Kubota G5200H frozen block

[fishman]

I was given a Kubota G5200H garden tractor by a friend who manages a ranch. The story is that it was stored overwinter after running just fine through the fall and this spring it started up, ran a minute or so, then died. Because it was old and in need of refurbishment, the ranch owner purchased him a new tractor to use, so he gave me the G5200H to fix if I could. It has about 1500 hours on it.

I discovered that one freeze plug in the side of the engine is missing, and the core plug (I think that is what it is called) is missing from the front of the engine. I found this out by dumping some water in the radiator and then saw where it was leaking out. Since I live in Texas, I can only assume that he was running straight water to have any chance of this happening.

Now, for the question: If I plug up both those holes with duct tape, water will come out the water pump weep hole. I "think" this means that the water pump internals were damaged by the freezing, but I don't know. Does anyone know for sure if this is normal, or would it only happen if the pump was damaged somehow? Messick's has them for about $135 but I don't want to spend the money if I don't have to. On the other hand, since this is a project with my young son, I don't want to order the two plugs and then immediately have water pouring out of the water pump once I start it up. He's nine, and still thinks I know everything and I want to keep from disappointing him as long as possible.

Any tips on installing the plugs? The freeze plug is about 3/4" diameter and the core plug is about 1.5" in diameter. I've read that you install and dimple with a rounded tool and a light hammer strike. Any trick to it?

I don't see any other obvious leaks, so I'm hopeful that the block survived the ordeal. There is a huge bunch of oil and gunk on the oil filter side of the engine, which may indicate a leaking valve cover gasket or something, I'll have to see. The oil is full, and this oil leak has been around a while, so I don't think it has anything to do with the frozen block.

Other than this, and a good deal of weathering, the tractor is in decent shape. The middle of the deck needs some steel plate welded on it as there are some holes there, but the rest is really solid. The tractor just needs some cleaning and perhaps a paint job if I felt so inclined.

Thanks for any help you can give.

 

[955Lincoln]

You will be teaching him how to be smart with money at the same time by explaining why you are not buying a new pump at this point.

I would replace the freeze plugs and see what happens.

Is there a way to plug up the weep hole? Bottoming tap, or rig (bailing wire, hose clamp, wire tie) a plug in the hole so the pressure won't pop it out.

 

[fishman]

You will be teaching him how to be smart with money at the same time by explaining why you are not buying a new pump at this point.

I would replace the freeze plugs and see what happens.

Is there a way to plug up the weep hole? Bottoming tap, or rig (bailing wire, hose clamp, wire tie) a plug in the hole so the pressure won't pop it out.

I don't see why I wouldn't be able to tap it and put a bolt in it. Are there any negatives with doing that? I mean, it's supposed to be there, but if I seal it up, what happens? My limited knowledge of water pumps is that the bearings are lubricated by the radiator fluid, and I'm not even sure that's right.

I like your thinking regarding a lesson for the boy.

 

[955Lincoln]

I don't see why I wouldn't be able to tap it and put a bolt in it.

That was my bottoming tap comment as I don't know how much room you have to work with. It would just be temporary plug until you have determined if the machine was worth fixing and then buy a new water pump.

I think the only purpose of the weep hole is to let you know there is a problem with the bearing or seal. My guess is a permanently sealed ball bearing that is not supposed to be in contact with the coolant.

 

[955Lincoln]

Some more things you could do before even buying the freeze plugs. Drain the oil and see how it looks. Water is heavier then oil so if you see a bunch of water coming out before the oil there is a good chance the engine is toast.

If it looks ok add clean oil and then run the engine for a brief period (do not overheat) and see if combustion pressure is blowing your duct tape off or if you can sense pressure coming out of the radiator cap.

 

[PILOON]

Shucks, coolant pressure is in the 10-12 PSI range,
Sharpen (wittle( a piece of wood and pop it into that weep hole.
Better yet, plug it with hot glue.

Either tempoty plug should be good enough for trial runs.

Good luck, have fun.

 

[955Lincoln]

Shucks, coolant pressure is in the 10-12 PSI range,
Sharpen (wittle( a piece of wood and pop it into that weep hole.
Better yet, plug it with hot glue.

Either tempoty plug should be good enough for trial runs.

Good luck, have fun.

Good ideas and much easier

 

[fishman]

Good ideas and much easier

All of these ideas are great help.

I did run the machine a bit and the oil was fine immediately afterward-not milky at all. Think I'm good.

I'm going to get the freeze plugs and go for it. If needed I'll seal the weephole with something so I can run the tractor a bit.

 

[jinman]

John, my G1800 has a similar water pump. I checked Messicks and they have the pump for around $35 plus tax and a gasket. Since they have zero in stock, you might try your local Kubota dealer. The part number for your G5200 pump is 15841-72700. Of course, you'd want to double check that number with the dealer.

I'm attaching a page from my G1800 Maintenance Manual. It shows the complete breakdown of the water pump. There is a shaft with a bushing that is sealed with an internal seal (item #4). The bushings are designed to run dry. Water is probably not a good thing for these bushings and the weep hole is there to tell you that your internal seal is bad. It probably was a victim of the freeze just as were the freeze plugs.

I sorta can see both sides of this issue. Good running G5200s will run anywhere from $1200 to $1500 with asking prices even higher. I would not pay a penny over $1500 for any G5200. There are many G1800s or G1900s with low hours for $2000 to $2500. I paid $1800 for my G1800 with 1700 hours. It's a reliable and awesome mowing machine. I understand why you can afford to spend a little money on your G5200 because you got it for free. WHEN you get your freeze plugs and pump fixed, your son can ride the "critter" around the yard with a smile on his face. Just remind him to keep his hands away from anything hot.

 

[sandman2234]

Are rubber expanding freezeplugs an option rather than exact replacements?
David from jax