinion it will also restrict flow since it effectively narrows the internal diameter significantly.
:think:
There you go Ron always thinking OUTSIDE the box(hose). I"ll have to try that next time

The spring is no more an impediment to flow than the fitting that inserts into the hose. Same size.
 

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jzeiler said:
There you go Ron always thinking OUTSIDE the box(hose). I"ll have to try that next time

The spring is no more an impediment to flow than the fitting that inserts into the hose. Same size.
Ahh, well not exactly - you need to take into account the viscous losses and turbulence along the length of the spring too... not sure how they add up but my bet is that they are significant and most likely increase geometrically as the pressure rises.

Bernoulli's ways are many and amazing. :D



and if anyone is so inclined they might be able to figure out a rough estimate off how all this works with this handy calculator:

Pressure

Me? I have a hard time balancing my check book! ;) But ya' know what, if it works internally without grenading the engine, Kewl! :thumb:
 
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