Replacing 540i fuel pipes

[euaniebabs]

Hi Guys,

One of the vent pipes on my 540 split at the weekend having just filled it up. I managed to cut the offending part of pipe out and put in a rubber hose but want to do the fix properly. This is the 2nd time I have sprung a leak! Fortunately I managed to save the tank of fuel plugging the hole with a finger! Fuel comes out fast though as you cut through the pipe - sources of ignition best avoided...

Does anybody have experience fitting copper fuel lines? They last longer than steel and are easier to bend to fit.

Any ideas what diameters and lengths I need to do all of the tank feed/vent lines as well as the main engine feed and return pipes?

My plan is to drop the tank out and replace everything looking corroded.

Many thanks

Euan

[leicesterboy15]

I have this problem at the moment so will watch this closely. Can you paint the lines with rust inhibiting paint or do the lines need to 'flex' slightly?

[euaniebabs]

In my experience painting fuel and brake lines only holds off the tin worm for a little longer. I have used rust remover and hammerite in the past. Once the corrosion has taken hold however, it is virtually impossible to stop - cleaning the pipes back to bare metal, cleaning and painting is not practical around all of the bends, clips and shields. The pipes are usually epoxy coated when new - this is great protection for about 10 years but after that things get steadily worse - particularly with our salty roads!

My lines are still of good thickness in section (i had to cut a section out), but there are obviously local thin spots which coupled with vibration, bending and temperature variation lead to cracks.

Some nice copper lines with new rubber hoses and clips at the ends should solve the problem and will be far easier to fit than the preformed steel items :)

Euan

[yaofeng]

BMW sells prebent fuel lines at very reasonable prices. You should get them from your dealer. Although if you do not drop the rear subframe you need to cut the line to make connections. I did my 540 using stainless steel tubings. They are 5/16" or 8 mm.