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Cracked electric lines in fuel tank

RT rocket

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I've been doing some major maintenance over the winter on my '02 1150 RT. I just finished going through the internal things one does to the guts of the fuel tank for 36K miles. Filter, hose replacement, screen sock, etc. I was noticing little nicks and missing insulation in small 1/64th to 1/32nd" increments at various places in the fuel pump and gauge wiring.


It's like the fuel made the insulation brittle over time and the "checkering" happened previously when the fuel filter was serviced. There are these very small cracks all the way to the stranded core of the wires.


Has anyone else experienced this? Everything worked as it should before disassembly and I've checked the pump function after reassembly just not the gauge function yet. Should I be concerned about becoming a fireball going down the road? I didn't want to use liquid electric tape for fear it would desolve and clog things like injectors.


All Input would be welcome before I go out and earn a Darwin Award!




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As the connection ends are exposed to the fuel I don't think the insulation cracks are a shorting out issue(IMHO) I would be concerned about broken wire (Intermittent opens) though.



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Thanks for your thoughts Doctare. Its appreciated.


Seems like no one wants to touch this topic with a ten foot pole.


I've been doing some research online. I might just take it all apart again and use some solvent resistant shrink tubing over the cracks and bullet connectors I'll have to install after emptying and drying out the tank again.


I'm also going to test two part plumber's epoxy putty in gasoline to see if that might work to cover the cracks.

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Evening RT rocket


I have been holding off on your query here hoping to see some other (user friendly) recommendations.


The way I (personally) repair those wires is to either totally replace the wires with fuel submersible rated wiring- OR- use small diameter fuel-submersible-rated convoluted wire covering & slide it on over the degraded wires.


I have limited access to both the fuel submersible wiring & submersible rated convoluted wire covering but unfortunately have no idea where it can be purchased commercially.

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Thanks for your reply dirtrider. I'm not sure what convoluted wire covering is but I'll start researching it.


If all else fails I'll solder in new wires.


I enjoy reading your replies DR. You truly are a sage!



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Interesting topic.


I have no idea but have you tried to buy the wire off BMW?


The other thing is, I have never seen wire degraded by oil or petrol on a car or bike in the last 50 years. Maybe it's just ordinary wire and that's why it's degraded from all those years of immersion?


Stick some wire in petrol for a couple of days and see if it goes sticky. If not I would just replace it. I think that would be better than shrink wrap.



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You should look for ETFE insulated wire: it was specifically designed for applications in aggressive fuel mixtures, like ethanol-added gasoline. You may be able to obtain it through aircraft supply stores.


Failing that, a wire marked as PTFE or Teflon insulated should do the trick and be easier to find.

PTFE is not as resistant as ETFE but far more than ordinary insulation and easier to obtain.

Teflon is a brand name which is used for a variety of coatings, all displaying from good to excellent fuel resistance. If you are extremely lucky you may get PFA insulated wire, which is effectively inert to most solvents (meaning most of the fuel components). You may have luck looking at a local industrial supply place, though most of them carry 500ft spools. ;)

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PTFE is pretty decent wire to use. ETFE resists solvents better but it is also more brittle. Since in filling the tank with gasoline it can slosh quite a bit since the wires are exposed, I would probably stick with PTFE.


A quick test of your wiring with a finger nail pressed into the wire. If you are gouging or making an indent in the insulation, it is the wrong type of wire to use. PTFE is good up to 600F for a melting point. ETFE is good up to 500F.


You can find it on Ebay if you don't have an airport nearby. Get two separate colors with one being RED so you can keep the positive lead clearly identifiable. Use multi-strand not single.





Also, purchase a real crimping tool that fuses the terminal to the wire. They are not expensive. If you are using a crimping tool with one spot to indent the terminal, plan on having intermittent problems with the wiring. the wire can scootch to the side of the indent.





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Still only as good as the tool you use to crimp it with and the correct selection of terminal to accurately match wire size.

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So I've pull the fuel pump plate out again and reviewed my wiring issues.


It appears my problem is not brittle wire but nicks and cuts from previous owners and service people horsing the pump/filter plate out of the tank. Specifically the double wire connector one must unplug as soon as the plate is lifted out of the tank.


It appears to be about 24 AWG wire. Oh joy!!!!


I appreciate everyone's input. Thank you!


I'll be sourcing the best wire available and attaching crimped connectors per feccomendation.



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