I'm not trying to turn this in to a tractor forum, but the DTR members helped me get my JD going and my neighbor needs help. He has a 88' L285 Kubota (30hp) thats running hot. He has replaced the water pump, thermostat, sending unit, fan, and had the radiator checked out. He even put a manual guage on it and it still registered 220*. Does not appear to have any leaks, and no water in the oil. Anyone have any ideas what to try next?

 

www.tractorbynet.com

If it has happended to someone, it will be listed here. It's the DTR of the compact tractor world!
trust me, that is the spot for all things tractor related.

 

2 things come to mind. I'm sure he checked the little screens between the fan blades and the radiator. Maybe his doesn't have them, but my B-1750 does and they plug often and require cleaning. Another much overlooked item is the Air Filter. If it is badly plugged, it will be very rich causing excessive heat.

 

I was just over there and he checked the air filter and it was ok. Screen is clean too. Temp guage showing close to hot. But when he turns it off, it doesn't sound hot or does it have anything coming out of the blow tube. He bought it 3 yrs ago and I'm wondering if the previous owner turned the Inj pump up. Could that make it run hot? If you have 1, what does your temp run at? He hooked up a manual guage and it read 220* with a 180* thermostat.

 

Might try flushing the whole system to make sure there are no clogs anywhere.

 

WhAt about the gauge itself? If you had access to one of those infared thermometers, you could find out if it is really hitting 200*

 

start it cold with the radiator cap off. watch for bubbles and flow change as thermostat opens(new thermostat not necessarly good). check temp in radiator matches eng. temp. may be head gasket or air lock. may want to look into rad. with clear welding helmet so if it spits you don't get burned.
Clark

 

Clogged radiator tubes will do that. You said the radiator was checked, what was done? It can be clogged but not leak. Also, does it only heat up when working hard or also when driven easily? If it runs hot when driven easily, and not hotter when driven hard, it is the thermostat. Maybe you ended up with a 210 thermostat. An easy check would be to run it with no stat. Then it will have a hard time coming up to temp. And it would give you a chance to see the flow thru the radiator by running with the cap off and looking in.

Wetspirit

 

[QUOTE=Wetspirit]Clogged radiator tubes will do that. You said the radiator was checked, what was done? It can be clogged but not leak.


He carried it to a rad shop and they did some kind of flow test on it. Said it was 100%. It was running hot (per guage) yesterday just idleing. The top hose was really hot, the bottom hose was cool. Is that normal?

 

If the top hose is hot and the bottom one cool then you either have not exceeded the cooling capacity of the system and it is operating normally, or you are not getting enough flow. Remember, the engine must come up to temp, so the top hose will always feel hot during normal operation. I suspect the thermostat is keeping it hotter than you think it should be.

Put it to work and see if it actually boils. If so there's a problem. If not the thermostat is set for a higher temp than it should be. If it does boil then remove the stat and go back to work. Does that fix the boiling problem? If so get a new stat and make sure it goes in with the sensor toward the engine. I also like the idea of drilling a small hole in them before installation (maybe 3/16" max). It helps clear the air and if the stat fails you still get a small amount of coolan through and possibly less damage. Only down side is slower warm up.

Wetspirit

 

A couple things come to mind for me , head gasket which was mention above and excessive load . I have seen scoured cylinders on more then one tractor that has just been worked to death with equipment designed for a bigger tractors . What size is it and what is he doing with it when it over heats could be the answer . If it over heats under low load and after checking all else my vote would be compression getting into the cooling system some were .

 

I used a relatively new L35 rental unit some years ago to work up a yard. I hung a 6 foot Howard Rotavator with woreout tines on it (yes, the 'vator was Cat II and there was some "adaptation" done to get it hooked up) and proceeded to about kill the Kubota. Being a rental it was not necessarily PMed the way I do so we discovered the screen was clogged the first time it went towards meltdown. After pullling and cleaning the radiator screen it still wanted to overheat every 15 minutes or so so we used a water hose (no compressed air on site) to blow through the radiator to remove accumulated crud. After that we just stopped when it started heating up and sprayed water through the radiator to cool it down.

Could have been that we were using 30HP to run something that really needed alot more to work properly. Got the job done but really had to watch the temp guage. I think that the smaller tractors of any kind just do not have enough built-in overkill in their design to handle really pushing them hard, when compared to a full-size ag or industrial tractor.

Just for yucks, try a different sender for the gauge - could be the gauge or the sender is starting to go bad. Age affects everything, eventually.

 

How on earth did it even run a 6 foot howard, we have one at home and I would put anything smaller than our massey fergison 165. Low 1 with the torque forward makes it work hard.

You could also check the termostat by taking it out and throwing it in a pot on the stove with a thermometer and see when it opens.

 

Took some doing to get the hitch to be stable, but it would lift the beast without breaking anything. Like I said, the tines were well on the way to being worn out so it wasn't really chewing up a full 6 feet, maybe only 4 feet with the spaces in between the tines. The Howard was a Select-O-Tilth and I set it up for tine speed instead of depth. Since the tines were so worn we ended up doing 3 passes anyway at angles to get the ground worked well. Not very deep either. Still took everything the L35 had to scratch the surface. And I ran it in the lowest gears it had with the rpm at PTO speed - yes it was screaming at us.

Back when I was growing up working on the farm we ran the same Howard on 75 HP Leylands with little effort. Amazing to watch that thing pulverize soil 8 inches deep. I finally got a manual for it and have been figuring out that it can be used to tailor the ground from course chopping to fine dust, depending on what the need is. If you don't mind running a 10K lb tractor over the garden it makes short work of tilling the patch.