Kubota's with Roof Mounted A/C system

Jms63

Member

Equipment
Mx6000
Oct 17, 2021
51
17
8
Alabama
Before adding an auxiliary fan check everything for cleanness. Use lights and mirrors if neccessary to see between radiator,grill,screen,coils and such. Check between fins for dirt and duff. While engine is at ambient temperture backwash coils with garden hose. Don't use any kind of coil cleaner unless you are absolutly certain the chemicals are intended for EXACTLY what you are doing. Many coils are ruined every summer using improper cleaners and or improperly using cleaners. Dish washing soap is all you need and there's no way it can harm anything. Don't overlook coils in evaporator and evaporator fan blades. If either are dirty performance will suffer. Heed what someone said about installing a manual valve to stop coolant flow through heater coils. Make certain someone hasn't removed fan shroud,it plays a big roll in engine cooling. See if coolant fan has thermostatic control and if so it's working. If you add a fan make certain it doesn't block as much air as it adds. I would opt for heavier coolant fan blade rather than trying to boost flow with an electric fan.
Can you actually buy a engine cooling fan blade that will pull more air, have you seen this modification?
 

Fedup

Active member
Apr 6, 2016
204
53
28
Winchester
Can you actually buy a engine cooling fan blade that will pull more air, have you seen this modification?
Moving more air is not always a solution. The fan is probably drawing plenty of air, it's a matter of where that air flows. The condenser is often out front and some distance from the radiator and other coolers, so much of the air flowing goes around the condenser rather than through it. Adding the electric fan to the condenser itself insures that its output goes directly into and past the fins with maximum effect.
 
  • Like
Reactions: 1 user

jaxs

Active member

Equipment
B1750HST
Jun 22, 2023
395
178
43
Texas
Can you actually buy a engine cooling fan blade that will pull more air, have you seen this modification?
The blades aren't off the shelf items at parts store but special order from radiator specialty shops. The demand is for use on automobiles but they can build one for anything if given specs. I would only install an auxiliary fan of any kind as last resort after making sure everything else is right.
 
  • Like
Reactions: 1 user

Jms63

Member

Equipment
Mx6000
Oct 17, 2021
51
17
8
Alabama
The blades aren't off the shelf items at parts store but special order from radiator specialty shops. The demand is for use on automobiles but they can build one for anything if given specs. I would only install an auxiliary fan of any kind as last resort after making sure everything else is right.
I have actually taken the cap off the cab and insulated the underside with reflectix and R19 insulation was told this would help a good bit… my air works pretty well but with these temps we been getting in central Alabama lately it just wasn’t doing what it should …still cool enough to operate but not actually cold… I’m think the insulation might get me where I want to be
 

jaxs

Active member

Equipment
B1750HST
Jun 22, 2023
395
178
43
Texas
I've lost count of coils I've found dirty after owner assured me they routinely cleaned them. The watch word is "between coils" and ability to see light through coils. Something I failed mention along with coil cleaning is DO NOT put screen wire in front to catch debris before it reaches coil. Sounds good in theory and lots of people do it but I'm telling you don't.
 

Jms63

Member

Equipment
Mx6000
Oct 17, 2021
51
17
8
Alabama
I've lost count of coils I've found dirty after owner assured me they routinely cleaned them. The watch word is "between coils" and ability to see light through coils. Something I failed mention along with coil cleaning is DO NOT put screen wire in front to catch debris before it reaches coil. Sounds good in theory and lots of people do it but I'm telling you don't.
My mx6000 came with a small screen hanging in front of the front coil between the battery and the coil has 2 eyelets I. The screen that hangs in front of coil
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
4,807
1,575
113
Mid, South, USA
Moving more air is not always a solution. The fan is probably drawing plenty of air, it's a matter of where that air flows. The condenser is often out front and some distance from the radiator and other coolers, so much of the air flowing goes around the condenser rather than through it. Adding the electric fan to the condenser itself insures that its output goes directly into and past the fins with maximum effect.
Most of them have sealing foam that fits around the outside of the cores, which then is in contact with the hood as the hood is "down", causing air to be pulled past all of the cores. Intercooler (if it has one, most don't), a/c condenser, radiator, oil cooler, fuel cooler, etc. While on this subject, have to be mindful of where the air goes. After it's pulled through the cores, it's got to be forced out the back. So some bonnets (hoods) will have vents along them, and those vents also need to be clear to let the hot air out. allowing them to get dirty/plugged/restricted can hurt the performance of the cooler cores. Belts also need to be tight, slipping a/c belt is a big cause of poor a/c on cab tractors.

Have to be careful with aux E-fans. The factory engine-mounted fan pulls a TON of air, so much that sometimes an aux E-fan can become a restriction.
 

Fedup

Active member
Apr 6, 2016
204
53
28
Winchester
Most of them have sealing foam that fits around the outside of the cores, which then is in contact with the hood as the hood is "down", causing air to be pulled past all of the cores. Intercooler (if it has one, most don't), a/c condenser, radiator, oil cooler, fuel cooler, etc. While on this subject, have to be mindful of where the air goes. After it's pulled through the cores, it's got to be forced out the back. So some bonnets (hoods) will have vents along them, and those vents also need to be clear to let the hot air out. allowing them to get dirty/plugged/restricted can hurt the performance of the cooler cores. Belts also need to be tight, slipping a/c belt is a big cause of poor a/c on cab tractors.

Have to be careful with aux E-fans. The factory engine-mounted fan pulls a TON of air, so much that sometimes an aux E-fan can become a restriction.
I don't see a lot of foam on the tractors I work on. When I see the high pressure exceed 350 PSI (with the hood open or closed), what I consider an undersized condenser six inches or more away from the nearest cooler, and a battery in front of it, I start thinking some extra airflow might help. If/when it doesn't then we try something else. I've yet to mount one that I felt was a hindrance.
 

Jms63

Member

Equipment
Mx6000
Oct 17, 2021
51
17
8
Alabama
Most of them have sealing foam that fits around the outside of the cores, which then is in contact with the hood as the hood is "down", causing air to be pulled past all of the cores. Intercooler (if it has one, most don't), a/c condenser, radiator, oil cooler, fuel cooler, etc. While on this subject, have to be mindful of where the air goes. After it's pulled through the cores, it's got to be forced out the back. So some bonnets (hoods) will have vents along them, and those vents also need to be clear to let the hot air out. allowing them to get dirty/plugged/restricted can hurt the performance of the cooler cores. Belts also need to be tight, slipping a/c belt is a big cause of poor a/c on cab tractors.

Have to be careful with aux E-fans. The factory engine-mounted fan pulls a TON of air, so much that sometimes an aux E-fan can become a restriction.
You know I was thinking about putting some kind of insulation on each side of the condenser and between the front radiator and and such just to force that air to come in through all the coils…. Does seem like with the way they have that designed a lot of air is coming in around the coils…. I might try that too… prolly need to be mindful of the water temp though just to make sure it getting enough air… prolly leave the top of the hood at the radiator open so it can pull extra air from there
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
4,807
1,575
113
Mid, South, USA
You know I was thinking about putting some kind of insulation on each side of the condenser and between the front radiator and and such just to force that air to come in through all the coils…. Does seem like with the way they have that designed a lot of air is coming in around the coils…. I might try that too… prolly need to be mindful of the water temp though just to make sure it getting enough air… prolly leave the top of the hood at the radiator open so it can pull extra air from there

raise the hood on an M series, look at the bottom of the hood. They put self-stick foam on the hood, so when you close it, the foam contacts the top of the radiator. There's usually also some along the sides of the hood and on some of em there's foam around the cores themselves (radiator usually). Kubota uses different terminlogy for the foam, some tractors they call them pads others they call them tape, others who knows. Jinglish. One you learn Jinglish, you'll better understand "Kubota". Every tech that came into our shop, during the first week or so we'd be talking about different stuff and I'd try to burn into their brains about "Jinglish". A few of them listened. Others just laughed. One of them I remember well, he had an issue with a standard L that wouldn't start. He asked my my thoughts, I told him you might look at the delay reray (that's what the book calls it). Sure enough, ordered a new delay reray and it solved the issue. Bad part is, on the r/o, he keyed it in as such "Replaced reray". Part description was also exactly that "delay reray). Customer was thrilled about that.

Have had some MX's show up that would run hotter than normal, all the foam missing off of the hood. Put it back on, heating issues resolved. Damaged hoods were an issue as well in that sense. They wont' seal very well around the cores.

my car has some plastic baffling around the outside of the IC and the radiator of course part of that reason is airflow due to forward travel. Tractors don't have a fast enough forward travel to generate enough airflow to make any difference, so the fan does all the work.
 
  • Like
Reactions: 1 user

Jms63

Member

Equipment
Mx6000
Oct 17, 2021
51
17
8
Alabama
raise the hood on an M series, look at the bottom of the hood. They put self-stick foam on the hood, so when you close it, the foam contacts the top of the radiator. There's usually also some along the sides of the hood and on some of em there's foam around the cores themselves (radiator usually). Kubota uses different terminlogy for the foam, some tractors they call them pads others they call them tape, others who knows. Jinglish. One you learn Jinglish, you'll better understand "Kubota". Every tech that came into our shop, during the first week or so we'd be talking about different stuff and I'd try to burn into their brains about "Jinglish". A few of them listened. Others just laughed. One of them I remember well, he had an issue with a standard L that wouldn't start. He asked my my thoughts, I told him you might look at the delay reray (that's what the book calls it). Sure enough, ordered a new delay reray and it solved the issue. Bad part is, on the r/o, he keyed it in as such "Replaced reray". Part description was also exactly that "delay reray). Customer was thrilled about that.

Have had some MX's show up that would run hotter than normal, all the foam missing off of the hood. Put it back on, heating issues resolved. Damaged hoods were an issue as well in that sense. They wont' seal very well around the cores.

my car has some plastic baffling around the outside of the IC and the radiator of course part of that reason is airflow due to forward travel. Tractors don't have a fast enough forward travel to generate enough airflow to make any difference, so the fan does all the work.
You know I haven’t even looked to see if my hood has it I will check that out before adding any… I really believe that insulating the roof is going to get me where I want to be in Alabama heat, we usually only have 4weeks a year that extremely hot in that 95-100 range
 

jaxs

Active member

Equipment
B1750HST
Jun 22, 2023
395
178
43
Texas
You know I haven’t even looked to see if my hood has it I will check that out before adding any… I really believe that insulating the roof is going to get me where I want to be in Alabama heat, we usually only have 4weeks a year that extremely hot in that 95-100 range
4 weeks 96-100 range is also about all we get in Texas,,,,,,,,,,it's usually 101-107 the rest of Summer. 🤒
 

Hunter1157

Member

Equipment
MX 6000 HST Cab, Kubota RTV X1140
Apr 26, 2020
31
21
8
Palestine, Tx.
jaxs, I am interested in this statement you made earlier. My MX has a flimsy screen in front of the AC condenser/coil that doesn't even cover 2/3's of it. I feel it is more of a hinderance than a help. I flush all the coils and radiator after each use. So I would assume removing that screen would help air flow.

Something I failed mention along with coil cleaning is DO NOT put screen wire in front to catch debris before it reaches coil. Sounds good in theory and lots of people do it but I'm telling you don't.