# Kubota Air Conditioner



## fpbone30253 (5 mo ago)

M6800 sn 0421 A/C works 30 minutes then stops cooling. I cutoff blue light (compressor) for 30 minutes and A/C runs another 30 minutes then start cycle over. Yes, radiator screens are kept clear. as well as hood screens. Dealer seems not interested in ,y issue. I think its the compressor clutch. Any suggestion?? frank


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## nota4re (Jul 3, 2021)

My first inclination would be to look at the expansion valve. I think your problem is likely either the expansion valve or possibly the clutch....


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## Fedup (Feb 25, 2014)

Expansion valves don't come and go. They either work or they don't. What are going to look AT? Just an aluminum block with fittings on both sides. If you want to look at something, look at the evaporator core. It's right next to the expansion valve, and depending on operating conditions and filter maintenance (or lack thereof) it could well be covered over with dirt, fluff, all the same stuff you find on the radiator. 

How well does the thermostat work? If you turn it down to a lower setting does the compressor clutch cycle off longer before it comes back on? Does it cycle at all or is it just on all the time? If it's on continuously it can cause ice in the evaporator fins, blocking airflow. No airflow no cooling in the cab. Shut it off, ice melts. Then it will work again for a while until it happens again. These are things you could be "looking at". To do much more than that you really need a set of gauges to monitor what the system is doing and when it's doing it. 

If you have little or no air conditioning experience, you may consider finding someone who does. Yes, it may cost you for a service call, but you might be far better off that way than you would be taking inaccurate advice. 

The 6800 is old enough it shouldn't have near the electronics of the late model Kubota cabs, so trouble shooting of the thermostat circuits, if it comes to that, should not be too complicated.


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## nota4re (Jul 3, 2021)

Fedup said:


> Expansion valves don't come and go. They either work or they don't. What are going to look AT? Just an aluminum block with fittings on both sides.


OP has an issue where the AC performance is inconsistent - sometimes it works, sometimes it doesn't. The expansion valve is just that - a valve and is susceptible to getting clogged or stuck. You could say the same dumb thing about any part, "they either work or they don't" . Given the symptoms described, yes, the compressor clutch could be giving out but I think it is a higher probability to be an expansion valve.


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## Fedup (Feb 25, 2014)

nota4re said:


> OP has an issue where the AC performance is inconsistent - sometimes it works, sometimes it doesn't. The expansion valve is just that - a valve and is susceptible to getting clogged or stuck. You could say the same dumb thing about any part, "they either work or they don't" . Given the symptoms described, yes, the compressor clutch could be giving out but I think it is a higher probability to be an expansion valve.


 Clogged or stuck, yes, but stop and start at thirty minute intervals? How many of those have you seen?


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## fpbone30253 (5 mo ago)

Thank you so much for the possible suspect problem areas. Will take copy of this discussion for dealer to contemplate ( I can't spell "mul-over") frank


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## dvcochran (Nov 23, 2010)

fpbone30253 said:


> M6800 sn 0421 A/C works 30 minutes then stops cooling. I cutoff blue light (compressor) for 30 minutes and A/C runs another 30 minutes then start cycle over. Yes, radiator screens are kept clear. as well as hood screens. Dealer seems not interested in ,y issue. I think its the compressor clutch. Any suggestion?? frank


You really need to determine what the pressures are when it stops working (and when it is working). It could be dropping out on high pressure, then coming back on after the pressures stabilize. High pressure can be caused by a number of reasons, blocked air flow on either the condenser or evaporator is the most common. It could be the TXV or solubles in the system. It could also be the compressor clutch or coil getting hot, then cooling back off. I have also seen the on/off button fail and cause this problem, but the light would also be intermittent.


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## drclean (9 mo ago)

fpbone30253 said:


> M6800 sn 0421 A/C works 30 minutes then stops cooling. I cutoff blue light (compressor) for 30 minutes and A/C runs another 30 minutes then start cycle over. Yes, radiator screens are kept clear. as well as hood screens. Dealer seems not interested in ,y issue. I think its the compressor clutch. Any suggestion?? frank


MY TRACTOR DID THE SAME THING,,,IT HAD CLOGED AIR FILTERS, AND CONDENSER IN FRONT, AFTER CLEANED IT WORKED AND YOU WILL GET TOO COLD SOMETIMES


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