oil sender unit

[NemisusDM]

Hey Guy's,
I have a leak at the oil sender unit and can't seem to find any info. I don't know what the torque specs. are or how far down to tighten etc. I planned on wrapping some Teflon tape around it but, I don't want to overtorque it.

Thanks,

[3Phase]

The torque book says:

2.0 m-kg (14.5 ft-lb) Use LOCKTITE

Is it leaking around the threads or from the top where the wire hooks up?

Regards,

Scott

[NemisusDM]

Hey 3Phase,

It's leaking around the threads....
Blue or Red LOCKTITE?

Thanks,

[jjwaller]

None of the above.
Three wraps of teflon tape, and possibly a light coating of pipe dope should do the trick.
Works on my industrial stuff up to 3000 PSI.

[blue giant]

Not all Teflon tape is gas and oil friendly!

Blue locktite if you have it will work just fine.

[jjwaller]

Originally posted by blue giant
Not all Teflon tape is gas and oil friendly!

Blue locktite if you have it will work just fine.

That is a myth or urban legend. PIECES of teflon tape are not friendly to small fuel orifices. The teflon is completely suitable for just about all liquids. Locktite however, is a thread locker and not designed to seal liquid pressure. It might work when set, but not what it is designed for.

[NemisusDM]

I thought PTFE was chemically inert?
I know it begins to deteriorate after 500 °F. How hot does that oil sender get?

Both loctite and Teflon tape sound reasonable though....

[79XS11F]

Use the YELLOW Teflon tape that is spec-ed for gas fittings. You can get it at HD. A few wraps of that stuff (counter clockwise) and your set.
Rob

[3Phase]

Cool thread you got started here, Nemisus!

Sorry, I didn't mean to just post and run but I'm still working on making that color schematic for my bike. When I start to see inverse color lines everywhere I look it's time to take another break!


The book says to use Locktite so I passed that along with the torque range. Now, the book doesn't say what kind of Locktite to use but from the fasteners and applications they list on the torque spec pages I assume (danger, Will Robinson!) they mean the blue Locktite.

The threads themselves are supposed to make a mechanical seal, not the Locktite. Locktite keeps threads from coming loose and keeps steel threads from galling or seizing in the aluminum engine case so you can separate them without re-smelting the engine case and fishing the steel fasteners out of the bottom of the crucible. Locktite fills the tiny voids in the threads, so it will act as a sealer if the threads are in good shape. For a while, it'll seal even if the threads are not in good shape.

If the threads are not in good shape, make them again with a good shape.

The temperature rating for Teflon is the maximum peak temperature and not the sustained temperature. Teflon and other thread sealers and lubricants can actually make things worse if you try to use the factory torque specs for both dry and oil fasteners.

Any fastener will be too tight by the time a torque wrench even begins to get close to a torque spec that does not specifically call for Teflon. In aluminum, you can strip threads, break fasteners and crack fittings with a quarter inch drive ratchet from a nameless discount store's basement bargain bin and one hand tied behind your back.

Personally I use ARP or equivalent thread sealer and adjust any torque settings accordingly, but you can use almost anything for a loose oil sending unit. Leather was used for centuries as a durable seal. Find that guy that runs his XS on dead rats and kerosene and see if he has any spares. Soak one of the dead rat tails in the kerosene to soften it up a little, then use it to wrap the threads instead that spendy Teflon tape.


Regards,

Scott <-- back to that dratted full-color schematic

[NemisusDM]

Hey Guys,

Well I used teflon tape and I still have oil all over the sender unit. The tape should have stopped oil passing the threads so, I suspect it's coming from somewhere else.

[skids]

I suppose it is time to really scrub it up and find out where...maybe the oil pipe seal? I think that is a copper crush washer.

Originally posted by NemisusDM
Hey Guys,

Well I used teflon tape and I still have oil all over the sender unit. The tape should have stopped oil passing the threads so, I suspect it's coming from somewhere else.

[NemisusDM]

pipe is bone dry...
oil is on the sender unit and puddled behind the engine...

[Jerry]

JAT...
A leaking cam chain plug will allow oil to migrate from the front of the engine and pool aroud the oil send pipe. Don't Ask Me How I Know This (DAMHIKT) but I spend some time tracking down this "oil leak" and it turned out not to be the sensor at all.

Leak was bad enough that oil would run down both sides of the engine cases.

I replaced the gasket under the cam chain tensioner and replaced the plug in the end of the tensioner. Be careful if you go this route that you don't mess up the cam chain timing! If your cam chain needs replacing, is also a good time to do that.

The sender can develop a leak and need to be replaced; I had this happen on another bike (XS 400) and a Toyota Tercell car sender, so is not out of the question.