Time to change out all of the fuel lines...

[e34.535i.sport]

Hey guys, first of all apologies if this is a repetitive problem- I have searched long and hard but a few questions remain unanswered...

Here's the situation- I leave work yesterday to find a puddle of petrol under the car. Not good. I've had problems in the past with a corroded fuel line and had to do a temporoary fix due to lack of funds/time at that point. This time its sprung in a new place, right at the back of the tank where a rubber hose meets the metal line. If i'm honest I'm not sure the rubber hose that is there should be or if its been bodged before?! Anyway I get it home reverse it onto some ramps (scratched the underside of the bumper in the process because its so low) and Syphon pretty much all of the petrol out of it and store it (I put £50 worth in the night before... Typical).

The good news is I'm off work for two weeks now and have got some cash to throw at it so I'm planning to remove the pump etc, disconnect hoses/pipes, drop the tank (PLASTIC), and get a good look at exactly what pipes I need to replace. Questions:

1). Do I definitely need to depressurize the system? If so why?

2). Will I have to disconnect the battery or will I get away without doing it? I didn't for fuel filter/water pump etc.

3). There are two main hard lines what is the better option - getting the steel ones from the dealer or getting some copper ones purpose made? I need to take into account durbility/cost/ease of fitment etc etc. If i go with copper ones I need the dimensions too (i.e how long each section is before bends etc), i've seen them somewhere on this forum before but just can't find them.

4). The two main hard lines (and breathers etc) are horribly corroded at the back end, but from the centre of the car forward they seem fine. Is it best to cut and join there or re-do the whole thing? I only ask because getting the lines in through to the engine bay seems like it could be tricky.

5). Should I replace the fuel pump while I'm there? I don't know its history but don't currently have any problems with it and not sure on the price yet. Looking into it.

If anyone has done this before or can offer any advice or tricks of the trade I'd seriously appreciate it. I need to get this job done I've been procrastinating for long enough... I'm taking the car on a 500 mile trip in August so its gotta be tip-top.

Many thanks in advance.

[e34.535i.sport]

Hey guys thanks for your input, always useful to get a few opinions rather than go with my jusgement (which is usually not too good!).

Been underneath all morning, removed the heat shield #12 and wheel dust guard thing. Looks like there are two hoses that come off the expansion tank that connect to two hard lines. I need these two hard lines, the others seem to be ok. I think on realoem diagram i'm looking at #2 and #3. The hard lines i'm talking about seem to go into the front of the tank and the back of the tank but i can't see until i drop the tank...

Can anyone shed anymore light on this by any chance as i'm not certain its #2 and 3 i'm after?! Here's the diagram...

http://www.realoem.com/bmw/showparts...41&hg=16&fg=05

[whiskychaser]

1). Do I definitely need to depressurize the system? If so why?
Its under 51 psi pressure but a decent rag will soak up what comes out
2). Will I have to disconnect the battery or will I get away without doing it? I didn't for fuel filter/water pump etc.
I wouldnt but if you get a spark with fuel about dont be underneath at the time
3). There are two main hard lines what is the better option - getting the steel ones from the dealer or getting some copper ones purpose made? I need to take into account durbility/cost/ease of fitment etc etc. If i go with copper ones I need the dimensions too (i.e how long each section is before bends etc), i've seen them somewhere on this forum before but just can't find them.
Your local motor shop should be able to make lines up for you. That includes the connections. You just take in the old ones for length/fittings so they can match them
4). The two main hard lines (and breathers etc) are horribly corroded at the back end, but from the centre of the car forward they seem fine. Is it best to cut and join there or re-do the whole thing? I only ask because getting the lines in through to the engine bay seems like it could be tricky.
You need a pipe flaring tool if you cut them. If you do use one, dont forget to put the nut on the pipe first
5). Should I replace the fuel pump while I'm there? I don't know its history but don't currently have any problems with it and not sure on the price yet. Looking into it.
You should have ca. 51 psi pressure on the pump. That goes down to about 44 with the engine running. If you havent got a gauge you can borrow mine
If anyone has done this before or can offer any advice or tricks of the trade I'd seriously appreciate it.
Ask for price at a garage. Laying those lines front to back is a pain. I had my brake lines done. It would have cost £60 for the parts. Garage charged £90 including fitting. Gladly paid the £30 to save me a crappy job

[Rus]

Some answers:
1) You do need to depressurize. The system operates at about 43 psi and you will get a big gasoline shower if you pull off a pressurized line (like one of the main ones going up front) without letting down the pressure. I usually just hook a vacuum pump up to the pressure regulator and open it manually to dump the fuel.
2) I usually disconnect the battery whenever I'm working with the fuel system because of fumes and possible spills. Last thing you need is a spark.
3) No input.
4) Joining hard lines creates extra areas where you can have a leak. Personally, I think I'd replace the entire line just to avoid the complication later.
5) The pump is fairly expensive (~$200) Replacing it is pretty easy, but if your pump works, there's probably no reason to do it. If you want an exact diagnosis, hook up a fuel pressure gauge before the injector rail and see what the pressure is there. Should be 43 psi while running.

Hope this helps.

[e34.535i.sport]

Thanks guys, appreciate the input there.

I've been investigating thoroughly and I need the two pipes that go into the fuel tank (one front and one at the back). They connect to the bottom of the expansion tank. Fortunately it seems the ones to the front will be ok so I'm not going to bother with them... for now.

I don't know if anyone can help me out here, but i've found a bit of a problem. I have the pipes etc i need on order from the dealer and they should be in wednesday. I thought i'd get a head start and remove the fuel pump and sender unit this morning so I was ready to drop the tank on wednesday when I have the parts. However, when I took the egg shaped panel off in the boot and exposed the electrical connector and the in and out hoses... I couldn't find any nuts to undo? Im under the impression there should be six or eight nuts to undo in order to pull out the sender unit after researching this in detail? I've read many threads on this and all pictures look the same... Mine looks different - typical?! Instead of bolts going all the way around I have a big circular plastic 'lid' type item going around the connector and hoses. Anybody else found this before? I attempted to twist it off (as this looked like the only way to remove it) but I didn't want to go primevil on it incase I broke it off.

I'm just charging my phone so I can take a picture or two and post them.

Ideas?

[E34-520iSE]

No problem - your tank sender/pump unit is the same as mine - you just unscrew the large black plastic retaining ring and the sender comes out, and the pump is clipped into the bottom of the tank. Don't just pull the pump out - you have to be careful with those plastic lugs. I replaced my fuel lines 5 years ago with the correct correctly shaped pipes from the dealer, and had no real problems with their install, though I had to bend the pipes a few extra times to get them to fit. All in all though it was an easy enough job, but make sure the system is depressurised first lol!!

Best of luck,

Shaun M

[e34.535i.sport]

Hey thanks Shaun, I find it strange that in all the literature I've read its never been mentioned?!

Here's the pic anyway:

[img=http://img37.picoodle.com/img/img37/4/3/17/f_Image037m_33c37f7.jpg]

Shaun, did you need to take off the in and out pipes before pulling out the sender unit? I think i'll get it on the ramps, pull the fuse and depressurise the system and then get to work removing the pipes etc.

I don't suppose you know how i disconnect the tank from the filler neck do you, or should i just pull?!

Thanks!

[Ferret]

I've depressurised the system, disconnected everything connected to the fuel tank and undone the allen-key bolt that holds the LH support strap on... THe RH one however won't come undone...

I used the correct 6mm allen key initially but the bolt head is quite badly rusted and it just spun when i tryed to turn it. I got a star socket in it and that ended up slipping too (this got the other side out though).

I resorted to getting hold of the head with molegrips and trying to turn it with those but i didn't get far at all with that (nowhere in otherwords).

I see three options now:

1. Put it all back together, book it in a shop and get the bolt drilled, bring it home and continue the fuel line job.

2. Try and drill it out myself (no idea what i'm doing).

3. Continue trying to turn it with the molegrips...

Anybody been in a similar situation? With the bolt being quite accessible i'm tempted to try and get it out myself with my standard drill... but i wouldn't want to wreck the thread on the chassis where it bolts onto.

I can't believe one bolt is stopping me doing this job, its really REALLY annoying.

Drill it is probably your best option, but take your time and be careful, you're working in a dangerous area! If you're not confident, you might as well take the whole job to a trusted garage, as you're gonna get charged an hours labour - you might as well get them to fit the new pipes while they're at it!

[e34.535i.sport]

I've depressurised the system, disconnected everything connected to the fuel tank and undone the allen-key bolt that holds the LH support strap on... THe RH one however won't come undone...

I used the correct 6mm allen key initially but the bolt head is quite badly rusted and it just spun when i tryed to turn it. I got a star socket in it and that ended up slipping too (this got the other side out though).

I resorted to getting hold of the head with molegrips and trying to turn it with those but i didn't get far at all with that (nowhere in otherwords).

I see three options now:

1. Put it all back together, book it in a shop and get the bolt drilled, bring it home and continue the fuel line job.

2. Try and drill it out myself (no idea what i'm doing).

3. Continue trying to turn it with the molegrips...

Anybody been in a similar situation? With the bolt being quite accessible i'm tempted to try and get it out myself with my standard drill... but i wouldn't want to wreck the thread on the chassis where it bolts onto.

I can't believe one bolt is stopping me doing this job, its really REALLY annoying.

[Barney Paull-Edwards]

Ha ha ha... This is the first and only car i've worked on really but been fairly lucky in the jobs i've done! The captain and I work on each others cars he has a 1992 e36 320i and we recently done a bit of work on a 1999 VW golf (only brake work). The front end of my car is in pretty good nick but the back end is rusted up a fair bit... Fine from outside but when you get underneath its a different story.

Yes standard strap and bolt with the 'nut' welded to the car. I managed to hammer a 1/4" allen key into the bolt head today and when I turned it I just snapped the allen key... Marvelous. I'm planning on drilling it tomorrow because I've had enough of the little f*cker. Went to a shop today and priced up them drilling it... between £30 and £60 so I'm gonna have a bash myself first as I hate paying labour for something I can do (no offence to our mechanic friends). Never done it before but I have a plan...

I'm going to drill through the bolt and get rid of it, then put a new nut and bolt through it... There should be room to get a nut on top i reckon.

I cant wait to get this bolt out, I'm going to dance on it's grave I really am.

There is room for a nut and bolt job! If all else fails cut the strap with an angle-grinder, remove the tank, change the pipes, remove the strap and either weld it together or replace it and carry on!