Overheating???

[rpeter]

I have a B7800 with about 300 hours on it. This is it's fourth summer in southern PA. I run a 60" bush hog behind it to cut the weeds between the 10 acres of trees I have planted. I know that the 60" 500 pound bush hog is at the upper limit of what the tractor can pull. In past years the tractor has run pretty hot but it has always run. This year it overheats after about an hour of operation. It does not overheat when using the loader. I have checked the Bush Hog and everything seems OK.

Anyone have any suggestions; cause I can not figure it out????

 

[klrobert]

It sounds like you may have an airflow problem. Check to see if the radiator fins are clogged. They may just need to be cleaned out. I use compressed air.

 

[repete]

Check for an obstructed radiator as stated above and be sure and see if you have a removable screen in front of the radiator to catch grass etc.

My L2550 is a "pusher" type so my screen is between the radiator and the engine. The fan pushes the air from the engine side forward.

 

[dodge man]

Do you need to flush the cooling system? Do you have a 50-50 mixture of antifreeze and water? The water actually cools better than the antifreeze, so its actually not better to have more antifreeze than water. Thermostat and water pump are something else to check.

 

[DavidAubke]

I have similar trouble with my BX2350.

I had been pulling a 5 ft bush hog behind it and it ran very hot. After a while, the needle would creep to within about an 1/8" of the red zone. Every couple of laps I'd stop in the shade, disengage the PTO and let it cool off. When I did this, the needle would drop rapidly back to the half-way mark.

I figured it was hot because I was driving a mower that was too big for the tractor but when I took a 4 ft mower out this weekend, it started climbing right back up there.

If I mow in the evening when it's cooler and there's less direct sunlight, it manages quite well. In the daytime, full sun and upper eighties, it's really sweatin'. I figure I probably can't mow at all if it gets above ninety.

I check the radiator grill, screen and fins frequently. Since dandelion seed season ended, the screens have stayed very clear. The tractor is young.. only just coming due for its 50 hour service.

From reading this forum, this doesn't seem normal. Plenty of others have said their temp gauges stay right in the middle of the comfort zone when they mow.

 

[mozark]

My BX2350 does the same identical thing when mowing hard. If you drive with the hood open or remove the plastic shroud around the sides of the engine it will run at normal temperature, like the shroud is restricting the air flow someway. Fins on the radiator are clean as a whistle, hope someone has some ideas.

 

[dodge man]

When I bought my Bx the guy that dropped it off said people had complained about the BX's running hot. He told me as long as it doesn't get in the red, it's O.K. He told me Kubota had taken digital temperature gauges, the kind you point at various points of the engine, and taken readings when they were being worked hard, and everthing was O.K, that they weren't overheating. Mine will also climb close to the red, maybe 1/2 inch from the red, but no higher. I know if it is overheating, it will normally be puking water into the overflow bottle, which mine doesn't do.

 

[rpeter]

ThanKs for all the replies. The people on this forum are the greatest.

I had already tried everything except changing the thermostat. I guess I will try that next.

Thanks for being the best on the net!

 

[MikeInEburg]

We had this on an L2550 - I took the radiator out of the tractor and REALLY cleaned it. Hasn't been a problem since.
Mike

 

[Dr. Bob]

Just for a direct comparison, I have a 2004 B7800 with a little over 300 hrs on it and I pull a 5 ft Woods Brush Bull. I have NEVER had any overheating problem. I sometimes question the temperature gage since it never goes above 1/4 of the scale.

 

[ampsucker]

by bx24 has only 200 hours on it and runs halfway between middle and red when running just the stock 60" MMM. at 100 hours the dealer cleaned the radiator fins but it was winter. this summer, it is running just as hot as last summer when the air temp is above 90. i mow at about 2800 rpm.

i've read it may have something to do with the location of the temperature pickup sensor in relation to the thermostat or something like that. appears to be normal for these smaller diesel engines?

i'll probably document it again with the dealer for the warranty, but otherwise i'm not too worried about it.

amp

 

[herringchoker]

Just for a direct comparison, I have a 2004 B7800 with a little over 300 hrs on it and I pull a 5 ft Woods Brush Bull. I have NEVER had any overheating problem. I sometimes question the temperature gage since it never goes above 1/4 of the scale.

I have the same experience with my B7800 (225 hrs. on it) pulling a 60" bush cutter - temp never gets much above the "C". I've replaced the thermostat - no difference.

 

[ampsucker]

just did a good test today on the bx24. the neighbor asked me to mow her 5 acre, massively overgrown field. it was just at 100 degrees outside and the shortest grass in the field was about even with the hood of the tractor. tallest was considerably taller than me.

i ran with the belly mower all the way up at about 2100 rpms. the tractor was working pretty good. the temp needle would inch up all the way to the north end of the white range but never cross into the red. about every third pass around the field i would reach down and wipe off the air intake screen under the steering wheel. about half way through, i cleaned the internal radiator screen.

i'm pretty sure i could have made it go into the red if i pushed the rpms any further. if i stopped in the shade for a few minutes, the temp would slowly go back down to normal. at no time did i smell coolant or did anything boil over. i had just changed the engine oil for the 200 hour service and never smelled anything that made me think the motor was getting into trouble.

oh, and i had just tightened the fan/alternator belt which was a little loose, but probably not slipping.

anyway, tomorrow it gets a pressure washer bath and the blades sharpened and we'll be ready for the next job.

amp