What do some think the o-ring is there for? Why would you put tape or thread sealant on a 0-ring sealed drain plug? I suspect that some use pipe dope on their spark plugs too.

 

I have always used teflon tape on any connection between liquids.
Even though a gasket may provide a barrier.
Never had an exhaust leak from my spark plug.

 

Yes small dab of paste.

 

You are absolutely right, there is no reason to put teflon tape or paste on a straight thread where an O-ring is used to seal it. For the people that do it, Think of it this way. Everytime you put teflon tape or paste on the drain plug and screw it in, you are pushing some that was used before up into your engine, Primary and Transmission. because some of it stays in the threaded hole. Teflon tape and pipe dope are for lubricating purpose only on tapered pipe threads so they won't gauld when seated. I only use a little oil or grease to lubricate the O-ring and torque to specs.

 

^

What he said!

 

Well, I beg to differ.....................

"Thread seal tape — commonly known as "Teflon tape", "PTFE tape", "tape dope", or "plumber's tape" — is a polytetrafluoroethylene (PTFE) film cut to specified widths for use in sealing pipe threads. The tape is wrapped around the exposed threads of a pipe before it is screwed into place. Since the PTFE is malleable, deformable and impermeable, it acts a little like putty under compression, being forced into small gaps between threads in order to create an air- and watertight seal when threaded into a joint. The tape is commonly used commercially in pressurized water systems, such as central heating systems, as well as in air compression equipment and thread joints with coarse threads."

 

[quote=Ronp42;7079952]You are absolutely right, there is no reason to put teflon tape or paste on a straight thread where an O-ring is used to seal it. For the people that do it, Think of it this way. Everytime you put teflon tape or paste on the drain plug and screw it in, you are pushing some that was used before up into your engine,/quote]
I've read somewhere that if you feel you must use teflon, use paste instead of tape. The reason is that the stringy pieces of teflon tape that results when you remove the plug can find its way into the oil system and plug the piston cooler orfices. I have no idea if that is true or not. I don't use teflon at all because the o ring is designed to do the sealing, so why seal the threads.

 

Just what i need some chunks of thread sealant or teflon tape floating around in the main oil feed pickup of my engine oil pan. It took me a while to clean it out of the threads of the engine cases and not push anymore up into the engine/primary/transmission after some idiot at the dealership used it on my bike. It also hardens up enough to not let the o-ring fit in its chamfer. What ever the hell they used.

 

Just changed my oil today and I only replaced the o-ring, no teflon compound this time around. I've used it in the past but not recently and I don't have any leaks.

 

If it is not needed or recommended why does it come from the factory that way? I do not use it, my service manual makes no mention of using it and I think the service manual is very detailed in its instructions.