Fuel Leak at the in tank fuel pump

[Mike Wenrich]

I have a 2009 E1200RT and I'm trying to repair a leak where the fuel line exits the tank under pressure to the injection system.  I first replace an O-Ring on the plastic elbow.  That slowed the leak and then I replaced the elbow.  Slowed it again but still leaks.  If I press down on the elbow it appears to stop the leak.  Since I don't know what else is in that connection I would like to know if I can apply a small amount of Permatex No.2 to stop the leak.  According to the parts man at the dealer this is a problem connection and sometimes the plastic elbow cracks.  Dealerships are far from my location so I would like to avoid making that trip twice to repair what seems to be a minor leak.


Any advice appreciated.---Mike

[David.]

Could the leak be coming from the fuel line coupler/flange on the tank, rather than the plastic elbow itself.

This photo shows a crack in the flange on the tank.



Some models have a reinforcing metal ring fitted.



Beemerboneyard sell both a repair clamp, https://www.beemerboneyard.com/rk12fuelpmpclmp.html and replacement brass fitting, https://www.beemerboneyard.com/cpcqkdcfemaleth.html

Sounds like these are known problems with Hexhead RT's.

[Mike Wenrich]

It could be the fitting.  I don't know what the internal parts look like and it definitely is coming from around the metal ring like in the second picture.  I see it seep up between the ring and the elbow.  But when I press down on the elbow it stops.  I suppose like the snap connection is a little too large for the O-ring to stop the fuel from passing by it.

[David.]

But when I press down on the elbow it stops. I suppose like the snap connection is a little too large for the O-ring to stop the fuel from passing by it.

Looks like there is room to try an O-ring of the same internal diameter but slightly larger section. If the original O-ring is say 20mm ID x 2.5mm Section, (might be on the packaging),  then a 20mm ID x 3.0mm Section might do the trick, https://www.georgelodgedirect.co.uk/Pro ... gLdpPD_BwE

[Mike Wenrich]

When I look at the replacement parts from Beemer Boneyard it appears the quick disconnect part in the tank might be the problem but the complete metal assembly only comes in a 4 part kit if I am reading it correctly.  Two of the parts in that kit are not for my bike?  If I got just the brass fitting then I would still have the plastic elbow.  Since it is now new, it could last quite some time.  The model numbers listed on the site are not always mine so I would probably need to call the company, which will have to wait until tomorrow as they are closed now.


Using a larger o-ring might work too if the leak is there and not in the fitting.  The fuel creeps up between the metal ring and the fitting so it's hard to tell which part is at fault.

[David.]

The fuel creeps up between the metal ring and the fitting so it's hard to tell which part is at fault.

Can the female connector be unscrewed from the fuel pump flange, threads cleaned up & resealed using an appropriate fuel rated thread sealant.

Hopefully, the metal ring has prevented the fuel pump flange itself from being the problem.

[David.]

When I look at the replacement parts from Beemer Boneyard it appears the quick disconnect part in the tank might be the problem. If I got just the brass fitting then I would still have the plastic elbow. The model numbers listed on the site are not always mine so I would probably need to call the company.

This looks like the brass fitting for an R1200 Hexhead, https://www.beemerboneyard.com/cpcqkdcfemaleth.html

MotorWorks in the UK sell this plastic one, https://www.motorworks.co.uk/vlive/Shop ... 5_35_GA_60

[David.]

BMW R1200GS Fuel Leak 2004 model, https://www.youtube.com/watch?v=XaLh76hW7Nw

See comments.

[Mike Wenrich]

Thanks David.  I will call later today when they are taking calls.  I was a bit concerned about attempting to remove that fitting not knowing what else is connected below.  Still do not know the answer to that but it appears to be a simple job.  With the parts I threw at it and the leak becoming getting better I was not thinking the fitting would be a problem.  Now I believe it is.  Just need to know which part to order.  I would rather replace a faulty part than put sealant in there and have a bigger mess later if it did not work. 

[David.]

Interesting that, the fitting is not available as a separate item from BMW, you have to buy a complete fuel pump assembly for £407.00,
https://www.online-parts.co.uk/bmw-bike ... -part.html

Top of fuel pump assembly.


This shows what is beneath the top.

[Mike Wenrich]

That explains a lot.  Would you know if the metal support pries up and then you remove the fitting?  I don't want to crack any more plastic than is already there.

[David.]

Would you know if the metal support pries up and then you remove the fitting?

Have a look at this video & fast forward to 22:00, it shows the fitting being unscrewed from the flange without the metal ring being disturbed.

https://www.youtube.com/watch?v=xdyHT3pGm_A

36:52 to 38:46 shows the fitting being replaced, this guy used PTFE thread tape on the threads to make it fuel tight.

[Mike Wenrich]

Very good video.  Learned a lot and I received the new metal parts in two days.  I'm now prepared to replace that item.  The supplier told me there are other plastic connections that will eventually fail beyond this one near the carbs and on the other side.  He sold me a kit with the additional metal fittings.  I did not notice those before so will have to remove the plastic on that side again.  Thank you for the the video.  I might have missed that little o-ring at the bottom of the fitting in the tank.  That fitting looks pretty easy.  Not sure about the others yet.


BTW, I asked about the black plastic fuel lines right after the fittings that are preformed and he said they are made of different material and are not affected by ethenol fuel like the quick connects.  Hoping to be back on the road again soon.

[jackronner]

I've got an absolute jet of fuel I've traced to the plastic fitting that connects the fuel delivery hose to the top of the fuel pump assembly.  I've removed it, and there is an o-ring at the bottom of the connector, and there is a groove at the very top that is empty, but appears to be meant for another o-ring.  I'm tempted to go to an auto parts store or even a hardware (ironmongers) store and find the right size o-ring.  Do these rings have to be fuel-resistant? 
A second look at the female part of the elbow descending into the pump unit shows at the top of the the elbow where the empty groove is (which I'm wondering if it's not for an o-ring but rather where the snap-ring pops in?) is cracked all the way round, permitting the fuel to jet out.  The inner, yellowish, part of the female is spring-loaded and appears to move within the black part which has the groove.  Thru the crack, I can see the yellow part moving up and down.  It seems unlikely that the black part is simply a sleeve, so perhaps it has somehow cracked, but if it is designed as a sleeve, perhaps an o-ring is simply missing (there was no sign of it on or around the pump/elbow unit).[align=right][size=0.85em]



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