The Air Conditioner in the cab of my 3450 cools when the tractor is started and will provide cool air for about 5 or 8 minutes....then warm air. I'm burning up!! If I stop the tractor and turn the engine off for 20 minutes or so, the AC will provide cool air when turned on, then after 5 or 8 minutes.....back to the hot air. Can anyone help me solve this problem?? Thanks for the reply
Help!! Air Conditioner not Cooling
- Thread starter Robert J. Davidson
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Bmyers
Well-known member
Lifetime Member
Equipment
Grand L3560 with LA805 loader, EA 55" Wicked Grapple, SBX72 BB, LP 1272 mower
The first question everyone will want to know is have you cleaned your filters/screens for the radiator/air conditioning system to make sure they are getting good air flow?
Without high and low side pressure readings while its running it will be impossible to tell you what is wrong with it. Sure you will get a lot of “could be’s” with the info you provided. I am very reluctant though to give out info on repairing A/C issues to those with no experience with it (not being rude, just trying to keep you safe and don’t know your experience).
You can make some observations to help you decide if it is time to get the ac serviced by a tech,
The AC compressor will have an electric clutch. Watch it when you first start the engine. It must engage for you to get cooling.
Observe it for a while and you will see it release and engage as the system cools down.
When you experience no cooling observe the clutch...... I expect it will not be engaging. A possible sign of low refrigerant but there are other causes.
Your system will have a sight glass.
Whitetiger has previously made these comments. His opinion is one to take seriously:
You probably will not see anything in the window with the AC clutch engaged. Typically, the only time you will see anything are bubbles if it is significantly low and you will see occasional bubbles and liquid for a second or three as the clutch engages or disengages. You may randomly see a little oil crossing the window, but very rarely unless you just stare at it for a long while. Just because you do not see anything does not mean its dry, just that its clear which is a good thing.
Do not start adding canned refrigerant yourself. It is not a "do it yourself," type of job.
Rather, once you have a properly operating system, if you learn to watch the AC's pulse and blood pressure, aka the cycling of the clutch and the passage of bubbles, you will be able to detect when your system is getting into trouble and before it quits completely.
The best repair job will have any leaks detected and repaired. The system completely evacuated and then refilled with a specific weight amount of refrigerant.
Dave
The AC compressor will have an electric clutch. Watch it when you first start the engine. It must engage for you to get cooling.
Observe it for a while and you will see it release and engage as the system cools down.
When you experience no cooling observe the clutch...... I expect it will not be engaging. A possible sign of low refrigerant but there are other causes.
Your system will have a sight glass.
Whitetiger has previously made these comments. His opinion is one to take seriously:
You probably will not see anything in the window with the AC clutch engaged. Typically, the only time you will see anything are bubbles if it is significantly low and you will see occasional bubbles and liquid for a second or three as the clutch engages or disengages. You may randomly see a little oil crossing the window, but very rarely unless you just stare at it for a long while. Just because you do not see anything does not mean its dry, just that its clear which is a good thing.
Do not start adding canned refrigerant yourself. It is not a "do it yourself," type of job.
Rather, once you have a properly operating system, if you learn to watch the AC's pulse and blood pressure, aka the cycling of the clutch and the passage of bubbles, you will be able to detect when your system is getting into trouble and before it quits completely.
The best repair job will have any leaks detected and repaired. The system completely evacuated and then refilled with a specific weight amount of refrigerant.
Dave
Dave is right about the system except the evacuation part. No need to pump it down unless it has a serious leak and has lost all 134a. I would strongly suggest one, making sure ALL the HX's are clean and that includes not just under the hood but inside the cab (under the seat on newer models or in the roof (on earlier models).
From your description it sounds like you are either low on 134a or you have compressor issues but either way, I'd have it professionally serviced by your dealer. Most times, that can be done at you home as a service call. The tech will have the proper tools and gauges as well as a portable evac system and graduate for installing the correct amount of 134a.
At no time should you attempt to charge it with any auto parts 'charge in a can' 134a refrigerant. They take very specific amounts of refrigerant and if any components need replaced, a specific amount of PAG 46 oil.
Overcharging a system and excessively high, high side pressure will destroy the compressor and possibly rupture a line or the evaporator or condenser. Call your dealer and schedule a farm call.
Mine was acting up and I had Dennis (my dealer's head tech) come out and handle it. Took about an hour and a couple cold waters and I was good to go. I did, before he cane out, cleaned not only the rad thoroughly but all the heat exchangers under the hood and under the roof too plus I renewed the cabin air filter.
A week ago I was baling hay at 95 degrees ambient and it was 65 inside on fan setting ONE. Mine will freeze me out over fan 1.
Money well spent. I think Dennis charged me $100 bucks for the service call, 1.5 hours time at the shop rate and supplies or about 200 bucks.
One thing to insure loingevity as far as keeping the hard to access under the seat / hood heat exchanger is, run the unit as much as possible on recirculate. That way the already cool air in the cab is just recolled, not bringing in hot outside air to cool down. Much easier on the system that way.
I read a lot of comments about Kubota having marginal ac systems. Mine isn't though I wish Kubota had larger vents like JD has. With a JD, you can put a can of your favorite beverage in the ac vent to cool it...
Like Dave stated, it is NOT A DO IT YOURSELF PROCEDURE
From your description it sounds like you are either low on 134a or you have compressor issues but either way, I'd have it professionally serviced by your dealer. Most times, that can be done at you home as a service call. The tech will have the proper tools and gauges as well as a portable evac system and graduate for installing the correct amount of 134a.
At no time should you attempt to charge it with any auto parts 'charge in a can' 134a refrigerant. They take very specific amounts of refrigerant and if any components need replaced, a specific amount of PAG 46 oil.
Overcharging a system and excessively high, high side pressure will destroy the compressor and possibly rupture a line or the evaporator or condenser. Call your dealer and schedule a farm call.
Mine was acting up and I had Dennis (my dealer's head tech) come out and handle it. Took about an hour and a couple cold waters and I was good to go. I did, before he cane out, cleaned not only the rad thoroughly but all the heat exchangers under the hood and under the roof too plus I renewed the cabin air filter.
A week ago I was baling hay at 95 degrees ambient and it was 65 inside on fan setting ONE. Mine will freeze me out over fan 1.
Money well spent. I think Dennis charged me $100 bucks for the service call, 1.5 hours time at the shop rate and supplies or about 200 bucks.
One thing to insure loingevity as far as keeping the hard to access under the seat / hood heat exchanger is, run the unit as much as possible on recirculate. That way the already cool air in the cab is just recolled, not bringing in hot outside air to cool down. Much easier on the system that way.
I read a lot of comments about Kubota having marginal ac systems. Mine isn't though I wish Kubota had larger vents like JD has. With a JD, you can put a can of your favorite beverage in the ac vent to cool it...
Like Dave stated, it is NOT A DO IT YOURSELF PROCEDURE
I do, run a 12 volt automotive type pusher fan in front of the under hood HX because when the motor is idling, the cooling fan don't move a lot of air so the heat exchange rate suffers.
I wired mine via a relay to the compressor clutch feed wires so when the system calls for cooling and the mag clutch is energized, the automotive pusher fan is pushing air through the under hood HX and my system cools as well at an idle as when the motor is spooled up. I idle mine quite a bit.
I wired mine via a relay to the compressor clutch feed wires so when the system calls for cooling and the mag clutch is energized, the automotive pusher fan is pushing air through the under hood HX and my system cools as well at an idle as when the motor is spooled up. I idle mine quite a bit.
whitetiger
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Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Pinch closed one of the heater hoses going to the cab and try running you AC. Sure sounds like your heater's water shut off valve is not stopping hot water from circulating through the heater core. The heater puts out more BTU's than the AC does so you are getting hot air out of the vents rather than heat removed from the cab. When you let the engine cool down for 20 minutes, the AC again works until the coolant gets hot enough to override the AC.
My guess is debris is blocking air flow through condenser/radiator. I agree about pinching heater hose as I put manual cut-off valve on my tractors heater hose because original coolant valve was letting fluid through..
Yes, Mr. Bmyers, I have taken screens under the hood out and washed them with water to remove the dust. I also change filters quite frequently -- perhaps too often. I don't think the flow of air is the issue. Thanks for responding.
Robert
There are a few great sources of technical information on this forum and only the unwise fail to take heed of Whitetiger's posts.
Dave
If air flow across cond,rad & evap are excellent & heater water valve is controlling water flow then next step is to attach gauges & check high/low refrigerant pressures
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