Oil Drain Plug - Onan 7500 Quiet Diesel Generator

[fagnaml]

This past Saturday (May 14, 2018) and last October, I struggled mightily to remove the 1/4" NPT oil drain plug from the bottom of my Onan 7500 Quiet Diesel generator. The small hex head on the plug had been somewhat "rounded" by the previous owner or whomever changed oil before I bought the motorhome (see attached photo). 

 Knowing I had the chance of really "mucking-up" the small 1/4" hex head on the plug (which happened), I purchased a new 1/4" NPT brass pipe plug from my local ACE Hardware store that has a larger hex head --> http://www.acehardware.com/product/index.jsp?productId=52439446&cp=2568443.2568452.2631237.2631262.2631279.2631288   This new brass plug is now in place on my generator.  The larger hex head should make it easier to remove.

The OEM drain plug has considerable hard "carbon" build-up in the threads which probably contributed to making the plug difficult to remove.  I presume the build-up came from carbon in the generator oil or thread dope used by the previous owner.

Any thoughts / concerns from the forum about using a brass plug as the oil drain plug?

[fagnaml]

The OEM plug is a 1/4" NPT plug.  Here is an OEM plug from eBay --> https://www.ebay.com/itm/Onan-Genuine-Factory-RV-Generator-Oil-Drain-Plug-181-9227-HDKAJ-Spec-J-Newer/292557041724?epid=1140350417&hash=item441dc2303c:g:-zgAAOSwJ7RYWYTf&vxp=mtr

The OEM plug fit nicely into a 1/4" pipe elbow at the ACE Hardware store to confirm it had pipe (not bolt) threads.  Also, in my posting about the EZ Oil Drain valve, their website also shows 1/4" and 3/8" NPT pipe threading for the drain valves they manufacture for Onan generators.

I don't think the new brass plug will "gall" in place as the oil temp should be ~220 F and the brass should not corrode -- Agree??

[wolfe10]

Mike,

Compare brass with the oil pan metal to see if they are "galvanically close".  OK if the brass is the anode, but sure don't want the pan to sacrifice itself to protect the plug:

https://www.pemnet.com/design_info/galvanic-corrosion/

[hermanmullins]

Just thinking. Would plumbers tape protect the threads for Galvanic Corrosion while seiling for leaks and helping when removing?

Herman 

[fagnaml]

Herman -

I had the same thought about the Teflon plumber's tape but chose not to use it.  My luck is a piece of the tape would break off and plug a small oil injection port for the crank shaft and wreck the generator.   My level of luck is also why I don't visit casino's......

[wildebill308]

3 hours ago, fagnaml said:

Herman -

I had the same thought about the Teflon plumber's tape but chose not to use it.  My luck is a piece of the tape would break off and plug a small oil injection port for the crankshaft and wreck the generator.   My level of luck is also why I don't visit casino's......

I don't see a problem. Any part of the teflon tape would be trapped by the filter before it could plug a small oil injection port for the crankshaft and wreck the generator. 

Bill

[manholt]

Hermans idea should work as long as you know if you have Galvanic reaction or not.  If you do, then make sure all parts of bolt is covered...all !  Best would be same metal as pan.