Fuel Lines Leaking. Again...

[AndyRR]

I replaced my QDs about 2 months ago to try to correct a fuel leak that only happened one time when the bike was run after sitting in the cold. I was a little skeptical of the QDs being the only problem because some of the fuel was coming from above the connections. Anyway, I replaced the QDs with straight through hose barbs and secured them with FI screw down clamps.
Started the bike the other morning to go for a ride and test out the nice new winter riding jacket I picked up at Bob's. As it was cold the night before, I let the bike idle while I put on the jacket, helmet, and gloves. That's when I noticed a bad fuel leak. All four of the FI clamps had loosened. Significantly. Fortunately, these are easy to get at, but after tightening, there was also a leak spraying out a fine mist from one of the connections leaving the tank. It looks like I'm due for a complete fuel line replacement. Easy enough, but I am really concerned about using these screw down clamps - especially at the -can't get to without removing the tank- connections coming out of the tank. Perhaps this would be a good time to find and buy the tool that crimps the factory style clamps. I think this should be the same tool that is also used on automotive CV boots clamps.
Any thoughts, suggestions or alternatives?

[Beemeridian]

765

[Sunbeemer]

AndyRR - I think Beemeridian is right, your fuel lines are dry-rotted and lost their pliability when they got cold. Mine did the same thing had cracked the inner tubes (lengthwise) in several places, which you can see by closely inspecting at the ends. I tightened the Oeticker (crimp) clamps to solve the problem for a while, but I eventually changed the hoses and the clamps. As Beemeridian said, be sure to ask for "FUEL INJECTION HOSE" because Autozone tried to sell me a piece of identical looking Vacuum hose even after I had asked for the FUEL INJECTION hose by the Goodyear Part # (SAE J36R9). Fortunately I noticed the error, because the vacuum hose would have burst under the fuel pressure! I used the FI clamps and have had no problems.

Good luck and let us know how it goes!

[boxermania]

Actually the fuel clamps on the hoses in/out the the tank are also of the compression type. These clamps also leak, more so if the tank has been removed a couple of times since they can easily rotate on the slick metal tubing.

The best bet is to replace all the clamps with the "fuel injection type", the ones that tighten with a screw and a nut. The proper installation of the clamps is to tighten until it is snug, however, it is best to leave overnight and retighten again the next morning as the metal relaxes slightly after the first tightening and loosens up a bit.

If done this way, there will not be any problems, leaks at the clamps...

[AndyRR]

Thanks for the tips. I like the idea of letting the clamps sitting overnight, then re-torquing. I was also thinking of using a dab of low-strength (purple) loc-tite on the clamps. I know for certain that the clamps were very tight. They either loosened up as a result of the line shrinking, or vibration, or a combination of the two. They had become so loose that they could be moved around by hand.

[CycleRob]

I had the same fuel weep problem on my QD replacement solid pipes last week. Right when I started it up cold, in the driveway. I could NOT believe it !!! I know I tightened those screw+nut BMW clamps TIGHT about a month ago. They did not loosen. The hose shrank. Colder than usual temps made it happen. Each one took about a turn to a 1.5 turns to make them tight again. The weeping stopped and I would have been 10 minutes late if it were not for the fact that time doesn't matter in retirement.


3 weeks ago at Advance Auto Parts I bought 5 feet of 5/16" fuel injection hose at over $4/foot and it's going on soon. The stock fuel lines are from before May 2001 and they just told me they need to go. It looks like old hoses + cold temps = fuel weep/leak.


.

[marecycling]

As Beemeridian said, be sure to ask for "FUEL INJECTION HOSE" because Autozone tried to sell me a piece of identical looking Vacuum hose even after I had asked for the FUEL INJECTION hose by the Goodyear Part # (SAE J36R9). Fortunately I noticed the error, because the vacuum hose would have burst under the fuel pressure! I used the FI clamps and have had no problems.

Good luck and let us know how it goes![/quote]

This is not a critique of all discount parts store employees, however, I have noticed a big change in the overall knowledge of the people on parts counters as of late. In cases of critical safety issues, where specific strength or other criteria are required, it is up to you to know the specifics of what you are buying. Your safety depends on it!

[AndyRR]

I picked up hose and clamps today and they sold me the wrong stuff. I explained what I wanted and gave the part number and they gave me SAE 30R6. I questioned what he brought and explained that it was for high pressure. He insisted that unless it was for hydraulic applications, it would be OK. Looked it up and it is fuel hose, but it IS NOT Fuel injection hose. The Goodyear website specifically recommends against using it for FI. I should have known when the combined total for 3 feet of hose and 4 clamps was $6.
The hose I have has a burst strength of 175 psi (35 working)
I found fuel injection hose SAE 30R9 on the Goodyear website:
http://www.goodyearep.com/ProductsDetail.aspx?id=5144
This stuff has a 100psi working pressure and 900 PSI burst.
Suitable alternative?

[maduko]

It's not uncommon to find leaks caused by nothing more than a clamp one size too big.

And it's easy to get the wrong clamps. The screw-type are much more critical because their "range" is much less than the American-style worm gear clamp.

When we had the car shop I found an easy way to check them- squeeze the ends together then try to slide it over the fuel line. If it even comes close to going over the hose you have the wrong size clamp! Buy the next smaller size.

[AndyRR]

Here it is, forget QD's, there's no unnecessary connections at all!

Disconnecting the fuel line from the smooth black plastic lines down below was far easier than disconnecting the barbs that I had replaced the QDs with. I ended up cutting the old hose off rather than risk damaging something trying to pull the hose off the barbs.
BTW, there's been some discussion on how to remove the factory fuel line clamps. Here's my solution:

Don't ask me where to get them, they're older than I am. They cut right through though

[Sunbeemer]

Nice Job! That ought to do it!

[bruno71]

AndyRR,
Those are horse hoof trimmers. Basicly, they are toenail clippers for horses. It is nice that you have found an application for them on your iron steed. I haven't seen a pair of those since I was a kid living on a farm in Kentucky.

[CycleRob]

The hose I bought at Advance Auto Parts is fuel injection hose SAE 30R9. It's very thick walled and you can see the embedded nylon internal braided webbing on the cut ends. Just by bending it you can tell it's the good stuff by the large radius it insists on.

[boxermania]

FI hose is clearly identified as such. Regarding construction, the make up is a layer of braided rope between two layers of hose, which can be easily seen if one looks at the end.....

The idea here is to resist the temdency of the hose to ballon when the higher FI pressures are present, as the hose will then act as a pressure dampner.

[Hawk]

Those useful tools are actually "shoe removal nippers", the "Hoof Nippers" are much sharper and more delicate on the edge. And much more expensive. A good pair of Hoof Nippers is about $150 at current prices, the Shoe Removal Nippers are $25 and up. Probably Diamond is the cheapist brand currently. For Hoof Nippers the best brands are GE and Lopez. But a worn out pair (for farrier use) would work fine as end nippers and can be bought used cheap at livestock auctions and some Farrier Supply stores.

New ones are available from any Farrier's Supply Store, or online at http://www.piehtool.com or http://www.centaurforge.com.

They are tough enough to stand to professional farrier daily use for many years.

[CycleRob]

I cut the stock crush band clamps off with a Dremel cut-off disk. You need to cut & replace the clamps one at a time because fuel may leak out with no clamp, a bad thing in the presence of the cut-off disk's shower of sparks. Cut thru the clamp's protruding hoop ever so slowly/carefully so the fragile disk doesn't jam or snag the cutting slot and explode in pieces. Oh yes, there's also the possibility of fuel leaking during/after the clamp is cut, although it did not occur when I Dremel disk cut all the clamps off 2 bikes.

The Dremel cut off disk, unlike any cutting plier or tool, puts ZERO stress on the fragile plastic fuel rail lines that go to the pressure regulator under the airbox.

[Sunbeemer]

To remove my crimped clamps I ground the sides off an old screwdriver so that it could slip inside the small loop of the clamp and gently pried it open releasing the pressure on the clamp and they slipped right off.