1995 540i fuel line diameter

[vroomZOOM]

Hello
I am repairing my 540i after it sat over grass for two years and a lot of things have to be replaced, including the brake and fuel lines. the lines in the car are pretty bad, maybe they are even the original steel ones. Because I have limited time in the shop, I would save time if I could find out the diameter and length of the lines versus going to the trouble of taking them apart. does anyone know what kind of tubing is used in the 540i and how long is it?

Thanks

[shogun]

Use your VIN and then check on www.realoem.com and buy the fuel lines by the meter. Usually it is mentioned like Fuel hose 6X11MM , Fuel hose 8X13MM , length you can measure on the car.

[ross1]

Fuel line rubber hose is 8mm I.D. so the pipe ought to be 8mm also.

[vroomZOOM]

can I put rubber hose and is it better or should I stay with the steel lines? people say steel lines will outlast the car

[shogun]

no need to replace steel lines, leave the steel lines where they are, just replace the fuel hoses, fuel hoses PLUS vacuum hoses. Plus probably some of the hydraulic hoses.

[vroomZOOM]

the fuel and brake lines are made of steel and have rusted away, and I can't find what diameter they are

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the rubber part to the charcoal canister and to the steel tubing is OK

[vroomZOOM]

hmmm... I have 3 fatter lines, two of them the diagram has verified as fuel, one on the left, and one on the right, and 2 brake lines on the left side. there is also some kind of line that looks in diameter like the fuel lines but it is not in the diagrams. I looked on the website mentioned above and it doesn't seem to have the specs for the lines. sorry, forgot to mention that these lines are on the underside of the car running to and from the engine compartement.

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sorry... also forgot to mention that by lines I meant the steel tubing

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will try post some pictures on monday, though I will have to take it apart by then

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serial # is GF32788

[shogun]

Based on the VIN here some links
http://www.realoem.com/bmw/enUS/part...BMW-540i&mg=13
http://www.realoem.com/bmw/enUS/part...BMW-540i&mg=16
brakes http://www.realoem.com/bmw/enUS/part...BMW-540i&mg=34
power steering, ASC+T http://www.realoem.com/bmw/enUS/part...BMW-540i&mg=32
in case the car has rear self leveliing shocks, see here for the lines http://www.realoem.com/bmw/enUS/part...BMW-540i&mg=33

[vroomZOOM]

hmmm... how could I distinguish self leveling shocks? they look kinda low,but is that normal with the engine not running?

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it says fuel pipe on the website, but no specs or anything

[shogun]

Self levelling shocks have a hydraulic hose connection at the bottom and on the rear axle there is a regulating valve which lowers or raises the rear. These are SLS/LAD shocks http://www.bimmerboard.com/forums/posts/1261417/
Here is the workshop manual https://www.bmwtechinfo.com/repair/main/

"t says fuel pipe on the website, but no specs or anything">>>which one, post the link to realoem where you found it

[vroomZOOM]

http://www.realoem.com/bmw/enUS/show...diagId=16_0186

number 2 and 3 are the pipes that are shot

[shogun]

These you can buy ready made from the dealer or other online shops, for example here with pics, check with realoem which one is needed
https://www.ecstuning.com/b-genuine-...e/16121182171/
https://www.ecstuning.com/b-genuine-...e/16121182418/

[ross1]

can I put rubber hose and is it better or should I stay with the steel lines? people say steel lines will outlast the car

Not a good idea to use rubber hose under the car. Clearly steel lines don't outlast the car.
My advice is to buy a spool of copper/nickel tubing which is easier to bend, flare and will outlast the car, and a flaring tool to make your own lines. The place where they usually rot is near the rear sub-frame, replacing them with the pre-bent factory parts(without mangling them anyway)requires you to drop the sub-frame and fuel tank, a big job.
You can patch in sections, just be sure to use flare unions and not compression fittings.

[vroomZOOM]

This is what I am trying to figure out... I want to buy spool of that copper/nickel tubing but I am trying to fine out the diameter so I know which size to buy

thanks

[ross1]

I think this was answered in post #3

[vroomZOOM]

what about the brake lines that run there? they are thinner

[Layne]

Every BMW brake line I've ever seen was 3/16" (probably actually 5mm originally). You can buy generic un-bent lines with the ends already on them (M10x1 bubble flare). It's not that easy to make your own bubble flares and the tool is expensive. Realoem will probably tell you what length of un-bent line has superseded the original pre-bent line, or perhaps some of the pre-bent ones are still available. You can only find un-bent lines up to 5ft locally, but you can find longer ones in coils online.

[ross1]

Every BMW brake line I've ever seen was 3/16" (probably actually 5mm originally). You can buy generic un-bent lines with the ends already on them (M10x1 bubble flare). It's not that easy to make your own bubble flares and the tool is expensive. Realoem will probably tell you what length of un-bent line has superseded the original pre-bent line, or perhaps some of the pre-bent ones are still available. You can only find un-bent lines up to 5ft locally, but you can find longer ones in coils online.

I used to think that way too, in fact nearly bought a hydraulic tool. The first step of an inverted flare has served me as a satisfactory bubble flare, at least with copper/nickel tube.

[vroomZOOM]

well, im back after a while to work on this car. people say its junk but I swear its going to be valuable someday and I dont want a zf transmission going to the scrapyard, so well, I work on this car. I must have been really pissed about the lines rotting out when i went to buy new tubing - oops bought stainless steel fuel line. yes its meant to be bent but its harder to bend. I have a full shop worth of tools, like benders and bubble flaring tools and lathes and etc but my question is, in practice, how many things do I have to remove to be able to properly bend and install the fuel line? Im just wondering if any of you have done it and if it necessitates the removal of the axle or something. also, there are clips under the car that hold the lines. well, every single screw is rusted tight - had to use the drill treatment. now there is a stub with the remainder of the screw sticking out. tried the vice grips to remove it and POP!the whole stud with the thread in it and screw went in one piece, leaving a round spot on the body - now what do I do? do I weld a stud on or is there a solution that someone made up who has been in this situation before? one last curiosity question - from each wheel there is a white fairly thick plastic tube - whats that for? thanks

[vroomZOOM]

Not a good idea to use rubber hose under the car. Clearly steel lines don't outlast the car.
My advice is to buy a spool of copper/nickel tubing which is easier to bend, flare and will outlast the car, and a flaring tool to make your own lines. The place where they usually rot is near the rear sub-frame, replacing them with the pre-bent factory parts(without mangling them anyway)requires you to drop the sub-frame and fuel tank, a big job.
You can patch in sections, just be sure to use flare unions and not compression fittings.

luckily I dont have to drop the tank, there is rubber hose going to the side where the filters are, and from there it is metal. now the guy at the parts store says FLARE UNIONS should NEVER be used on a car?I agree with you and not that guy! If I have to drop the sub frame I will, but yes its going to be one heck of a job, and im limited on time in the shop

[ross1]

luckily I dont have to drop the tank, there is rubber hose going to the side where the filters are, and from there it is metal. now the guy at the parts store says FLARE UNIONS should NEVER be used on a car?I agree with you and not that guy! If I have to drop the sub frame I will, but yes its going to be one heck of a job, and im limited on time in the shop

So, what does this knuckle dragging counterman suggest?
Perhaps if he had ever serviced a car, rather than tapping away at an electronic parts data base and chatting up amateur wrenchers, he might have noticed that virtually every hard line connection from the factory on essentially every car made uses flare connections. Moron!

[vroomZOOM]

ya, duh

[moroza]

8mm

I just replaced my fuel hard lines. The subframe "has" to come out but 1. it may be possible to wiggle the lines around it, and 2. if you're making your own, you could make them in two sections joined by a short flex line for easier assembly. Also, you might be able to just lower the subframe without removing it. The fuel tank does not need to come out regardless.

Those screws are a pain, eh! Soak in PB Blaster overnight and hope for the best, but I still broke two. If you actually broke a hole in the body, you need to close it somehow. I suggest removing the carpet, sanding/painting the bare metal at the hole (enlarge as needed), then installing this stack: M4x0.8x30mm (give or take on the length) stainless steel bolt, big washer, RTV, another big washer with RTV, a nut with threadlocker, then the plastic line bracket, a smaller washer, and a nut with anti-seize.

[vroomZOOM]

ok, so now I have the new line in and im trying to get fuel pressure at the engine but there is none. will the pump turn on if I turn the ignition to on without the engine running or do I have to crank the motor to get fuel pressure

[vroomZOOM]

well now i have determinted that there is no power going to the fuel pump fuse from the electronics box, even when I bypass the relay. the diagram says that there is some cooling fan there that is connected in there. does anyone know where the junction is and how to get at it?