Kubota L2800 HST tractor running hot

[threeoaks]

While using my L2800 with a BushHog BH6 the temp gauge gets to the red within a few minutes of cutting.

Here is what I've done:

Replaced radiator.

Replaced fan belt and it is tight.

Replaced water pump.

Replaced thermostat.

Checked the oil and it is not milky and it is clean.

Tractor has 470hrs on it.

The BH6 Specs are 25HP.
L2800 tractor is 30 Engine HP.
The PTO is only 22.5 HP.

Is my issue that the BushHog cutter is too big for my tractor and no matter what I do it will always overheat when trying to use it?

 

[freewheel3]

Have you verified the accuracy of the gauge?

 

[Justasquid]

Have you inspected the brush hog itself to make sure its not binding and creating more drag? Have you checked the gear box on the brush hog?

 

[old and tired]

How heavy is the stuff you are cutting? What if you just drive around without cutting? 6 foot cutter is mighty big for our tractors...

 

[freewheel3]

I run a 6' Land pride behind my MX5000 with 50 horses. It runs it fine but in heavy going I wouldn't want too much less, maybe it is just too big for your tractor.

 

[GreensvilleJay]

re:
The BH6 Specs are 25HP.
L2800 tractor is 30 Engine HP.
The PTO is only 22.5 HP.

'by the numbers'...... the BH needs 3 more HP than your tractor can supply to the PTO.
As a spec, 25HP ...??? running at 540 RPM I assume, maybe in 6" grass ?? I don't know, but the BH mfr should say HOW it's being used...

What I don't know is how much HP the tractor needs to be driving. I think PTO HP is the HP that can be used while the tractor is stationary( think old belt driven threshers and such).
I find it unreasonable that the tractor only needs 6HP to be driven, even then, the engine has to running at full speed or (PTO speed on the cluster).
Maybe someone KNOWS how 'they ' arrive at the 'numbers' ?

Also a BH cutting 4" grass needs low HP , 12"grass and saplings .. a whole lot more !

 

[mattwithcats]

I think your going to need a bigger tractor...

But, an oversized filter may help. Oil cools a tractor

Double oversized Wix 51773 or NAPA 1773 holds at least a quart more, and is twice the size of the Kubota one (HH164-32430), 7 inches....

Part Details

https://www.napaonline.com/en/p/FIL1773

An oversized Wix X 51515XP / NAPA Platinum 41515 is a high flow version, and 5 inches long...

Part Details

https://www.napaonline.com/en/p/PFL41515

I suggest you prefill these before installing....

Also try using Shell Rotella T6 in either 15W-40, or 5W-40....

Fill the radiator overflow tank up to the "HOT' line when the tractor is cool...

 

[DustyRusty]

verify the engine temperature with a infrared heat gun. Gauges are known to go bad. Why would you replace a radiator, unless it were defective. Seems that you are throwing parts at the problem, but not verifying the cause of the perceived problem. Has the engine boiled over ever? When an engine gets the temp gauge into the red, you should keep the engine running, and attempt to cool it by idling at a high speed. Possible that what you are cutting is raising so much dust that the radiator is getting clogged causing it to not cool? Also a bad water pump can cause you problems, and even in the water pump is not leaking, the impeller at the inside of the pump might have become detached.

 

[DustyRusty]

I think your going to need a bigger tractor...

But, an oversized filter may help. Oil cools a tractor

Double oversized Wix 51773 or NAPA 1773 holds at least a quart more, and is twice the size of the Kubota one (HH164-32430), 7 inches....

Part Details

https://www.napaonline.com/en/p/FIL1773

An oversized Wix X 51515XP / NAPA Platinum 41515 is a high flow version, and 5 inches long...

Part Details

https://www.napaonline.com/en/p/PFL41515

I suggest you prefill these before installing....

Also try using Shell Rotella T6 in either 15W-40, or 5W-40....

Fill the radiator overflow tank up to the "HOT' line when the tractor is cool...

An oversized filter is only going to add to the capacity, but it will not help the cooling. He would need an oil cooler to dissipate the heat, and on a tractor, it would need something to move air across it. On an automobile, the transmission oil coolers are mounted where the movement of the vehicle can cool the oil, but on a tractor, it moves too slowly for a cooler to have much effect, without a fan blowing across the cooling fins.

 

[lugbolt]

on a cold engine take the radiator cap off. start the engine and look down into the radiator. Does it bubble? If so you either have a blowed head gasket or a cracked head-or both. Kubota cylinder heads are made of glass apparently. Overheat them, and they almost always crack.

99.99% of the time a cracked head doesn't let water into the oil or oil into the water, at least not on kubota's. Generally you just get combustion gases into the cooling system, which leads to overheating.

how's the fan? Shroud? How's the belt? Loose/slipping? Fan on backwards? Radiator screen? Plugged? Oil level ok? Proper dipstick for the engine? Air filter clean? No restriction in the air intake? What kind of fuel do you use? Possibility any gasoline, kerosene, jet fuel, water, lard, biodiesel, b10, rat piss, or anything else in the fuel? Anyone been into the engine at any point? Injection pump been off? Injectors been out? What's your valve clearance and has it been checked? At 470 hours it's not really time, even at 800 most of the time they're pretty close to spec....just throwing it out there, as something to ponder on.