D19 drain plug

Under where the hydraulic pump was. Twenty years ago the pump was inop and I removed it and installed a front crank driven pump. I drained and changed all fluids yesterday. I sure don’t remember the shiny drain plug in the picture is actually 2 pieces; an outer shell the wrench grabs on and a solid inner core. What the heck? It drips oil. I’d like to simply replace it with a fine thread plug? I can’t remember how those hyd pipes attached here can anyone shed some light? Can I find a fine threaded plug somewhere? Thanks. Dana




Edited by captaindana - 01 Feb 2024 at 4:45am

Cap... i dont know anything about a D19 drain plug... But if it is fine thread and has a o-ring seal on it... MOST of them were called SAE PLUGS..... A #4 would be 1/4 inch tube, a #6 would be a 3/8 tube ( 6/16") .... etc ... so yours might be a #16 or #20 ?? If you had the OD, could verify that way..

That looks like a quick drain system I think. We used to install these on big diesels in the shop where I worked altho ours were a bit different. On those the outside was threaded and the other half threaded on by hand and pushed that bottom plug up to drain. Really worked well - no wrenches needed and you could stop the drain if trying to get into 2 pails.

Oh shucks. Of course I drained all of the oil and filled with new hytrans. I did not realize it needed an O-ring so I guess I have to take it out. See what I can do about that. It’s a strange set up…I know I unhooked both lines that are still nearby but have no idea how this plug worked with those flanged lines. I’ll drain her in the am. Thanks. If o ring doesn’t cut the mustard I’ll order what Steve said. I think I measured 1.21

I sure thought it was leaking where that core met the outer area, nothing to stop a leak there, I figured as it tightened it would seal. If there’s an oring it would have to be up into the female part. Crazy deal here.

I have never seen anything like that before... Is the THREADED part factory and the PLUG home  made to replace the tube fitting ???   OR WHAT ?  ......

Here is a drawing from the parts book... Looks like what Dr. was trying to describe.. It appears the "PLUG" (1) was part of the original setup... Dr. said something about a BULK HEAD FITTING (20) ... that shows above the plate and appears to push THRU the hollow plug with an oring seal ??? 

Edited by steve(ill) - 02 Feb 2024 at 8:28pm