Worried

[Anonymous Poster]

I am concerned as to whether I may have damaged my B7300. I was mowing some thick dense grass and weeds when the overheat whistle began to sound. I immediately turned off the engine and raised the hood. The coolant in the recovery tank was bubbling and spewing out the temperature whistle. This lasted about 20 seconds. The dust from mowing had blocked the airflow through the radiator. I cleaned the screen and restarted the engine to check for problems. All seems well and I only lost coolant from the full mark down to the low mark in the recovery tank. I wish Kubota had installed a temperature gauge on this model. I plan on changing the oil just to be safe, before using the tractor again. I am just concerned as to whether I have damaged anything.

 

[MChalkley]

Your tractor is most likely fine. How old is it, how many hours, and has the coolant ever been changed? This will give us some idea of how hot it actually got.

I would definitely change the oil. If it's not synthetic, it's shot.

Mark

 

[Anonymous Poster]

Mark,
The tractor has 117 hours on it and is two years old. I have not changed the coolant. I have been using the oil recommended by my dealer. It is Case 15W40 oil.

 

[MChalkley]

gdaughtr - My guess is that the coolant should probably be changed, too. It's possible that it's been abused by the heat, and it's not a bad idea to change it every couple years or so, anyway. If you've had to add any water and didn't use a 50/50 mix, that will lower the boiling point of the water, as will the aging of it.

You could check it with an antifreeze tester to see the boiling point so you would know for sure, but my bet is that it's pretty low, which is good in this case, because it means that the temperature didn't have to get too high to cause it to boil.

The problem is that when it starts to boil it can't carry heat away from the hottest parts of the engine any longer, so you want to make sure it's at a 50/50 mix.

As I said before, I'd go ahead and change the oil. It's most likely ruined, and definitely not worth risking the engine over.

MarkC

 

[Anonymous Poster]

Mark,

Thanks for the info. I feel better about the situation now. I will change the coolant as well as the oil. What oil do you recommend? I had thought about using the Kubota oil, but am not sure.

GregD

 

[Anonymous Poster]

Since no one has mentioned it I thought I would...mowing is the worst for this, but even driving in the bushes and tall grass can restrict the radiator (or it's "prescreen" if you have one) The suction the radiator fan puts out is pretty high and you'll be amazed how much junk ends up there.

 

[MChalkley]

GregD, since you're (I assume) new to this board, I'll let you in on a secret that everybody here but you knows already: I'm very much a proponent of synthetics. If it's a recommendation for petroleum you're looking for, I'd recommend a Valvoline or Castrol (no reason other than that they do well in the evaporation tests, whereas some highly recommended diesel oils, like Rotella T, are terrible in this test, losing 10-12% of their volume in a test that other petroleum oils lose 5-7% and synthetics lose 2-3%.) oil that's rated CD or higher (as in CD, CE, CE-II, CF, etc.). That means it's formulated for diesels. As for viscosity, 15W40 is fine, unless you're in a colder climate northern state, in which case 10W30 would be better.

Now, if you're interested in synthetics, I can do a lot better...

Mark

 

[Bird]

GregD, I don't know what part of the country you're in, and I knew Mark would tell you about the synthetics (can't believe he didn't specify Amsoil) which I'm sure is a good way to go, but everyone I know with a diesel engine in my area, whether big tractor, little tractor, truck, or 18-wheeler (including myself) is using Delo 400 15W-40 motor oil. And I really can't say whether it's any better than any of the other oils formulated for diesel use, or whether it's just that it's so readily available. I started using it because my brother's been using it successfully in Cummins and Caterpillar truck engines for nearly 30 years, including several years in Alaska, a real farmer neighbor buys his in 55 gallon drums for his 3 big John Deere tractors, 2 diesel Ford one ton pickups, and a Cummins powered 18-wheeler, and I can get it at the handy Wal-Mart store./w3tcompact/icons/smile.gif

Bird

 

[W5FL]

Yeah Bird,

But where do you get that Synthetic Hydraulic Fluid at Wal Mart? I haven't found anyone who sells it without becoming a Amsoil dealer and selling it to yourself.

 

[TomG]

I could be wrong, but I think it's better to try to let over-heated engines cool down at idle before shutting them down--unless, of course, the engine was lugging.