M4D-071 problems

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
So the dealer replaced the loader valve and it seemed better at first but after using it with a grapple it is about the same again, also all 3 remotes on the back are leaking internally one of them let the rod move out 3/4" in about 8 minutes with a very light load, if I pull the cylinder in and disconnect the lines it held for over an hour, so the cylinder is good.This is my 1st Kubota and I was excited about buying it brand new but I dont think I will buy another Kubota.

Rex
 

SidecarFlip

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M9000HDCC3, M9000HD, Kubota GS850 Sidekick
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Not quite following the leaking remotes. Nothing to leak that I know of. All Pioneer style QD's will weep upon disconnect What rod? The actuator rod that ties to the linkage? There is a gland nut on the end. Might have worked loose.
 

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
Not quite following the leaking remotes. Nothing to leak that I know of. All Pioneer style QD's will weep upon disconnect What rod? The actuator rod that ties to the linkage? There is a gland nut on the end. Might have worked loose.
I have a sickle mower that has a hydraulic cylinder to raise and lower the cutter bar, if I raise the bar up all the way with the cylinder fully retracted, the cylinder moved out 3/4" in 8 minutes there are no external leaks that I can see. It seems to me that the remote valve is leaking by the spool. If the hoses are disconnected from the tractor it will hold all day.
 

SidecarFlip

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Sounds to me like some foreign matter in the seat area. Like I said, my FEL on my cab M9 has always dropped a bit but the open station don't. Never had any issues with the remotes however on either unit.
 

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
Sounds to me like some foreign matter in the seat area. Like I said, my FEL on my cab M9 has always dropped a bit but the open station don't. Never had any issues with the remotes however on either unit.
So the owner of the dealership came out to the farm today to check the hydraulic pressure, kubota claims that it has 2900psi but it tested at 1600psi, he thinks turning this up good be affecting the other issues that I have written about here. If you have a kubota you may want to check your hydraulic pressure, they had another customer with an m4 that tested at 1600psi plus 6 brand new on their yard tested at 1600psi, it's an easy fix just a simple adjustment of the relief valve but pretty shotty of kubota, that's not an accident.
 

SidecarFlip

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M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
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Actually, both of my M's are slightly above the WSM spec by a hundred PSI or so.
 

mbu

Member
Aug 28, 2016
260
4
18
United States
So the owner of the dealership came out to the farm today to check the hydraulic pressure, kubota claims that it has 2900psi but it tested at 1600psi, he thinks turning this up good be affecting the other issues that I have written about here. ...
Rexr,

Your tractor has a separate pump for the steering. Make sure its pressure meets specification too!

By the way, now that you have the tinted windows how would you rate its effectiveness in keeping the cab cooler?

Thanks...
 

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
Rexr,

Your tractor has a separate pump for the steering. Make sure its pressure meets specification too!

By the way, now that you have the tinted windows how would you rate its effectiveness in keeping the cab cooler?

Thanks...
I have talked to them about the separate steering pump and they seem to think that turning up the pressure on the lift side of the pump will help the steering too, my comment to them was if that fixes it I will be happy but I dont see how that will change the steering. They are going to check the pressure on the steering also and may have to turn it up as well.
The tint helps but this time of year it will not get the cab cold, as long as the air is blowing on you it is somewhat comfortable but still seems under sized to me, my neighbor has a newholland t4.75 and he keeps his fan on 2, I can not do that and stay comfortable, if I turn the fan on high it blows more air but the air doesn't seem as cold then but it is working within "specs"
 

mbu

Member
Aug 28, 2016
260
4
18
United States
Rexr,

Now that the hydraulic system pressure was set to Kubota’s specification, how is the tractor reacting?
 
Last edited:

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
Rexr,

Now that the hydraulic system pressure was set to Kubota’s specification, how is the tractor reacting?
They are suppose to pick it up monday and say it should be back in a couple of days. I will let you know how it turns out. Which tractor do you have?
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
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I have talked to them about the separate steering pump and they seem to think that turning up the pressure on the lift side of the pump will help the steering too, my comment to them was if that fixes it I will be happy but I dont see how that will change the steering. They are going to check the pressure on the steering also and may have to turn it up as well.
The tint helps but this time of year it will not get the cab cold, as long as the air is blowing on you it is somewhat comfortable but still seems under sized to me, my neighbor has a newholland t4.75 and he keeps his fan on 2, I can not do that and stay comfortable, if I turn the fan on high it blows more air but the air doesn't seem as cold then but it is working within "specs"
Even since I cleaned the ac HX's and had the tech come out and charge it up. Blower setting 1 is as cold as I can stand.
 

mbu

Member
Aug 28, 2016
260
4
18
United States
... Which tractor do you have?
I have a M760HDC18.

I think I mentioned this to you in a PM that I tested a MD-071 Cab like yours (wide radial tires in front) and it didn't have any of the troubles you mentioned in this thread. I tested the steering and with just the loader and two men standing in the bucket (I lifted them about 3-inches in the air) and I could drill holes in the hard ground by turning the front wheels back and forth from lock to lock. If I understand it correctly, the hydraulic steering circuit pressure should be around 1750 psi and around 2850 psi for the 3PH, FEL, and remote cylinders.

Incidentally, it sure seems odd that a certified Kubota mechanic would change out a hydraulic loader control valve and not check the the tractor's pressure before sending it back to you!
 

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
I have a M760HDC18.

I think I mentioned this to you in a PM that I tested a MD-071 Cab like yours (wide radial tires in front) and it didn't have any of the troubles you mentioned in this thread. I tested the steering and with just the loader and two men standing in the bucket (I lifted them about 3-inches in the air) and I could drill holes in the hard ground by turning the front wheels back and forth from lock to lock. If I understand it correctly, the hydraulic steering circuit pressure should be around 1750 psi and around 2850 psi for the 3PH, FEL, and remote cylinders.

Incidentally, it sure seems odd that a certified Kubota mechanic would change out a hydraulic loader control valve and not check the the tractor's pressure before sending it back to you!
I dont know, the loader valve was changed because the loader leaks down, to me that doesn't seem like a pump pressure issue but now they think it may be related after the loader continued to leak down with the 2nd valve. Maybe they will get lucky
 

lugbolt

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ZG127S-54
Oct 15, 2015
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Mid, South, USA
yeah "cold" a/c is subjective.

Case in point, certain Kubota I've had in the shop numerous times for "warm a/c" (that is the usual complaint on the r/o). Vent temps in the FORTIES, after running about 30 minutes. Obviously it's not going to get cold immediately. A lot of new cars have much more expensive and intricate a/c systems, e.g., variable displacement compressors, etc. They get cold quicker because of marketing. In other words, if one manufacturer says "my a/c gets cold faster than theirs", they have a marketing advantage. Anyway, back to my M series. After 3 or 4 times of checking it, I found nothing out of the ordinary other than the first time it had a plugged condenser (in between teh fins, not the screen--it was perfectly clean). I am honestly at that point dumbfounded, I mean I could get the cabin into the 70's really easily and it would maintain it. So finally instead of letting the service manager make the phone call to the customer, I called him myself from my personal phone, while inside the tractor, and told him get up here & see if this is acceptable. He shows up a couple hours later, hops in the tractor and goes to drive around. I had a hidden thermometer in the cab. He drives around for maybe 45 minutes and comes back & says nope still "hot". I grabbed my thermometer (which showed 78 degrees, and it was 98 outside) and showed it to him. He said that it's not acceptable. I asked why. He said he keeps his house a/c on 66 degrees. The cars (all climate control digital setting) set to 66-68 degrees. Well my God no wonder! Wuss. What tractor operator needs the a/c so cold that frost is forming on the windows? That's ignorant. As soon as you have to get out of the tractor you're blown away by heat, you're out in it for a few minutes, then you get back into that 68 degree cabin and you're spoiled.

20 degrees. That is the maximum temp drop that any a/c should reach. IOW, if it's 100 outside, figure that your air conditioner is going to struggle to get it below 80 inside. consider yourself lucky if you can get it lower.

air conditioners are designed to cool the cubic footage of the cabin, and no more. That means when it's really really hot out, you are going to struggle to get it "cold". That's been an issue with every tractor since the beginning of air conditioned cabins. John Deere a/c cabs are horrible, at least all the ones I've been in are.

Someone mentioned moving the a/c from the top to under the seat. I personally think it's easier to deal with under the seat rather than having to get up on a ladder & work over the top. Makes it a little less expensive to manufacture too (less hoses, cables, wires, etc). Makes a lot less mess when the time comes to have to clean the evaporator out too. Just remove it, it's on flexible hoses, pull it to the side and rinse. If it's in the top, you have to be really careful about getting water/cleaner/etc on the headliner and inside the cab. I have to line the entire top of the tractor with plastic and even then use lots of caution. Takes longer=costs more$$$.

Out here if you try to get the cab down much below 80 this time of year, you will have severe condensation developing on the windows. Right now the dewpoint is 76. At night it gets up around 78 or so. For instance this morning I was fishing on the river, and the water temperature was 64 degrees, and the fog was so thick along the water and up to about 30-35 foot above the water, that I could not see the front of my little 15' boat. Thats what happens to tractor windows too when the a/c is turned down below the dewpoint. Windows fog up and then you can't see no more.

Tinting the windows DOES help. Kubota doesn't do it because of liability. No tractor manufacturer does it to my knowledge (for liability reasons). You don't have to spend $1300. You can get it done cheaper. Also, worth mentioning, optional is to remove the top of the cab (the big orange plastic piece) and flip it over, then line it with some frost-king duct insulation. That seems to help big time. Combined with tinted windows, I bet one could get the cabin temp way down.
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
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Someone mentioned moving the a/c from the top to under the seat. I personally think it's easier to deal with under the seat rather than having to get up on a ladder & work over the top. Makes it a little less expensive to manufacture too (less hoses, cables, wires, etc). Makes a lot less mess when the time comes to have to clean the evaporator out too. Just remove it, it's on flexible hoses, pull it to the side and rinse. If it's in the top, you have to be really careful about getting water/cleaner/etc on the headliner and inside the cab. I have to line the entire top of the tractor with plastic and even then use lots of caution. Takes longer=costs more$$$.
Tell me about it. Been there and did that but what I did was first make sure the condensate drains were open and working properly and then (after propping up the blower housing because I wasn't about to pull the heater core), I took my garden sprayer and 'hosed down the HX with purple ZEP and then rinsed it with clear water, again with my pump sprayer. Did that 3 rimes until the water coming out of the condensate lines was running clear, so no headliner issues but I was careful. You don't want to be using a hose up there or you'll overwhelm the drains and soak the headliner
I'm not buying a new tractor just to have the ac under the seat pan. Not in the cards.

With my pusher fan in front of the underhood HX, even at an idle, my vent temps are 30 degrees below ambient and mine cools down (vent temp) pretty quick. I'd say within 5 minutes.

Said before, now that Dennis came out and topped off the refrigerant, if I have the blower control on anything other than one, it's too cold in the cab. Makes my arms ache.

I'd say (never checked, no need to) that my in cab temps are around 30 degrees colder than outside. It actually works better than I can ever remember it working but new was a while ago as it's a 2004.

Do I really want to pull the roof and do that again? Not really. The roof isn't a big deal to remove. It's very light. I can stand on my PTO shield and remove it myself, no big deal. Working on the overhead unit is a PITA as you have to use a ladder (or stand on a rear tire) or both, so I keep it on recirculate all the time now. No point in dealing with negative air pressure and the inherently leaky roof gasket (I did add another layer of closed cell foam when I replaced the gasket (that was almost 100 bucks) and I replaced the filter element gasket with a bulb gasket, The OEM filter gasket is worthless.

Lined the inside of my roof with foil-bubble-foil Reflectix (which is available at any box store). The roof, being orange and plastic soaks up the sun's heat. Every little bit helps.

I don't have any tint on my windows other than factory. Plenty enough for me.

I was running hay and it was in the 90's and I was cool as a cucumber inside the tractor and a big plus is the electric fan because when the motor is idling, underhood airflow isn't much and not much equates to poor heat transfer which equates to poor ac function.
 

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
Those are all nice suggestions but doesn't it seem odd to you that you would have to tint windows, add insulation to the top of the cab, add an electric fan to a brand new tractor to get the air to half way work. Two of my neighbors do hay with new holland tractors and they both stay cold with the air on low. I understand the 20 deg difference but if it is on recirc then it should just be working with the air in the cab and not outside air so as the air runs, the cab should get cooler as well as the air coming out of the vents. As far as the tint goes I got 3 quotes and they were all about the same, also they make an almost clear ceramic film that blocks 90% of the infrared heat so kubota shouldn't have to worry about liability with something like that.
 

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
Those are all nice suggestions but doesn't it seem odd to you that you would have to tint windows, add insulation to the top of the cab, add an electric fan to a brand new tractor to get the air to half way work. Two of my neighbors do hay with new holland tractors and they both stay cold with the air on low. I understand the 20 deg difference but if it is on recirc then it should just be working with the air in the cab and not outside air so as the air runs, the cab should get cooler as well as the air coming out of the vents. As far as the tint goes I got 3 quotes and they were all about the same, also they make an almost clear ceramic film that blocks 90% of the infrared heat so kubota shouldn't have to worry about liability with something like that.
Getting the pressure up to 2900 helped the loader but no change on the steering.
Rex
 

Rexr

Member

Equipment
M4D-071
Feb 7, 2020
39
1
6
Georgia
Rexr,
Did the dealer even bother to check the steering circuit’s pressure? If so, what was it.
They did I think he said the minimum specs was 1700 and I think the high was around 2600, I'm not exactly sure on the numbers but mine was in between the high and low so they did not do anything else with the steering since it was within specs. They are checking with kubota to see if there is anything else they can try. I will post it if they come up with anything.
 
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