Tractor overheats when mowing. No dealer actions fix it. Any ideas?

[sixdogs]

My experience with electric fans is totally in high HP applications or difficult cooling problems in street rods. 400-500 HP would be typical and the electric fans of today will easily cool that engine and even allow long idling in hot weather with the sun pounding down. Most have self contained shrouds and move from 2000+ CFM to well over 3000 CFM. I don't know how to compare that to a stock fan but in situations where a stock fan will not cool, an electric fan does it with no problem.

 

[crazyal]

Don't fall into the trap of comparing a car to a tractor. They operate at different speeds. There's a reason why when you put a car on a dyno you need to put an external fan in front of it to keep it from overheating. It's extremely rare that you will use your car at 5mph while needing full power from the engine for any length of time. For a tractor, besides keeping the radiator fins clean make sure the fan belt is not slipping, that the shroud is in place, and that there's no excessive gaps for the fan to pull in air around the radiator.

 

[stevem5215]

The problem is the size of the brush hog. I know this because I have had two tractors do the exact same thing. One was our Farm Pro 2420 20hp diesel. With a 5 foot mower deck on it when cutting grass that was higher would cause it to run hot. But, when i put the 4 foot brush hog on it then it would cut 3 ft grass without an overheat. It's the amount of power drawn from the motor which causes it to overheat.

The same problem occurred with a Ford 1900 3cyl 26pto hp with a 72" finish deck i used to cut my lawn (regular ole' grass) at home. When the grass would get thick and high (not even 10") it would bog the tractor and over heat it. I tried everything on that one to get it better. Used cooler stuff in rad fluid, used to clean it every 1/2 hour, rebuilt radiator (cored and cleaned at shop). But, the mower deck was too much to swing was the real problem. Load up your car engine with a semi trailer on the back and it too will overheat as it's not capable of it.

Put a smaller mower deck on it or move to a bigger tractor.

Steve BTDT wasted sooooooo much time trying to figure it out. And it too would cool off BOTH tractors just idling for a short time and then run for a while till hot again. Yep.

 

[ptsg]

I'm with you Steve. People quite often buy mowers way too big for the tractor they have. Some times they get away with it, because the brush they're mowing is not that dense or doesn't require much horsepower.

Over here, we buy the mowers as wide as the tractor, or sometimes, slightly narrower. No point on buying wider. We do run chains instead of blades that require more HP but still, wider mower bring that much more benefit.

A 25HP tractor, would run a 3.5 ft mower here and would bog down with denser material.

 

[DK35vince]

I'm with you Steve. People quite often buy mowers way too big for the tractor they have. Some times they get away with it, because the brush they're mowing is not that dense or doesn't require much horsepower.

Over here, we buy the mowers as wide as the tractor, or sometimes, slightly narrower. No point on buying wider. We do run chains instead of blades that require more HP but still, wider mower bring that much more benefit.

A 25HP tractor, would run a 3.5 ft mower here and would bog down with denser material.

Likely because you say you run chains instead of blades on your cutter (takes more power I would think)

 

[cogboy]

The following is from John Deere Technical Manual 1468 for 410C backhoe loader cooling system operation:
"During the warm up period, thermostat (a) remains closed and coolant is directed through bypass tube (b) to suction side of water pump. Coolant then circulates through the cylinder block and water pump only to provide a uniform and fast warm up. When the coolant temperature increases to normal operating temperature, the thermostat opens, allowing coolant to flow to the top of the radiator. The thermostat also partialiy blocks the passage to the bypass tube. If the engine is operated without a thermostat, only a small amount of water is directed to the radiator. Enough coolant will flow through the bypass tube to cause overheating." Hope this helps.

 

[Texasmark]

Your post is rather long and I didn't read it nor replies. My "limited experience" has told me that if the "Loaded" RPMs are over 10% of the unloaded RPMs expect overheating and excessive wear on your engine and drive train. I usually shoot for 5% or less....that's usually no more than a 100 rpm drop on a 2600 PTO RPM limit engine. If I am plowing and find the rpms fluctuate excessively, I raise my draft lever to a higher number allowing the draft to pull the implement up sooner when hitting a large root, rock, or hard clay spot.

On mowing the draft lever wouldn't be used, leaving it in the fully down position. Solution to mowing problems, since one would have too large a mower for the available tractor HP or vegetation too thick/high for the ground speed, then either shift to a lower gear, or move over and cut a thinner strip on these areas.

 

[Rhino35]

Stevem,

That's a pretty good argument I have too big of a brush hog. I didn't pick it, my dealership owner did. He hadn't been out to my hilly property in his defense. I will try a five foot hog before doing anything more than starting fresh next year with a blown out radiator core.

I appreciate the examples you gave.

Best,

Rhino

 

[Rhino35]

Cogboy,

It helps a lot. Thanks!

Rhino

 

[Rhino35]

Texasmark,

I manipulate the throttle to hold 2,500 RPM - there is a white mark there - which is correct for the PTO and brush hog. Are you saying run it at 2,400 RPM?

You wrote; "Solution to mowing problems, since one would have too large a mower for the available tractor HP or vegetation too thick/high for the ground speed, then either shift to a lower gear, or move over and cut a thinner strip on these areas."

I'm coming to the conclusion the 6' wide rotary mower is too much for my 41 HP Kioti, given the hills, the height of the thick vegetation, the debris that chronically clogs up the screens (and seeps into the radiator cooling fins), the FEL (which I really want to keep on the tractor because of the hills), and the hydrostatic transmission, which I always run in LOW and with 4 wheel drive (another load on the tractor).

Thanks for posting!

Rhino