Overheating diagnosis

JRaf

Member

Equipment
L245DT
Oct 15, 2019
55
6
8
Los Olivos CA
I have an old L245DT and it's overheating after a couple of hours of bush hogging. I feel pretty stupid but I'm not exactly sure how the system works or what I should be looking for. I flushed the radiator and filled it with coolant. I changed out the thermostat. When it overheats all the coolant is gone. (Does that mean the water pump is working?) There's no coolant in the oil and I get off it pretty quickly when it starts getting hot. Radiator fan is turning. There's no temp gauge on this tractor though maybe that should be my next project. Radiator and plumbing are not leaking. Today I'll pull the radiator and blow it out. What else should I be looking at? Do I assume the water pump is not working or working intermittently?
 

TheOldHokie

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I have an old L245DT and it's overheating after a couple of hours of bush hogging. I feel pretty stupid but I'm not exactly sure how the system works or what I should be looking for. I flushed the radiator and filled it with coolant. I changed out the thermostat. When it overheats all the coolant is gone. (Does that mean the water pump is working?) There's no coolant in the oil and I get off it pretty quickly when it starts getting hot. Radiator fan is turning. There's no temp gauge on this tractor though maybe that should be my next project. Radiator and plumbing are not leaking. Today I'll pull the radiator and blow it out. What else should I be looking at? Do I assume the water pump is not working or working intermittently?
Sounds like a coolant leak to me. If it aint external then .....

Dan
 

Rouseslane

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Equipment
G2160
Jun 29, 2024
1
1
3
Uk
I have the same issue with my old Kubota G2160 ride on mower.
Run fine for about 30 minutes then blows all coolant out of expansion bottle hoze.
I have replaced radiator, thermostat and flushed new coolant. I also changed oil and there is no milky residue.
Someone told me the next likely culprit is the head gasket which is causing a build up of pressure.
Is this the considered opinion of others ?
 
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X-Pup

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Equipment
L2501, 526 Loader W/QC LP RCF2060 Cutter, BB 1260-82, 3RD Function, top&Tilt
Nov 13, 2022
27
22
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Washington
If it is a head gasket, you certainly don't want to keep running it that way. Water does bad things to internals.

Any white smoke from the exhaust?
 
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JRaf

Member

Equipment
L245DT
Oct 15, 2019
55
6
8
Los Olivos CA
I pulled the hoses (which are a little spongey, though no obvious leaks when cold) and the radiator. There was about another quart and a half of liquid in the block and the bottom of the radiator. No oil or gas in there. The screen and the veins on rad were somewhat muddy and blocked. I blew it all out and will soak the radiator in vinegar but there's no blockage inside. I'll order new hoses and clamps, flush the whole thing and see how it goes. I'm thinking there's a leak in the hoses or the radiator that isn't obvious until there's some pressure.
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
5,426
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Austin, Texas
You may have a cracked head. These older engines are prone to cracking the head when overheated.

But you can verify that later if needed. Often it is the external side of the radiator that is clogged with grass and dirt. There should be a fine mesh screen in front of the radiator. That can also be blocked by chaff, especially when mowing tall grass with seed heads. I put a blue air filter (cheap disposable) in front of the screen to help catch seed that catch in the mesh and that has made it much easier to keep the screen and radiator clean.

Also the battery may be mounted in front of the radiator and block airflow.

You seem to be able to run for some time without overheating so I don’t think you need to worry about the head yet. Just get the inside and outside of the radiator clean. Then you can see if the water pump is moving water through the system by leaving the radiator cap off and getting the engine up to temperature and looking for flow through the radiator. I would recommend that you also replace the radiator cap with a new one with the correct pressure rating. Maybe buy from the dealer if they don’t want too much money for it.

There may be a place to connect a temperature gauge but the tractor came with a whistle on the end of the radiator overflow hose. It may still be there or you may need to get a replacement one.

Keep repairing the radiator and see what happens then move on to thermostat and water pump if it doesn’t work properly after the radiator cleaning.
 
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Edke6bnl

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B7800 Kubota, case 1840 Skidsteer Ford 3500
Mar 31, 2022
230
119
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Agua Dulce, California
MADDOX COMBUSTION Tester about $30 will let you test if the are combustion gas in the radiator. For leaks I would use a rad presuure Tester and set at rad cap psi and watch for leaks.
 
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JRaf

Member

Equipment
L245DT
Oct 15, 2019
55
6
8
Los Olivos CA
Thanks so much! The whistle's still there but I can't hear it with my ear protection on. This thing is LOUD. The radiator cap could be original, no idea. I'll try and figure that out.
And yeah, the screen is there and it does get clogged up and the battery sits right in front of that which makes no sense. I already have a secondary battery mounted on the loader frame. I could just move a bigger single battery down there and let the radiator breath a little better.
There's no temperature sensor anywhere on the engine that I can find but I've seen sensors that you can mount on the hose inlets. I guess the top hose would be the right spot. I'll look into that.
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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See if you have this port first

see a diagram here

 

Ktrim

Well-known member

Equipment
B2400, lA352 loader,3pth quick hitch/z122r zero turn/restored 52 farmall super a
Dec 23, 2020
431
354
63
Nazareth Pa
Could be rad cap. Pressure raises the boiling point of coolant. If you don't have pressure it will overheat.
Most auto parts stores will rent rad pressure testers. It should have an adapter to also check the cap
 

D2Cat

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When you clean the radiator spray the fins with a cleaner (purple power) and let it soak for 10 minutes or so, then rinse off. This will remove the fine build up that reduces efficiency of the radiator.
 
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JRaf

Member

Equipment
L245DT
Oct 15, 2019
55
6
8
Los Olivos CA
Just for the record, I pulled the radiator and flushed the system,. That seemed to help but the engine still got hot enough to blow the whistle after a hot hour and a half of hard work. I ordered new hoses, a rad cap, and a new thermostat. I only got the cap installed, and but that seemed to do it. It ran much cooler and never bogged down. (I'm in California, we had record rain last year and I've been bush hogging a LOT).
 

Henro

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May 24, 2019
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Does the L245DT have a water pump?

For some reason, I got the feeling it might be one of the thermosiphon type Kubota tractors without a water pump.

just a gut feeling that I have for some reason and I don’t know, and I don’t know where to check either…

edit: got curious and looked at the workshop manual at Kubota books and I guess it’s the old L185 that doesn’t have the water pump… The L245 apparently does have one. So I could’ve answered my own question without posting here! Oh well… the damage is done! :ROFLMAO:
 
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JRaf

Member

Equipment
L245DT
Oct 15, 2019
55
6
8
Los Olivos CA
So I've replaced the hoses, thermostat, rad cap, and flushed the system pretty vigorously. I'm not overheating anymore but I am getting a leak around these little circular caps on the left side engine block near the starter and oil temp sensor (see pic). Can I repair these? Pry them out and shove new ones in there? Or just pretend they're not a problem...?
 

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Ktrim

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B2400, lA352 loader,3pth quick hitch/z122r zero turn/restored 52 farmall super a
Dec 23, 2020
431
354
63
Nazareth Pa
Freeze out plug. Yeah you can change it out but you're going to loose all coolant out of the block you just put in. I have seen them reseal after a few heat cool cycles.
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
5,426
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Don’t drill through them, you can damage the cylinder wall behind them.

Or so I have seen people posting about the damage.
 
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#40Fan

Active member
Jul 21, 2022
295
171
43
USA
Those freeze plugs are shot. Probably from running with just straight water.

YouTube (<<--verb) videos on removing those. What you want to do is hit them gently with a punch, at the top/inner portion which will cause them to spin in the hole. Once they have spun just a little, grab them with pliers and pull them out. Not a big deal if you knock one into the block. They usually don't go far and can be grabbed with needle nose pliers.

Installing new ones (after going to parts store and matching up the size) is easy too. Clean up the surface to remove rust and dirt, then drive the new ones in keeping them square to the hole.
 
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