Kubota Head Gasket

[Hdoilcan]

So I was on here and explained the antifreeze was coming out the overflow tube (radiator) on my Kubota B7100. I was told to take the radiator cap off and let the unhinge warm up to see it there were any bubbles coming up to the surface. I was told if there was then it was the head gasket. Well there bubbles coming up at a decent pace. Today I was told to try Bar Head Gasket Fix. So I tried that as per instructions. Well it didn’t work as it’s still getting the bubbles and the coolant will rise pretty quickly to overflow from the cap opening. Then it’ll go down and come up and over flow again ect.
Are these Head Gasket sealers known to not work? Or would the leak be to much of a leak for a sealer fix? I’m taking it needs a new head gasket. Could anything else be the problem that I can check?

 

[K5lwq]

The proper way to check if it is a head gasket or crack in the head would be do a combustion chamber leak test. Most auto parts stores will have a kit they will let you use if you buy the solution for the test. Just follow the instructions that will be with the kit.

Did the tractor over heat?

 

[Hdoilcan]

Did the tractor over heat?

I know I probably sound stupid here but how would I know if it overheated? There’s no temp gauge. The only thing I know is when I was mowing the lawn last summer, after I was done I noticed something had dripped on the mower deck so after checking it out I realized it was coming from the radiator overflow. I never seen any steam or burst or anything like that.

 

[K5lwq]

Well I am the stupid one! LOL I have never looked at the dash of a B7100. I looked at a picture just now and the only light I see is oil pressure light. I am surprised they did not put some type of indicator for coolant temp. I believe I would be adding something. These small tractors have small radiators and set low in the grass and dirt. They can stop up easily causing the engine to over heat if you don't keep an eye on temps. Even my little Satoh Beaver had a light as standard equipment. I changed it to a gauge as soon as I could because I don't care much for just a light. You might should try to get some type of a gauge installed so you can watch it. I would still do the test I mentioned to confirm that is your issue.

 

[ericm979]

The B7100 has a thermosiphon cooling system. There is no water pump. Hot water rises, goes through the upper radiator hose, cools in the radiator and goes through the lower radiator hose to the engine. The only indication of overheating is the whistle on the radiator overflow tube. When it overheats steam comes from the engine into the radiator and out the overflow. Check that yours has the whistle.

A compression test is a good idea. Make sure you get a diesel compression tester. Gas engine ones don't read high enough. The owner's manual has a lot of maintenance information and may have the compression specs. If not, the workshop manual does.