Fuel Leak - yikes, just before a big ride

[fpgirard]

Wrenchers - need your help here. About to embark on a long ride and just did the valves on the bike when I noticed that I have a fuel leak just below the fuel disconnects to the tank. It involves the seam between the hard plastic fuel line and the rubber fuel line that connects to the quick fuel connects to the tank (see pic below). I suspect that the rubber fuel line's radial cracks are leaking. I'm thinking that I can replace these 3 inches of rubber fuel hose but am concerned how the new clamp (replacing the crimp clamp) bears down on the plastic fuel line. Is there an insert or something that prevents too much pressure from crushing the plastic line?

Any insight here?

[garr2]

Yes those elbows are rigid - to avoid crimping when they do a 90 degree turn towards the regulator.
But the question is how rigid?
Are they plastic or plastic coated metal? I don't know.

Without the hard facts to go on let's go with a bit of speculation.
Those fuel lines are the high pressure line taking fuel from the tank to the regulator and the low pressure line taking fuel back to the tank.
On my 1150RT the top hose is the high pressure hose.



Because of the high pressure we have to use fuel injection hose and fuel injection hose clamps that have to be seriously tightened to seal properly.
I'm speculating (which is a fancy word for guessing) that those rigid lines can take serious tightening. Because the fuel injection hose clamps apply pressure evenly around the circumference of the fuel line & pipe they are unlikely to cause the rigid pipe to collapse. It goes without saying that in doing the repair you would use fuel injection rated fuel hose & fuel injection clamps.

Having said that though I'd hate you to bet your long ride on my guess work.

Ian

[kirby]

3467

[Sunbeemer]

Same thing happened with mine in the same place. And funny, the leak got worse when the weather turned cold, but would stop after the engine warmed everything up...for a while. I tried re-crimping the Oeticker clamps and that lasted about 3 weeks, but the hoses had cracks in the inner liners and needed to be replaced, which I finally did.

I had to cut the old hoses off the Quick-Disconnects with a razor knife, careful not to knick the plastic barbs, and replaced both pieces with 5/16" Goodyear Fuel Injection Hose SAE J36R9 and fuel injection hose clamps, the kind with a small bolt and nut on one side that pinches the clamp around the hose. Be sure to use Fuel injection rated hose because regular fuel line won't hold the pressure and will result in more than a small leak!

There is a short metal (brass?) insert in the end of the plastic fuel line (maybe an inch long) that prevents the line from being crushed by the clamped hose, so you don't want to slide the hose up that pipe too far and put the clamp way up thinking it will seal better because it will crush it...

Take some care pulling the old hose off that pipe by holding it firmly just beyond the end of the hose so you aren't trying to straighten out the bend as you pull the hose (which might crack it). The leaking one came off the pipe easy (it was loose), but the other one took some pulling.

And sooner or later you'll probably want to replace those failure-prone plastic Quick-Disconnects!

Good luck and have a great trip!

[jrsndman]

Just last week I replaced the fuel line in question and the quick disconnects. Only took about an hour including tank removal and reinstallation. I used the quick disconnects and fuel line from Beemer Boneyard.

Take a look here, you'll find plenty of info.

[CycleRob]

That leak is just an old shrinking/hardening hose held in place by a clamp that has to be squeezed with a tool to tighten it further, with short lived, risky results. It really should just be replaced with a genuine fine threaded screw & nut EFI clamp and new rubber EFI hoses.

Yes, there is a brass insert in the rigid plastic lines, about an inch long. I remember seeing it after it was cut out of a cracked pressure regulator fuel line. It also has the expanded retention ring that holds it in place and keeps the hose and clamp from being blown off the line. A new assembly, which includes 4 of those hard plastic lines (inlet pressure, fuel return, TB-L, TB-R) and the female socket for the pressure regulator assembly is like $100 and takes a long while to replace it . . . so treat it with aware-care when you are wrestling with the clamps and hose removals/installs.

Ahhh, those were the good-old days of R1150R ownership with its' 10 fuel line clamps, 6 separate rubber fuel hoses, a difficult to change in-tank fuel filter, 2 QD's, a heavy metal fuel tank and 3 separate oil supplies. Contrast that to the less maintenance intensive F800ST which has NO fuel filter, a thick plastic underseat lightweight fuel tank, only ONE smaller diameter fuel line, just 2 of those same factory quick-n-dirty squeeze-loop clamps and 1 oil supply. Quite a difference, isn't it? Almost 20K miles of gas/oil/tires/filters and no worries (except for the eagle eyed LEO that may be following). The newer generation BMW's (with the very short metal valve stem screwed into the side of the front wheel spoke) sure have a lot more simplicity, weight saving and greater performance engineered in. If you're still in love with the shaft drive Boxer experience, the R1200R is on your Bucket List, near the top.

[fpgirard]

All - thank you so much for the great advice. Headed to Bob's BMW today to pick up EFI hose and clamps. Will keep everyone posted. The odd thing is that it's not leaking this morning - i guess it's a function of pressure/temperature. In any case, it's gotta get replaced before this 2,500 mile trip.

CycleRob, your awesome writeup on the final drive saved my bacon last fall. It was invaluable.

pas

[fpgirard]

Can't thank you folks enough. It was easier than I thought. Knowing that there was a brass insert inside the plastic tubing was key. Taking the old EFI hosing slid off easily on that side but on the brass quick disconnects (from beemer boneyard) was a tad harder - cutting it away made it simpler.

I even remembered to seat the throttle cable properly!

Here's an after picture:

[garr2]

Can't thank you folks enough. It was easier than I thought. Knowing that there was a brass insert inside the plastic tubing was key. Taking the old EFI hosing slid off easily on that side but on the brass quick disconnects (from beemer boneyard) was a tad harder - cutting it away made it simpler.
I even remembered to seat the throttle cable properly!

And from go to woe inside 24 hours!
I wish I could get a mega expensive tradesman to just return my phone call within 24 hours when something goes wrong around the house. Anyone out there want to start up http://www.washingmachine.com or http://www.toilet.com or even http://www.haemorrhoid.com!

Ian

PS
The cyber gremlins inserted the links and granted my wish!

[fpgirard]

I'm getting just enough experience that I can start to help others on this forum. Yesterday when I saw that leak, I was woeful - how could I have missed it before? How long had it been leaking? What if this had stopped my big adventure? I feel fortunate that: 1) I found it 2) that all of you gave me great advice.

This is why I ride a bmw. What a community.

p

[BMWPA]

I noticed this leak weeks ago. Mine was intermittent but worsening--- Gas seeping/dripping out of the lower fuel line just as you described. I had not ridden in awhile contemplating whether to wrench myself or not as I have done only routine maintenance, and battery change, successfully in past but, hesitated at doing the fuel lines. Today I looked here as I have found this site very helpful/useful/informative. So, I followed your lead and fixed the problem. Excellent! I'm back in the saddle doing an 80+ mile ride today. Thank you everyone. Became a life member today.

[fpgirard]

A belated congrats on becoming a life member! It's worth it. You'll find great advice from members like CycleRob, jrnsdman, and Sunbeemer - I've followed Rob's advice in redoing my final drive and it was better than any Clymer manual.

Did a 2981 mile trip last week - from Chautauqua NY to the Tail and back. All back roads in PA, WV, VA, TN, NC & KY. Not a single fuel drip.

One of my better pics: http://tinyurl.com/8lru6er

But I do need new tires.

BMWPA - are you in Phili? Did you notice that jrsndman is from Phili? Perhaps a ride is in order....

[BMWPA]

No leaks here too, seems to be solid, done few hundred miles since the repair.
BMWPA---the PA is Physician Assistant
My home turf is Massachusetts
Ride safe, and thanks again.