MTFCA Forum

Should the threads on oil drain petcock have anything on them for a seal ? Such as pipe dope, thread tape etc.

Yes. They are tapered pipe fittings.

I use Teflon tape with good results.

Are you referring to the petcock to check the oil level? I have not seen one for the drain, and would be concerned that you might get it caught on something and loose all your oil. The oil drain is a plug. Some cars have a pipe plug and others have a hex head with a copper ring between the plug and the crankcase. If you are using the oil level petcock to drain the oil, you will still have about 3 quarts of old oil in the crankcase.
Norm

I use Teflon tape the one we used with gas. The packaging is yellow and the Teflon is thicker and much more resistant than regular Teflon.

I am referring to the petcocks to check oil level, sorry calling them oil drain caused confusion. I appreciate all the responses, I think I will use the Teflon tape.

The petcocks have a tapered thread and it is not necessary to use any sealant if they are tight, but doing so is good insurance. The tapered thread means they will tighten up OK, but they may be differently oriented. If you want to use a tool to check the levels, this may be a problem. Then the tape can come into its own by sealing up he threads on a petcock which is not absolutely tight but is left oriented as required.

Allan from down under.

I had a petcock come loose and fall out when I used Teflon tape for sealing the threads, but only tightened it to the position I wanted instead of fully tightening it.
Luckily I caught it in time so no damage occurred.