I am an R1200R rider and materials engineer with automotive experience in metals and plastics.I have been involved in NHTSA recalls. From what I see in tribble99's photo, the problem looks to be one of environmental stress cracking--a combination of stresses in the component and some environmental factor that leads to cracking over time. The corrective action for such a problem is to either reduce the stresses or eliminate the environmental factor. The stresses can be from the tightening of the male fitting and/or from residual stresses in the plastic molded part.The environmental factor could be fuel related or it could be from external factors, such as service environment (i.e. heat, air pollutants, cleaning agents, etc.) I am not familiar with the band type fix for this issue, but one problem I can see with this approach is that injection molded plastic parts have draft on the surfaces, like bosses, which results in a taper. Hard to clamp on a taper. You also have surface cleanliness, which works to defeat adhesive repair attempts. Plastic molded parts typically have release agents applied to allow extraction after molding and this inhibits adhesive bonding repairs unless the surface is scuffed up. One other comment I have is that with a metal male fitting vs a plastic one, there is the possibility of developing higher stresses while tighening the metal one in an uncontrolled installation process.
Last edited by swall; 09-02-2013 at 08:18 PM. Reason: typo
All those key points apply here. The fuel supply and containment system is a sloppy design all around and can create multiple problems for owners. The fuel gauge strip is a separate problem, another design not fit for the real world, but not related to the fuel pump flange area issues- some of which create leaks and others that don't.
The flange materials are wrong for a starter. A flimsy plastic female fitting (wrong plastic- not a reinforced type) receives a plastic male that is easily torqued a bit too much. Its the usual pipe thread type so simply wedges the female fitting to crack over time or immediately if greatly overtorqued. A correct plastic, exact torques allowing for aging effects, or metal parts to reinforce will work for stopping that cracking at or around the female bit on the flange. Or one could redesign this attachment point to seal by means other than a pipe thread or use an altogether different type of connection at a redesigned flange. Many options available - only a question of cost and practicality about which to choose.
The system uses plastic QDs and these also fail when the male fitting cracks at its tube section which is relatively thin walled. Years ago I saw a post by an individual claiming to be employed by the maker of these bit who said they advised BMW not to use them but I can't vouch for the truth of that claim. These fittings can be damaged by careless handling and all the usual means. BMW offers metal males these days but again did nothing for bikes in service other than regular warranty coverage.
The fpc- both its design and position is another problem at the flange location, that is not related to leaks- only reliability. There have been thousands of fpc failures. BMW has made a design upgrade to the fpc and repositioned it on newer bikes but done nothing to address this on older bikes other than regular warranty coverage. Having a bike quit at speed in traffic is a safety problem IMO.
I don't know who designed the bits and selected the materials at the fuel flange but I hope they've fired him by now- the design has so many screwups a first year engineering student should see - its ridiculous when looked at closely.
Owners have created a few problems attempting to fix this mess- like overtightening a metal male replacement into the plastic female at the flange and creating a crack.
I replaced a dead fpc on mine and added a metal band to the female flange fitting as a preemptive measure to prevent cracks developing over time as the plastic stretches in response to the wedge forces of the pipe thread design.
All - Thank you for the good discussion (again, if I am posting in the wrong area, please move me) - BMW contacted me back today and told me what everyone prefaced they would tell me - Out of warranty, not original owner, costs are out of your pocket, "if" a recall happens, you "might" be reimbursed, but it is really out of BMW's hands. Thanks for being a BMW rider...
I took MarchyMan's advice and simply ordered a new OEM pump assembly from 2wheelpros.com - Cost was about $25.00 less than everyone else and I am going to try turning my own wrenches. Worst case scenario is I put the new assembly in and it doesn't work; then I go to closest dealer (50 miles) on a trailer and learn something new - Tough part is the incredible weather and being in a cage -
"Beyond my control" story was a bad decision by me and pushing a rear tire to get back home to IL from LA on a Sunday morning - Should have waited until Monday and replaced the tire with whatever I could find in Monroe - Pushed north and ended up stranded in Cape Girardeau, Mo (they are closed on Sundays and Mondays) - No damage to the bike, and with no trailer in town to rent, my wife had to come get me using a borrowed truck and trailer from friends... Really dumb choice by me that ended up costing me lots of money and a lot of 'atta boy' equity from my better half... So dumb...