2006 M9540 Overheating

[Glocknstihl]

I work with my uncle doing commercial landscaping, and a big part of it is mowing the highway medians for the city. We have to use flail mowers because the contract says no rotary mowers. The big Kubota has been overheating, the AC shuts down, and turns the cab into an oven. I dont personally drive that tractor, but I'd like to solve the problem because parking it for an hour is a big time killer.

I forget the actual hours, but I believe it's in the 20k range. New thermostat, changed coolant, and we regularly use a leaf blower to clean under the hood and the radiator find. The fella who drives it, even added an electric fan in front of the radiator and it made no difference what so ever. I'm thinking the water pump is worn out and just not moving water like it should. But since I'm not a Kubota expert, I want to ask you that are. I'm a huge Kubota fan though. I have a 2005 M5700 with 230 hours on it, and a 2017 RTV1100.

So, is there something else I should try?

 

[SidecarFlip]

Take a pressure washer and clean the radiator (after removing the screens).

I take the roof off my cab every year and blow out the AC plus I added layer of Reflectix foil-bubble-foil under the roof and over the ac unit.

Mine will freeze you out and the temp gauge never gets over halfway up. If the water pump was shot, it would be leaking out the front weep hole.

I clean mine every day when I'm running hay and I mean every day.

 

[SRG]

It's overheating, or the AC shuts down, or both? If the machine is overheating, it's possible to develop a warped head, which will cause coolant leaks, and burning of coolant in the combustion chamber.
Have you tested the coolant to see if it is with in spec? You can get coolant test kits at auto parts stores. Old coolant looses its ability to cool over time.
You're gonna need to provide more info.
When was the last time the coolant system was flushed and changed?
Is the overflow checked regularly for a consistent level?
Any recent maintenance done?
Any white smoke in the exhaust?
Change/cleaned cabin filters?

Does Kubota use thermostats, or restrictors in these?
Is the water pump impellar, plastic or metal? Things do wear out. Sounds like a lot of hours, to where parts might start needing to be replaced too.

If the coolant level is consistently full, and you aren't noticing usage or leaks, first thing I'd do is test the coolant for its cooling capabilities.

 

[D2Cat]

Get an infrared heat gun and actually check the temps at the upper and lower radiator hoses. Also check at the back of the engine on the head. There should be about a 40 deg differential between the upper and lower radiator hoses. The back of the block should read about the same as your gauge in the cab. Then you will know how hot it is actually getting.

 

[Glocknstihl]

It's overheating, or the AC shuts down, or both? If the machine is overheating, it's possible to develop a warped head, which will cause coolant leaks, and burning of coolant in the combustion chamber.
Have you tested the coolant to see if it is with in spec? You can get coolant test kits at auto parts stores. Old coolant looses its ability to cool over time.
You're gonna need to provide more info.
When was the last time the coolant system was flushed and changed?
Is the overflow checked regularly for a consistent level?
Any recent maintenance done?
Any white smoke in the exhaust?
Change/cleaned cabin filters?

Does Kubota use thermostats, or restrictors in these?
Is the water pump impellar, plastic or metal? Things do wear out. Sounds like a lot of hours, to where parts might start needing to be replaced too.

If the coolant level is consistently full, and you aren't noticing usage or leaks, first thing I'd do is test the coolant for its cooling capabilities.

Coolant was changed at the end of last season, before the cold set in. No smoke, no coolant going anywhere, and it runs great. As far as I know he has never cleaned the cabin filters, but what does that have to do with the engine overheating? When it gets near the red on the gauge, the AC shuts off too.

It's hard to keep things clean as dry as it is right now. I run a 375 Massey and it never even reaches the middle of its gauge, and today it was 99 in the median. As I said, we do blow it off with a leaf blower. But never tried water.

I'm thankful for all the ideas. Can I use the car wash to spray it out? Will it not bend the fine?

I have a temp gun, I will check it tomorrow and post my findings.

Thanks to all of you.

 

[mattwithcats]

That looks like a 3/4-16 oil filter...

Instead of the HH1C0-32430, which is three and a half long, take a look at Wix 51515, (5 inches), or even longer, 51773 (7 inches).

RockAuto has good prices on Wix filters...

Sounds like the impeller on the water pump is not working...

What coolant and percentage did you use?

What oil and weight did you use?

 

[200mph]

Things I'd check considering coolant is maintaining its level over time.

1. Ensure radiator, condenser and associated screens are clean. Be careful not to bend the fins or other damage. Radiator and condenser are very expensive. (Radiator almost $1,000)

2. Verify the fan belt is tight and not slipping.

3. Verify the thermostat is opening or perhaps just replace it.

4. Verify the water pump is pumping coolant. At a minimum verify the water pump will rotate by hand (bearings not seized), but the pump impeller could still be detached preventing it from pumping coolant.

 

[SidecarFlip]

Little tractors for residential use and big ones are 2 different animals. His (and mine) not only have radiators, they have air to air charge air coolers that disrupt the airflow through the radiator which makes cleaning even more imperative. I'd be willing to bet the radiator is loaded with fine chaff in between the cooling fins. and the only way to remove it efficiently is a low pressure pressure wash from the backside (fan side) toward the front and then from the front (grille side) toward the engine.

The expansion valve on the ac will shut it down if the condenser freezes, how it works. I clean my cabin filter at least every week (I have 2, one in the roof and one on the bench, cleaned and drying) Again, it's also imperative to remove the roof and blow out the ac components under it, they will get loaded with dust and debris no matter how good your cabin air filter is. Once the condenser ices up, they no long blow cold are and then they shut down, that is a safety feature so you don't destroy the compressor.

It's unnecesary to go to a larger oil filter, the sumps on the M series hold a large amount of oil (mine holds 11 quarts) and the oil cooler will stabilize the oil temp at the coolant temp anyway. Just run a compatible grade (API certification) of oil and change it on the service interval. Myself, I use 5-40 Rotella T6, but that choice is a personal one. I like to use the same oil in everything, makes inventorying oil easier and I get mine is 55's, it's less expensive per gallon that way.

I think with that many hours I would be changing the thermostat to a lower opening temp one and checking the end play on the water pump shaft but I doubt the pump is faulty anyway as it apparently has no leaks and the impellers on the pumps are cast iron, not plastic.

The engines are very durable and 20K hours is nothing so long as they are maintained.

Don't need no heat gun or bigger oil filter, just needs to have a good radiator cleaning, checking the belt tension and possible a new thermostat and as an optional service, the roof removal and cleaning of the AC components under it.

Rememeber I own 2 now but had 3 and they all required maintenance, especially radiator cleaning and under the roof cleaning and optionally, a layer of Reflectix glued to the roof, laid over the ac components to reflect the heat from the sun beating on the orange roof.

 

[Jim L.]

I'm thankful for all the ideas. Can I use the car wash to spray it out? Will it not bend the fine?

The car wash will most surely bend your fins. Only low pressure water will avoid damage.

My experience in tall grass, the radiator is plugged in the air side. Take out the radiator so that it can be cleaned with low pressure water through the fins and inspected through the fins. The time will be well spent, as now the machine has to be stopped, cooled, blown, and loss of production.

The air conditioner needs cleaning also, as Flip has pointed out. Both evaporator and condenser must have air flowing for the thing to work. Clogging will raise system pressures which is not good in the long run.

As D2CAT says, measure the temps. After you clean it up, you can compare the new temps.

 

[SidecarFlip]

The car wash will most surely bend your fins. Only low pressure water will avoid damage.

My experience in tall grass, the radiator is plugged in the air side. Take out the radiator so that it can be cleaned with low pressure water through the fins and inspected through the fins. The time will be well spent, as now the machine has to be stopped, cooled, blown, and loss of production.

The air conditioner needs cleaning also, as Flip has pointed out. Both evaporator and condenser must have air flowing for the thing to work. Clogging will raise system pressures which is not good in the long run.

As D2CAT says, measure the temps. After you clean it up, you can compare the new temps.

I have to say, I've never bent the fins on any of my Kubota radiators and I use my 2100 psi gas pressure washer with a wide spray nozzle all the time. and a little bit of ZEP or Purple Power sprayed in the radiator a few minutes prior to spraying it out will greatly improve the cleaning action.

If you do bend the fins, you can buy a 'coil comb' at Lowes or Menards that will straighten them back out.

Owning 3 M's (right now 2). I'm almost 100% certain you have a loaded up radiator. leaf blowers don't work, only thing I use one for is blowing hay chaff off my bailers

Just be sure to wash it both ways. I realize it's hard to get in there between the fan and the shroud but it is doable, I do it all the time.

 

[SidecarFlip]

You see, Kubota uses the same capacity radiator for the non cab, no ac models as they do for the climate controlled ones so coolng becomes marginal with the added load of the ac condenser and the ATA unit pre heating the air before it gets to the radiator.

I also added a 12 volt permag fan in front of the AC unit blowing back through the rad. I have mine wired with a relay, into the compressor clutch circuit so the only time it runs is when the magnetic clutch is energized on the ac compressor. It helps but the real cure is a clean rad.

 

[mattwithcats]

Collapsed or pinched hose may be possible...

 

[SRG]

Collapsed or pinched hose may be possible...

That's another good one to watch out for. With that many hours, akin to 6 digit miles on a vehicle, rad hoses can become soft, and prone to collapse when at maximum or over max operating temp. Just something else to look out for.
Could be a myriad of possibilities.
Could be a stuck thermostat, collapsed hosed, impeller rusted it broke off, coolant not up to spec, dirty radiator, leaking coolant, burning coolant, not enough coolant, bad radiator cap, air bubbles trapped in the system.

 

[Glocknstihl]

Get an infrared heat gun and actually check the temps at the upper and lower radiator hoses. Also check at the back of the engine on the head. There should be about a 40 deg differential between the upper and lower radiator hoses. The back of the block should read about the same as your gauge in the cab. Then you will know how hot it is actually getting.

Top hose was 206° and the bottom hose was 187°.

 

[SidecarFlip]

Told you what the cause was and what to do about it.. Either heed my advise (remember I have 2 of them) or not. Anyway, I'm done posting on this thread. Stuff people are listing may apply but probably don't.

Have fun....

 

[Glocknstihl]

I have to say, I've never bent the fins on any of my Kubota radiators and I use my 2100 psi gas pressure washer with a wide spray nozzle all the time. and a little bit of ZEP or Purple Power sprayed in the radiator a few minutes prior to spraying it out will greatly improve the cleaning action.

If you do bend the fins, you can buy a 'coil comb' at Lowes or Menards that will straighten them back out.

Owning 3 M's (right now 2). I'm almost 100% certain you have a loaded up radiator. leaf blowers don't work, only thing I use one for is blowing hay chaff off my bailers

Just be sure to wash it both ways. I realize it's hard to get in there between the fan and the shroud but it is doable, I do it all the time.

We finished this months mowing today. We are going to wash the radiator out, and flush the system.

 

[12251hd]

I have an 06 M6800 that I use primarily for bush hogging. It too, will tend to overheat if I don't keep the radiator clean. Recommend you only use your compressor air to blow out the radiator. Especially get down at the hard to reach bottom. Recommend you never-never use water to clean out the radiator as the grass/weed seeds will expand and further clog the air flow. I'm told these models are known for the problems of debris clogged radiators--clean it often. Good luck.

 

[D2Cat]

Here's a good tool to assist in actually getting the radiator clean. Soak with Simple Green, or similar, cleaner for a few minutes then wash off.

https://www.ebay.com/itm/Radiator-G...899818?hash=item285de3c42a:g:18EAAOSwCx5bK0A9

 

[Glocknstihl]

Here's a good tool to assist in actually getting the radiator clean. Soak with Simple Green, or similar, cleaner for a few minutes then wash off.

https://www.ebay.com/itm/Radiator-G...899818?hash=item285de3c42a:g:18EAAOSwCx5bK0A9

I sent him that picture. These tractors only ever do mowing of some sort. From small flails, to batwing bushhogs.

 

[SidecarFlip]

Said I wouldn't comment any more but I do have this to say. I wish Kubota used a reverse flow cooling fan like JD uses on the ag tractors You can reverse the flow from in the cab and blow out the crap with the cooling fan. A couple times a day does the trick.