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"Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 1:45 pm
by Aitch
The battery swap was going well with the new CP680 snuggly in place. I had the tank back on and the main tank bolt installed. Managed to wrestle the first disconnect back into a connected/latched position.
Second one didn't go quite so well. It snapped, well you know where it snapped, where it is supposed to.
Anyway here I am with gas pouring out.
Superb BMW engineering on most all components... except the seat and now the disconnects!
I ran and got my chain saw gas can and drained 2.5 gallons, some of it into the gas can.
I can probably figure out some way to "Arkansas" rig it but looks like I'm in the market for some real disconnects. Dang it, I was hoping to ride today.
Now I'm soliciting your recommendations for disconnects.
Aitch
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 4:28 pm
by Airman
Aitch wrote:The battery swap was going well with the new CP680 snuggly in place. I had the tank back on and the main tank bolt installed. Managed to wrestle the first disconnect back into a connected/latched position.
Second one didn't go quite so well. It snapped, well you know where it snapped, where it is supposed to.
Anyway here I am with gas pouring out.
Superb BMW engineering on most all components... except the seat and now the disconnects!
I ran and got my chain saw gas can and drained 2.5 gallons, some of it into the gas can.
I can probably figure out some way to "Arkansas" rig it but looks like I'm in the market for some real disconnects. Dang it, I was hoping to ride today.
Now I'm soliciting your recommendations for disconnects.
Aitch
Time for the chrome plated brass disconnects from beemerBoneyard, eh ? For furture reference, the fittings are tight and need a little lube to slip together easily. I did the disconnects last summer when I changed the fuel filter. If you're in the store buying parts remember the real fuel injection hose costs 4 times as much as regular fuel line. My auto parts place tried really hard to sell me the wrong hose, and dispite what the parts guy tells you, you cannot use screw clamps on FI lines. Keep those old fittings, as you now know, they're handy for draining fuel from the tank.
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 5:39 pm
by Buckster
http://www.omega.com/toc_asp/subsection ... book=Green
You can also use the Omega's. Part #'s LCD-170-05 and LCD-220-05. A pair of each. When you do the switch, do 1 line at a time or mark lines so you don't get them crossed up when re-installing. Old fittings are a pain to get off , so use some patience.
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 5:45 pm
by Aitch
Time for the chrome plated brass disconnects from beemerBoneyard, eh ? For furture reference, the fittings are tight and need a little lube to slip together easily. I did the disconnects last summer when I changed the fuel filter. If you're in the store buying parts remember the real fuel injection hose costs 4 times as much as regular fuel line. My auto parts place tried really hard to sell me the wrong hose, and dispite what the parts guy tells you, you cannot use screw clamps on FI lines. Keep those old fittings, as you now know, they're handy for draining fuel from the tank.[/quote]
Huh...
More new stuff for this old boy. I didn't know you could not use screw hose clamps. Guess I've got more research to do.
Perhaps the installation of new disconnects is more complex than I thought.
Aitch
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 6:26 pm
by pebmr
Aitch:
I just replaced my OEM plastic QD's since I had my tank off, and it went fine. I used the ones from Beemer Boneyard. Cut off the old clamps with a hack saw blade (must have patience...) and then carefully pried off the QD's from the hose with a screwdriver and some pulling/twisting. I left my old hose in since it looked ok, but a lot of folks replace the hose while they're at it.
Good luck, and at least they didn't fail on the road!
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 7:24 pm
by Trout
Rant-On
Wow, what would we do without all this modern technology to cause us headaches? It was only a few short years ago that BMW tanks didn't have quick-disconnects. They had a simple brass hose coupling. To remove the tank, you just pinched the lines with a hose pincher (forceps, needle nose vise grips with covers, etc.), unscrewed the hose clamps, and pulled the hose off the coupling.
Go to any BMW site and you can read all about failed quick-disconnects. My last bike was stained forever from baked-on leaked gasoline.
Did the quick-disconnect really buy us anything? Is it really that much more difficult to simply pinch off the line to prevent gas flow than to fight these connectors and spend hard earned cash on fancy brass versions? How often do we really even remove the tank?
Here's an option: It's bulletproof and it's cheap. Buy a pair of 5/16" brass hose couplings and be done with it. You'll also need to invest in a pair of forceps from your local fly fishing store. They are about 89 cents the last time I checked.
No more leaks. No more broken quick-disconnects. No more stained engines. No more worry on long trips. No more swollen o-rings. No more debate about the virtues of Viton vs. Buna-N vs. Rubber. No more BMW forum threads about broken quick-disconnects.
Rant-Off
Just to clarify, you can use screw hose clamps on fuel injection line... they just need to be the type designed for fuel injection. The term "screw hose clamp" is a little generic and I think what was intended was to say you can't use the worm drive type screw hose clamps on fuel injection line. Fuel injection hose clamps have a screw on them, but not the worm drive style.
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 8:12 pm
by Sunbeemer
Sorry to hear about your trouble reinstalling the fuel line quick-disconnects, but it is better to have had them fail now than somewhere in the middle of nowhere with fuel running down on to a hot cylinder head and staining your engine paint (or worse), as has been reported too often in the past.
While your replacing them, here's a couple of things to know about...look closely at the inner part of the existing fuel lines to see if there are any cracks in the ends as these have caused fuel leakage. Replace any hoses with Fuel injection hose, as regular fuel line is not rated for the 53 psi fuel pressure of our fuel pumps. This hose will cost ~ $5 or $6 a foot; if it doesn't, don't use it. A parts store guy tried to sell me vacuum hose after I asked him for 5/16" diameter Goodyear Fuel Injector Hose meeting the SAE J36R9 specification! I guess it was too much information for him...
The crimp-on type Oeticker hose clamps can be opened up using a small screwdriver by holding the clamp with a pair of pliers and twisting and levering the crimp open. If you hold your mouth right, it will loosen enough to remove. Your better off slitting the old hose lengthwise than trying to pull it off the barbed end of the Quick Disconnect and the plastic fuel lines, which even though they're are not barbed (they're smooth), can be damaged by tugging hard on them.
Try not to pull, bend, or crush the plastic fuel lines that the rubber hoses are attached to (the ones that go to the bike's fuel delivery system). Bending them severely will crimp them and they will break. They also have short brass inserts (~1" long) inside them at the ends so that the rubber hoses won't crush them when they're clamped down tight. Use the kind of hose clamps that have a small bolt between two tabs with a nut behind one tab that pulls the two ends of the hose clamp together to tighten it (Fuel Injection hose clamps), and be careful about where the end of the bolt ends up so as not to chafe anything important (like the other fuel line!)
When it's you're done, you'll be glad you did it!
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 8:42 pm
by towerworker
I use a short piece of brass tubing and a pair of inexpensive FI clamps. When I pull the tank I use a small pair of vise grips to seal the line. No drips, no mess. Have about $4 invested.
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 9:26 pm
by Trout
towerworker wrote:I use a short piece of brass tubing and a pair of inexpensive FI clamps. When I pull the tank I use a small pair of vise grips to seal the line. No drips, no mess. Have about $4 invested.
Now that's EXACTLY what I'm talking about. Perfect.
A friend once told me that BMW comes up with solutions to problems that do not exist. I think this is what he was talking about. Expensive aftermarket Omega fittings and special fuel-resistant o-rings for a $4 problem.
Towerworker, thanks for sharing.
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 9:34 pm
by R4R&R
I broke one on a Sunday afternoon, with all local dealers closed. I had to take the car to work the next day - I was bummed! Ever since then I've kept a spare at home for those occasions. Recently I replaced them the chrome Omega disconnects - much more reliable. I don't have to worry about disconnecting them the wrong way ever again!
Re: "Quick disconnects" impossible reconnects
Posted: Sun Mar 22, 2009 11:14 pm
by Airman
R4R&R wrote:I broke one on a Sunday afternoon, with all local dealers closed. I had to take the car to work the next day - I was bummed! Ever since then I've kept a spare at home for those occasions. Recently I replaced them the chrome Omega disconnects - much more reliable. I don't have to worry about disconnecting them the wrong way ever again!
I intend to carry the old fitting plus some hose and clamps with me in the tool bag. If one of those leaks, which has happened to many on this forum, if you don't have something to repair it with, you'll be a pretty unhappy lad. Maybe with a boot full of raw fuel. With that vision firmly before me, I bought the brass disconnects from BeemerBoneyard last summer when I changed the fuel filter. I changed most of the FI hoses and clamps. I think the FI hose was about $12 for three feet, but the FI clamps were cheap, like $1 each or some such.
Having the old disconnects might be handy. Now whenever I want to take the tank off I can plug one of those in and drain all that heavy fuel into a gas can. Or... say you need some fuel for your camp stove. Some of the ADV people buy liquid fueled camp stoves just so they can do that. I don't personally think pinching the fuel line with the vice grips is that good of an idea, however practical it might sound.
Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 5:09 am
by boxermania
I'm all for the replacement quick connects, I'm also partial to what the respective owners choose to deal with the problem as long as it is safe. My motto is "To each it's own"
In the interest of keeping the information crrect and not to offend anyone there are two things that need to be cleared up.
Everytime the quick connects are separated the oring, exposed to air, will swell slightly and one must lubricate the O-rings prior to re-installation, otherwise the O-ring will be cut or the plastic quick connect will barke during insertion.
The sytem fuel pressure is regulated at 3 Bar or ~ 43 psi, some owners (yours truly) have upgraded to the 3.5 Bar or ~ 51 psi presure regulator of the prior generation K bikes for added fuel.
Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 9:13 am
by Railbender
boxermania wrote:Everytime the quick connects are separated the oring, exposed to air, will swell slightly and one must lubricate the O-rings prior to re-installation, otherwise the O-ring will be cut or the plastic quick connect will barke during insertion.
What is the recommended lube for the O-rings?
Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 9:43 am
by Phang
Railbender wrote:What is the recommended lube for the O-rings?
I use silicone grease

Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 1:00 pm
by boxermania
Railbender
silicone, as mentioned above, vaseline, silicone spray, spray wax, even saliva if there isn't anything else available......
Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 5:56 pm
by Boxer
even saliva if there isn't anything else available.....
Hey Al!...Did you get that idea from some of your special videos?

Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 6:23 pm
by Railbender
boxermania wrote:Railbender
silicone, as mentioned above, vaseline, silicone spray, spray wax, even saliva if there isn't anything else available......
I ought to be able to come up with a couple of those!

Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 8:48 pm
by boxermania
Boxer
Actually early on, during the ownership of "in a state of flux" I found the need to remove the tank, upon attempting to re-conect the the fuel lines I had a hell of a time, closer inspection revealed that I had cut an o-ring, so I went to Hebert's and got me two....for free!!!!
Tried again and cut another one, at this time it finally dawned on me that some sort of lubrication was in order and a dab of saliva went on the o-ring and voila....that was about 6 years ago.
Since then I have always used a lubricant, most of the time a little silicone spray will sufice.
Re: "Quick disconnects" impossible reconnects
Posted: Mon Mar 23, 2009 11:10 pm
by OU812
Silicone is the best for avoiding deterioration form strong solvent. My preference for sure.
