Kubota B8200 radiator / fan damage repair?

[MAArcher]

I was just mowing the lawn, stopped, and while I was distracted trying to take it out of 4x4 as I had just climbed a hill, and I had head phones on and didn't realize I was letting the engine over rev a bit, and smoke/steam suddenly started pouring out from under the hood. I shut it down quick and there was coolant pouring out the bottom.

Its too hot for me to start taking things apart and make an assessment as to what's happening, but from what I can see, it seems like it was maybe just a fluke that it happened while reved up high and that maybe something, a stick or whatever, got between the fan and the radiator. The fan blade tips are all tore up a bit and it looks like they contacted something at the bottom of the radiator, bent it, sending the fan off kilter and the blades contacted a bunch of fins. Whatever piece is tore off at the bottom is where I think the leak is from.

I won't get to look at it until tomorrow but I just thought I'd throw this out there in case anyone had some diagnostic advice and what I should look for.

Also, looks like radiators are expensive, $600. Any tips on a cheaper one would be appreciated. Thanks!

 

[imarobot]

Had a leaking radiator on a JD tractor, bought it to a radiator shop and they were able to repair it. Saved me $$$

 

[Mountainman]

If you can find a shop to repair thats probably the cheapest option. But id have radiator and fan here if you need one.

 

[North Idaho Wolfman]

FYI: You can't "Over Rev" that engine, the governor will not let it happen.

Sounds like you hit something and drove it into the fan and radiator.

 

[MAArcher]

May get lucky. Seems like its just a small hole. I pressurized it with the garden hose and this is the only leak I could find.

Any tips for repair? Bend that vein back, clean with wire weel on the Dremel and then Permatex metal fuel tank and radiator repair epoxy putty?

I have some aluminum braising rods that are for use with MAP gas but when I tried to use them for a hole in a Radison canoe I just burned the metal so I'm leery about trying it here.

 

[Russell King]

I think it should be brazed using a proper material rod. A welding shop should be able to repair that if you can’t locate a radiator repair shop!

 

[North Idaho Wolfman]

It's far simpler than that.
DO NOT bend anything back, you will do more damage.
Go to a hardware store and get flux solder brush and solder for copper plumbing.
This is used with mapp gas.
First clean the are very well with a small wire brush and brake parts cleaner.
Coat the area in flux, too much is better than not enough.
Set the bottom tank on a soaking wet rag to keep heat from traveling to tank.
Start heating area till flux melts then with flux on solder brush wipe repair area again.
Have solder in one hand torch in other.
Keep heating only the area to be fixed and moving torch away then touching solder to hole till it want to melt when touched to radiator tube.
Do this very fast, keep doing it over and over till solder starts to melt.
Once melt starts add solder and heat at same time.
Then stop and let cool, water test again.

WARNING:
If you heat this area up too much the solder will flow out of other areas and you will have more leaks.
If your not sure you can do it, use JB weld on it!

 

[Hugo Habicht]

The radiator material looks to me like copper that was soldered. Additionally to Wolfmans good advice you can add small pieces of thin brass or copper sheet over the hole. This makes soldering easier I found because the solder is sucked into the gap between the original material and the sheet over it. Good cleaning beforehand is essential.

Brazing will not work, the temperature is way too high and will melt all the low temperature solder used originally.

 

[MAArcher]

I took the easy/quick way out and used some JB Weld High Temp radiator epoxy on it and it seems to hold water without leak at hose pressure. Hopefully a new fan will come in the mail tomorrow so I can get back to mowing the jungle.

The fan belt looked original and was starting to dry out so I got a new one. Does anyone know how much tension the fan belt is supposed to have? I forgot to measure deflection before I took the old one off.

 

[WI_Hedgehog]

....
First clean the are very well with a small wire brush and brake parts cleaner.
....

I would be quite careful when doing that.

Phosgene gas is highly toxic. I would not use brake cleaner for purposes other than the intended use: cleaning brakes. There are other cleaners designed for the purpose.



(note: not my bad welds, someone thinks filler wire is like caulk)

 

[North Idaho Wolfman]

I took the easy/quick way out and used some JB Weld High Temp radiator epoxy on it and it seems to hold water without leak at hose pressure. Hopefully a new fan will come in the mail tomorrow so I can get back to mowing the jungle.

The fan belt looked original and was starting to dry out so I got a new one. Does anyone know how much tension the fan belt is supposed to have? I forgot to measure deflection before I took the old one off.

Not too tight, the dynamo and the water pump are not heavy loads.

 

[MAArcher]

Well the saga continues. Upon closer inspection, while putting the new belt and fan on, I realized somethings wrong with the water pump, it sticks and grinds in one spot. So I guess I'm buying a new pump. If only I was smart enough to have checked it before. now I have to wait on another part while the jungle gets thicker. On the bright side, at least I noticed it before I got it all back together and had it seize up and destroy another fan/belt/radiator!