M7040 A/C doesn’t blow hard

Ruskyhog

New member
Jan 2, 2018
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Wills Point, Texas
I have a M7040 4x4 (unsure on exact year) that has 1100 hours and the A/C doesn’t blow hard at all. The air is extremely cold though. I’ve thoroughly cleaned all the filters, radiator, a/c coils etc. I have to keep all but one or two closed, if I open them all you can still feel the air coming out cold but even with your hand on top of the vent opening you can barely fee air moving. I have thought it was just a normal deal for that model until I sat in a friends the other day and the difference is night & day. His lowest level fan speed blows harder than mine on full blast. What am I missing? Any help is greatly appreciated!!

Thanks
Josh


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Tughill Tom

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Equipment
B3200
Dec 23, 2013
1,102
1,116
113
Turin, NY
I have a M7040 4x4 (unsure on exact year) that has 1100 hours and the A/C doesn’t blow hard at all. The air is extremely cold though. I’ve thoroughly cleaned all the filters, radiator, a/c coils etc. I have to keep all but one or two closed, if I open them all you can still feel the air coming out cold but even with your hand on top of the vent opening you can barely fee air moving. I have thought it was just a normal deal for that model until I sat in a friends the other day and the difference is night & day. His lowest level fan speed blows harder than mine on full blast. What am I missing? Any help is greatly appreciated!!

Thanks
Josh

You may need to have to clean the blower fan wheel. It could be loaded with dirt, chafe.
 

Ruskyhog

New member
Jan 2, 2018
26
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0
Wills Point, Texas
I have a M7040 4x4 (unsure on exact year) that has 1100 hours and the A/C doesn’t blow hard at all. The air is extremely cold though. I’ve thoroughly cleaned all the filters, radiator, a/c coils etc. I have to keep all but one or two closed, if I open them all you can still feel the air coming out cold but even with your hand on top of the vent opening you can barely fee air moving. I have thought it was just a normal deal for that model until I sat in a friends the other day and the difference is night & day. His lowest level fan speed blows harder than mine on full blast. What am I missing? Any help is greatly appreciated!!



Thanks

Josh



You may need to have to clean the blower fan wheel. It could be loaded with dirt, chafe.


Where is that located?


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SidecarFlip

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M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
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Take the top off the cab and clean the innards with compressed and then install some Reflectix foil-bubble-foil (you can get a roll at Lowes or Home Depot on the underside of the top. Stick it on with 3M contact spray adhesive. You have a load of crap in your ac and heat system. probably from an ill sealing outside air filter (the one on the side of the top). I run mine on Recirc most of the time btw.

The Reflectix will reflect the sun's heat off the lid and make your AC work even better.
 

Jim L.

Active member
Jun 18, 2014
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Texas
Best thing to do now is to download an M7040 Workshop Manual from kubotabooks.

Answers are in the air conditioning section.

Blower motor
Blower resistor
Blower relay
Blower high relay
Clogged filter
Blower interference
Blower duct clogged

Good news is that it is blowing cold, so please don't open any refrigerant fittings.
 

Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
5,107
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Williamstown Ontario Canada
There is nothing in the ceiling of an M7040. It is all below the seat including the fan.

There are two air filters, one under the edge of the roof on the drivers side and a second beside the drivers seat.

Make certain both are clean before removing the seat.

Next check the blower high speed relay inside the AC compartment under the seat.

Dave
 

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SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
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There is nothing in the ceiling of an M7040. It is all below the seat including the fan.

There are two air filters, one under the edge of the roof on the drivers side and a second beside the drivers seat.

Make certain both are clean before removing the seat.

Next check the blower high speed relay inside the AC compartment under the seat.

Dave
Depends on the year. He said he didn't know the year. But with 1100 hours on it, I suspect it's more than 2 years old.The new ones as of 2 years ago are under the seat, the older ones are in the roof panel.

Nothing wrong with the blower except it's loaded with crud.

I ought to know, I have one...

Glad mine isn't under the seat, the seat is a PITA to remove as it is.
 
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Tx Jim

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M7040 HDC-1,JD 4255,Ford 6700
Apr 30, 2013
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Coyote Flats,Texas
Mine is a 2012 and the AC is under the seat

Dave
My '11 M7040 has AC evaporater/blower under the seat also. My cab blower blows hard when set on high speed. I wonder if mode switch is set on a setting other than dashboard outlets?? Has OP checked/cleaned both inside & outside cab air filters? I wonder if outside filter is installed in correct orientation with large opening aimed to the outside of cab?
 

lugbolt

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ZG127S-54
Oct 15, 2015
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Mid, South, USA
First, check the filters and air intake screens.

If those are OK, remove the seat, and the plate that the seat is bolted to. You may find the seat plate cracked, and that would not be uncommon either. Weld it up or just replace it. I think it's about $125, IIRC. Then remove the screws that hold the top of the heater box to the bottom of the box (philips head screws IIRC). At that point, you can access the fan, the evaporator, and heater cores. It's likely that you'll find your heater core and/or evaporator core at least partially plugged, which isn't uncommon. You have to be really careful, but the evaporator can be removed with the lines attached, just far enough to get it over out of the way so you can get good access to both sides of it; and you'll want access to both sides. When you open up the box, you'll see one side-and it looks clean, once you pull it out of the box you can see the dirty side a lot better. For cleaner, I like to use a good coil cleaner-it's specifially made for the purpose and will remove 99% of the dirt, grime, mold, dog hair, back hair, and whatever else might be stuck to it. If the operator is a smoker, the core(s) will be brown, the tar makes all kinds of stuff stick to it. While you're in there, wipe out the box as best you can; and I like to remove the floor mat and insulation and clean those as well. To clean the foam insulation, spray it down with your favorite cleaner, then rinse it clean--but then hang it up to dry, in the sun with some wind works pretty good and takes a couple days to fully dry. While that's drying out, you can wipe down the interior, clean the exterior and make it like new again. Sure makes your tractor feel more like a new one. Take good care of 'er, they don't make them like that no more.
 

BAP

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2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
Dec 31, 2012
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First, check the filters and air intake screens.

If those are OK, remove the seat, and the plate that the seat is bolted to. You may find the seat plate cracked, and that would not be uncommon either. Weld it up or just replace it. I think it's about $125, IIRC. Then remove the screws that hold the top of the heater box to the bottom of the box (philips head screws IIRC). At that point, you can access the fan, the evaporator, and heater cores. It's likely that you'll find your heater core and/or evaporator core at least partially plugged, which isn't uncommon. You have to be really careful, but the evaporator can be removed with the lines attached, just far enough to get it over out of the way so you can get good access to both sides of it; and you'll want access to both sides. When you open up the box, you'll see one side-and it looks clean, once you pull it out of the box you can see the dirty side a lot better. For cleaner, I like to use a good coil cleaner-it's specifially made for the purpose and will remove 99% of the dirt, grime, mold, dog hair, back hair, and whatever else might be stuck to it. If the operator is a smoker, the core(s) will be brown, the tar makes all kinds of stuff stick to it. While you're in there, wipe out the box as best you can; and I like to remove the floor mat and insulation and clean those as well. To clean the foam insulation, spray it down with your favorite cleaner, then rinse it clean--but then hang it up to dry, in the sun with some wind works pretty good and takes a couple days to fully dry. While that's drying out, you can wipe down the interior, clean the exterior and make it like new again. Sure makes your tractor feel more like a new one. Take good care of 'er, they don't make them like that no more.
Well written Lugbolt. I have seen many tractor AC units that look clean but they will have a layer of crap on the surface of coils between the heater coil and evaporator blocking air flow. The only way to find it is to take it apart
 

Ruskyhog

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Jan 2, 2018
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Wills Point, Texas
Well pulled the seat, floor pan, seat pan and the plastics. Lots of dirt!!! Vacuumed and blew all the everything out with a air hose. It definitely blows harder than before. I let it sit outside and just run for a bit and noticed I wasn’t dripping any condensation from the A/C. I tried to find where it could be but no luck. Anyone have any idea where they are? I know I was probably overlooking it.

Thanks


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Tx Jim

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M7040 HDC-1,JD 4255,Ford 6700
Apr 30, 2013
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Coyote Flats,Texas
I'm glad you determined that evaporator was clogged. Have you viewed Kubota parts online to see if you can determine generally where drain hoses are located?
 

Ruskyhog

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Jan 2, 2018
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Wills Point, Texas
Update:
Found the drip line for the A/C. It was pretty dirty and clogged. I cleaned it by running a coat hanger up the tube and prayed water up the tub with a water hose. But still it seems like something else could be wrong because I can’t get any water to flow out of it after it has been running during the heat of the day. Anyone else have any any further ideas?


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Tx Jim

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M7040 HDC-1,JD 4255,Ford 6700
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You could try blowing short bursts of compressed air into the drain hose. If AC evaporater isn't freezing up I probably wouldn't worry with the hose.
 

BAP

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If the line was plugged, then the drip pan under the AC is probably full of crap. When you blow up the line, it clears out of the way, but then floats back over the hole blocking it off.
 

Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
5,107
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When you asked bout the drain line, I crawled under my M7040 expecting to see condensate but I could not even see a drain. Everything seemed to be on top of the transmission with no drain.

Does it come out the rear of the tractor?

Dave
 

Ruskyhog

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Jan 2, 2018
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Wills Point, Texas
Sorry for the delay.....

The line that I found (I’m assuming) was the drain line was on the left side at the back of the engine compartment close to the cab and came out just above where the loader frame attaches. Not sure if that was it or not though.


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