Author Topic: fuel tank - removal (Read 6671 times)

B318M42W · « **on:** May 04, 2009, 12:29:53 PM »

Hi,
My fuel tank is full of rust and I don't have 250+$ to put into it...
SO... here are my questions...
has anyone taken it out? how difficult? time?
and i'm a little worried about take out the driveshaft as you need a special tool for that. how difficult is it to take out the driveshaft? procedure? precautions?

thanks!

papercutout · « **Reply #1 on:** May 04, 2009, 04:32:50 PM »

Driveshaft/propshaft over here (long 1 from gearbox to diff)... No special tools at all!

Procedure, just:

Remove exhaust from downpipes back totally.
Undo bolts that hold prop to g/box and to diff (mixture of 16 and 17mm and mebbe 15's too).
Undo centre bearing on propshaft.
Lower propshaft (this is where you'll realise removing exhaust from downpipe back is the way to go - I didn't do that, just from the centre and it was a pain!)
Try to drain fuel tank (good luck! Although if its scrap, you may be able to just punch a hole in the bottom) (having released fuel pressure of course)
Open inspection hole under the rear seat, undo all the fuel pipes etc.
Undo filler pipe.
Undo all 4 bolts that hold the tank up - 2 front, 2 rear (under the subframe, they are a nightmare! I used a tiny 3/8" socket set, make sure the sockets are single hex or you'll strip the nuts)
Drop tank down. To remove the fuel pump just twist it and lift.

Now reverse proceedure! Make sure you get the fuel pipes on the right way round, everything is done up OK, wires are connected and not trapped by fuel tank etc etc.

I pray to God that your fuel tank mounts aren't rotted away like mine were! They're a pain to try to fix! I did it though - lots of welding later! One of them actually ripped out. I'd say before you do the whole thing, remove the rear seat and look at the sound proofing. Being over the pond, you'll probably be less rusty than any here!

B318M42W · « **Reply #2 on:** May 04, 2009, 04:51:34 PM »

thanks! especially for the prayers! so it wouldn't be a real hard job after all? It seems pretty much strait forward, but i'd still like more details about the propshaft. The bentley manual isn,t very clear... like where's the threaded sleeve and is it a standard thread?

papercutout · « **Reply #3 on:** May 04, 2009, 05:58:14 PM »

I think the threaded sleeve its referring to is the one right by/at the centre bearing. Just undo and pull off. If its too tight to do by hand, an adjustable spanner will be able to do it! Its standard thread and easy.

Realistically it shouldn't be too hard a job. Mine was aweful thanks to the tank mounts being rusted in place and having to rip one out, and so weld fresh metal in and measure it up right etc. Also lying on your back on a gravel driveway with the car 3" above your nose is a put-off!

If you're mechaincally minded at all, you'll be fine. Just remember to stick to single hence sockets, and have spanners in these sizes too: 13mm, 14mm, 15mm, 16mm, 17mm. (not essential, just helpful).
I removed most of my heatshielding at the same time btw, I couldn't see a problem personally, but its up to you.

B318M42W · « **Reply #4 on:** May 04, 2009, 07:47:34 PM »

great! fuel tank is coming out in that case! oh and one more question... can the rear wheels spin without a consequence when the propshaft isn't there anymore? ie: no angle/position specific balancing issue, since will most likely be pushed into the garage, take tank out and push car out again (since it's not my garage... and it takes at least 1 week to completely overhaul the tank by my own)

nicknikolovski · « **Reply #5 on:** May 05, 2009, 04:35:29 AM »

Before you remove the tailshaft/prop shaft/driveshaft what ever you want to call, mark the position at each section that you remove.

So mark the position where the tailshaft meets the gearbox, mark the position where the tailshaft meets the diff, and if you are going to seperate the shaft at the centre bearing mark the splines as well. Good luck

papercutout · « **Reply #6 on:** May 05, 2009, 02:18:24 PM »

Yeah? Does it make any difference? I didn't do it and I've had no problems! And I'm convinced my wheels would have been turned! And I KNOW the splines will be in a different place!

Do it if you can I guess, tho I've been basically problem free (although the centre bearing mounting bolts loosened off once, so I just tightened them again). Mine was on axle stands, but still...

Good luck mate!

sports.racer · « **Reply #7 on:** May 05, 2009, 04:42:47 PM »

In a related question, the fuel line that goes into the fuel filter is leaking on my car. Can I get that line out without removing the tank? Can't really see what's securing the fuel line. Apartment parking lot, no jack, no jack stands, what a PITA!

The leak is close enough to the filter that I can splice in a short piece of new fuel line but if it's not too much trouble I'd rather just put in a new line all the way to the fuel pump.

Anyone know what the ID of the fuel line is?

Thanks!

papercutout · « **Reply #8 on:** May 05, 2009, 05:01:33 PM »

The hose is 5/16" hose. (6mm I think)

The fuel line is rubber from the fuel filter to the metal pipes under the car, just replace that. Its less than/about 1meter. To replace the line to the pump means replacing the metal tubing, which is a pain and pointless if its fine

To get to it by the fuel filter, park the car JUST on a kerb, pull fuse box up (not sure where it is on a LHD car though, but thats for RHD ones) and get pipe off the fuel filter. The crawl under the car, trace the line to the metal piping, undo and replace! Easy.(ish)

B318M42W · « **Reply #9 on:** May 05, 2009, 05:26:01 PM »

thanks for all the help! I was looking at the tank vs the height of the car... and i was wondering how high do I need to raise the rear of the car (@ the rear subframe) to get the tank out??? 18" sounds reasonable?

sports.racer · « **Reply #10 on:** May 05, 2009, 10:27:33 PM »

Quote from: papercutout;71410

The hose is 5/16" hose. (6mm I think)

The fuel line is rubber from the fuel filter to the metal pipes under the car, just replace that. Its less than/about 1meter. To replace the line to the pump means replacing the metal tubing, which is a pain and pointless if its fine

To get to it by the fuel filter, park the car JUST on a kerb, pull fuse box up (not sure where it is on a LHD car though, but thats for RHD ones) and get pipe off the fuel filter. The crawl under the car, trace the line to the metal piping, undo and replace! Easy.(ish)

Isn't there a rubber hose from the fuel pump to the inlet of the filter?

Are UK cars plumbed differently? Surely not.

Realoem.com isn't much help with this.

DesktopDave · « **Reply #11 on:** May 06, 2009, 10:49:56 AM »

The fuel line goes from the tank pump all the way down to the inline pump, thence to the filter, thence to the fuel rail. You might be able to snake a new line, but I'd do a splice.

I have to get at the fuel line on the car too, right at the fuel filter. There has to be a leak there - I can smell gas after a drive. The fuel line seems to be a mix of 8mm/12mm (ID/OD) and 6mm/10mm?? ID/OD and some OEM rubber pre-bent fuel lines. RealOEM tells me that there is a secondary pump at the filter, but one isn't there. I'll let you know what I dig up this afternoon.

Not sure which line goes where, but in any case 8mm ID=5/16 fuel line. Make sure you get the high-pressure fuel line for injection, not fuel hose for carbs. I also have to replace a bunch of those factory fuel line crimps. I'm hoping they're not original.

The hose on the 325is is definitely 8mmx13mm high-pressure BMW OEM fuel line, and it's lasted so much better than the cheap 5/16 bulk stuff the PO used. Original date stamp too. Unfortunately it looks like I have a leak on the metal line from filter to engine on the 318i.

I'd figure two feet minimum to take out the tank. You'll have to pull the exhaust and drop the diff too. Driveshafts might get in the way. Looks like a real pig of a job...I might be tempted to drop the whole subframe as my bushings need replaced. The tank is really stuck up in there.

papercutout · « **Reply #12 on:** May 06, 2009, 11:53:05 AM »

Quote from: sports.racer;71427

Isn't there a rubber hose from the fuel pump to the inlet of the filter?

Are UK cars plumbed differently? Surely not.

Realoem.com isn't much help with this.

In a UK car the fuel pump is in the tank, right hand side of the car (sitting in the car facing forwards). The rubber lines run across the top of the tank to the left side, then clamp onto metal pipes that run all the way to the front of the car. They stop by the engine bay and you then run rubber pipes to the fuel filter/fuel rail.
Hope that clarifies!

Quote from: B318M42W;71413

thanks for all the help! I was looking at the tank vs the height of the car... and i was wondering how high do I need to raise the rear of the car (@ the rear subframe) to get the tank out??? 18" sounds reasonable?

Should be fine. Higher is nicer of course! To get the tank back up, I advise having a friend lying under the car with you, just so they can hold one side while you hold the other so you can get the bolts in btw!

sports.racer · « **Reply #13 on:** May 06, 2009, 04:48:21 PM »

Quote from: papercutout;71465

They stop by the engine bay and you then run rubber pipes to the fuel filter/fuel rail.
Hope that clarifies!

Maybe the fuel filters are installed in different locations on a 325 than a 318is? On my car the fuel filter is underneath, right behind the driver's seat. It appears that there is a rubber hose from the tank to the filter, then the filter and another sort piece of hose from the filter to the hard lines that run forward.

I just need to stop typing and get out there and fix it.

Thanks for the hints though!

papercutout · « **Reply #14 on:** May 07, 2009, 04:37:58 PM »

Yup - different place on 6 cylinder cars! All 4 pots have it in the engine bay, 6 pots have it where you said. Being a M42 forum, I assumed you had a 4 pot

Sorry dude!

Hope you got it done OK.