How much fuel line to buy?

E28 technical advice asked and given! Troubleshooting, modifications and more.
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Al Canuck
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Joined: Feb 12, 2006 12:00 PM

Post by Al Canuck »

Hey Guys,

I'm going to replace all the high pressure fuel hose in my 535i pretty quick, but I don't know how much I actually need? I'm sure I could guess, but does anyone know an actual number, in feet? Also, is it 7mm, or 8mm throughout?

Al
Velocewest
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Location: UK

Post by Velocewest »

I just did the rear lines, main feed and CSV with 2 meters, 7mm. You might need a little more depending on how the lines feeding from the tank to the main pump are setup, my e12 has no intanke pump so it has a bigger (like 10mm) suction line. Buy extra, it's cheap.
fastpat
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Location: Travelers Rest, South Carolina

Post by fastpat »

[QUOTE="Al Canuck"]Hey Guys,

I'm going to replace all the high pressure fuel hose in my 535i pretty quick, but I don't know how much I actually need? I'm sure I could guess, but does anyone know an actual number, in feet? Also, is it 7mm, or 8mm throughout?

Al[/QUOTE]

On my car some are 7mm and most are 8mm. The US-spec size fuel ine is very high quality (German rubber is still crap in my opinion), but the metric sizes are best and rarely found outside "foreign" or "european" specialty car parts stores.
Al Canuck
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Joined: Feb 12, 2006 12:00 PM

Post by Al Canuck »

Yeah, I have access to the nice German high pressure stuff at my local import part's supplier. I'll pick up 3m, and call it a day. Thank guys.

Al
RetiredDoc
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Location: Aiken SC

Post by RetiredDoc »

Consider geting all new hose clamps to go with the new hoses.
fastpat
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Location: Travelers Rest, South Carolina

Post by fastpat »

[QUOTE="RetiredDoc"]Consider geting all new hose clamps to go with the new hoses.[/QUOTE]

I always try to snag a few BMW hose and bellows clamps when I make a foray to the Pick-'N-Pull. Take a bit of metal polish, I use Autosol in the tube, to remove the cosmoline or dirt and grime, and they shine like new.

And, they have that important BMW logo stamped on them, and they're all stainless steel if genuine BMW.
C.R. Krieger
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Post by C.R. Krieger »

[QUOTE="fastpat"]On my car some are 7mm and most are 8mm. The US-spec size fuel ine is very high quality (German rubber is still crap in my opinion), but the metric sizes are best and rarely found outside "foreign" or "european" specialty car parts stores.[/QUOTE]

For replacing 7mm line, SAE 5/16" line is way more available and the difference in size is less than 0.1mm. I know how it horrifies the purists but, if it didn't have labels, you wouldn't notice the difference.
fastpat
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Location: Travelers Rest, South Carolina

Post by fastpat »

[QUOTE="fastpat"]On my car some are 7mm and most are 8mm. The US-spec size fuel ine is very high quality (German rubber is still crap in my opinion), but the metric sizes are best and rarely found outside "foreign" or "european" specialty car parts stores.[/QUOTE]

[QUOTE="C.R. Krieger"]For replacing 7mm line, SAE 5/16" line is way more available and the difference in size is less than 0.1mm. I know how it horrifies the purists but, if it didn't have labels, you wouldn't notice the difference.[/QUOTE]

I used to think that too, until I started having leaks after about two years on the car. It was fine up until then, that's why I stopped using the US-spec size.
spinedocab
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Location: Upper Bucks County, PA

Post by spinedocab »

I just did all the under hood rubber. I used 5/16 hose because it was actually a better fit than the 8mm stuff. It is a few thousandths smaller I.D. but slid onto the nipples perfectly. Not too tight at all. Based on that I don't think I would want it any looser (like the 8m stuff).

Anyway, I eliminated the vibration dampers in the lines, and it took just about 5.5 feet of hose, or maybe a few inches less.

I did not change the tank hoses.

HTH,
Andrew.
Al Canuck
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Joined: Feb 12, 2006 12:00 PM

Post by Al Canuck »

[QUOTE="fastpat"]On my car some are 7mm and most are 8mm. The US-spec size fuel ine is very high quality (German rubber is still crap in my opinion), but the metric sizes are best and rarely found outside "foreign" or "european" specialty car parts stores.[/QUOTE]

[QUOTE="C.R. Krieger"]For replacing 7mm line, SAE 5/16" line is way more available and the difference in size is less than 0.1mm. I know how it horrifies the purists but, if it didn't have labels, you wouldn't notice the difference.[/QUOTE]

7mm is actually closest to 1/4", and 8mm is closest to 5/16". 5/16" would be way too big for 7mm fittings.

Al
Brian in TN
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Post by Brian in TN »

The most common is 8x13 mm. We stock it in meter lengths and sell by the foot. Its under $4 a foot and is good quality factory hose. I will use nothing but it. But then again...I am impartial.

Image
rs4pro3
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Location: Chattanooga, TN

Post by rs4pro3 »

Ya I picked up the Dealer 8mm stuff when doing mine. I used about 4 rolls(meter long) from Da parts pimp do do the engine bay and under car on the e30 when I dropped the m30 in.
fastpat
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Location: Travelers Rest, South Carolina

Post by fastpat »

[QUOTE="fastpat"]On my car some are 7mm and most are 8mm. The US-spec size fuel ine is very high quality (German rubber is still crap in my opinion), but the metric sizes are best and rarely found outside "foreign" or "european" specialty car parts stores.[/QUOTE]

[QUOTE="C.R. Krieger"]For replacing 7mm line, SAE 5/16" line is way more available and the difference in size is less than 0.1mm. I know how it horrifies the purists but, if it didn't have labels, you wouldn't notice the difference.[/QUOTE]

[QUOTE="Al Canuck"]7mm is actually closest to 1/4", and 8mm is closest to 5/16". 5/16" would be way too big for 7mm fittings.

Al[/QUOTE]

Yessir, you're very correct. Like I said before, I used to use the "wrong" sizes until experience taught me that was a error. (@)

So now, I use 7mm where it's supposed to be, and 8mm in its proper location. Fuel system leaks are not "funny" to me, I've seen the results of them in the past, fortunately not at my expense, but I've even seen an entire house burned to the ground from a fire that started from a fuel hose leak on a car.
Al Canuck
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Post by Al Canuck »

I picked up 2m of 7mm German made hose, and 2m of 8mm German made hose today. I will do the underhood hoses this week, and I was planning on doing the others next week. I also filled my gas tank today, and discovered that it is now leaking at the seam on the back of the tank. Just a sweat, but it's enough to stink pretty badly. Damn. Oh well, at least I have a spare, but now I need to burn off a FULL tank. Oh wait, that should only take about 200 miles in my gas pig! lol.

Al
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