1520 engine hole needs plug

Jnasystems · Nov 1, 2014

my tractor had been running like a top till one day when all the oil poured out of it. Luckily I was there and turned off the tractor before anything too bad happened. In looking into it, it looked like it was coming from the top of the engine at first, so I started taking the valve cover off and was about to start removing the head when I decided to fill it back up with oil and see if I could see where it was leaking. it held the oil, so I started it back up. Found the leak... there is a port on the side of the engine behind the hydraulic pump that was open. I looked it up on partspring and I thought it was the 1/8" NTP plug that had fallen out, but when I tried to put the plug in, the hole was much too small. I thought, ok, lets try a couple bolts and see if one fits. None did. So I started wondering if the hole was threaded at all - nope, it doesn't seem to be. So my question is what do I use to fill this hole? I have attached a picture to help see what hole I am talking about.

The hole is the clean spot circled in red directly above the casting number and to the left of the pump on the right of the shot. With the engine on, oil just pours out of that hole, so I assume it is in an oil line cast into the block, so I would think it would see some pressure and a plastic plug would be insufficient, but maybe that is what is needed here. Any thoughts are appreciated.
Thanks,
Joe

2458n · Nov 1, 2014

Had the same problem with a Kubota engine. Cold weather start and I was in the seat when my plug blew out into the snow. You were lucky to catch it so quickly. A good parts man got the aluminum plug for me. I cleaned the hole with brake cleaner ,before putting loctite on the plug and hammering it home. I was told to take a nail punch and stake the plug in by punching around the plug in the cast iron around the hole. Instead i took a dremel tool and ground the paint off the engine around the hole. I covered the spot with JB weld and have not leaked since. A friend said I should have used a tap with grease and fixed the hole with a bolt. I did it the way I did because I was able to get the factory alum. plug from a dealer. The first two dealers did not seem to interested with my problem. Good luck- there was on threads in my hole just smooth like yours.

Jnasystems · Nov 1, 2014

Thanks for the info!!! I could certainly tap it if that is the best way to deal with it. Would probably be cheaper too. Alternatively, I may be able to make a plug out of aluminum with a hole for a bolt that would kinda make it like a concrete anchor if that makes sense. My next concern was that it was a designed failure point to protect some other part of the engine and plugging it too tight may not be the best idea.