Fuel pump wiring - Fixed! Now leaking at flange o-ring

[chipripper]

So, diagnosis complete. I think I figured out that the thing in the red circle above is a flow regulator, since it sits in the path of fuel returning to the tank. When I got it all apart the epoxy on the fuel side of my wiring harness was a combination of brittle and gooey. I pried some of it out with a screwdriver, and 3 of the 4 wires fell out of their posts. I think I'll buy a new part and repair this one as a spare. Pump seems to run fine, so at least I'm not looking at too big of a job. Hopefully the new part can hold up for 11 years like the first one did.





Thanks again for all the advice!

[koko64]

 

[chipripper]

Parts arrived with free candy, and a nice hardware Kit! I'll be riding this weekend! Thanks California Cycleworks.

The whole kit


The air side


The fuel side


The part is definitely different from the factory part. The epoxy? on the fuel side is clear and gummy. The wires are also heavier gauge than stock. Hopefully this one holds up at least as long as the original.   I can't tell for sure, but it looks like there is no soldier point. I think the wires go through the bung? and are drowned in epoxy. If so, this is a far better design. I'm thinking if the epoxy ever fails I will have a fuel leak, but I wont have a high speed shutoff situation (which was scary AF).

[chipripper]

Got the new part installed, and everything works again! Pics of the install below. The only notable thing was the push on fasteners didn't fit well in a few of the spots where the plastic housing is close to the posts on the flange. Between the new ones and the ones I didn't break, there were enough to get everything back together. So far no leaks, and she is running strong. I'll do a test ride tomorrow and report back!

[chipripper]

So after sitting overnight, I've got fuel coming out at the flange o-ring. The new wiring bung looks to be holding fuel, so that is a plus. Time to pump the gas out of the tank and get some measurements of the flange o-ring.

1. My factory bolts were stripping on the hex heads, so I replaced them with m6 16 stainless flange bolts, and torqued to 10nm. Could this be caused by overtightening the bolts that hold the flange on, I think the shop manual called for 10nm but it felt like a bit much as I was assembling.

(From the manual : Rotational tank flange retaining screw M6x1 10nm) <- not exactly clear but almost all the m6's in the tourque spec pages are 10nm

2. Should I just replace the o-ring, and if so o-ring or x-ring?

It looks like I can order a fairly inexpensive replacement on McMaster, but I'm not sure about the best shape, hardness, etc.

https://www.mcmaster.com/o-rings/=eebc9cffc856496a9720ceee1bdf8a38k2t4r1we

https://www.mcmaster.com/o-rings/=eebc9cffc856496a9720ceee1bdf8a38k2t4u1fp

Any advice here is much appreciated!

[koko64]

Try the fancy x ring from CCW as it takes up a bit of slack with extra sealing if you are unsure of how sound the seal is between components.

[Howie]

Try the fancy x ring from CCW as it takes up a bit of slack with extra sealing if you are unsure of how sound the seal is between components.

[chipripper]

I already had a pretty big order sitting in my McMaster cart so I went ahead and ordered this:

https://www.mcmaster.com/6540k287

The measurements are pretty damn close, so I think it might work out. The mating surface on the tank feels like it bulges up a little where the nuts are embedded into the plastic, and the factory o-ring is flattened out pretty good, so I think an x-ring should do the trick. I'll let you guys know next Friday.

[chipripper]

The good news is I wasted money so you wouldn't have too! The x-ring I ordered has the correct profile dimensions, but is too big in circumference to fit the flange. Money on the way to CCW for a correct xring, and some new quick connect orings. I should have listened to you guys, lesson learned.

[koko64]