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Discussion Starter · #1 ·
For the first hour or 2 it works great. Can freeze you out. Then all of a sudden it quits cooling and wont come back on for the rest of the day. The compressor quit pumping. It will pump if you hook power to the comp. clutch and will build up to about 250-275 psi but wont blow very cold at that. I've tried recharging the system from empty with the 4.2 lbs that was recommended to me by Case mechanic. I've changed the heater valve which was leaking a bit anyhow and the lines running to the cab seem cool. Tried jumpering the high pressure switch to see if that would make any difference. The aircon did work for a few hours of discing one day like that. So I replaced the high pressure switch thinking that was it. Rads are immaculately clean. Out trying to harrow today, same thing after a couple hours Aircon quits again. Did have a Case mechanic out at the end of seeding and said he's seen a couple Steigers like this that he couldn't get working properly.

Just wondering if anyone else has had this experience and what solution if any worked.
 

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Lines running to the cab should be quite cold I would think, not just cool. Especially the line coming off of the drier (not sure where they mount it). Had a swather this fall that would do something similar, although it would start working at the end of the day when the air outside was cooler. Recharged it twice with. Each time it would run well for a couple of hours. The last time it happened I noticed that the pressure on the low pressure side was quite high, much higher than the 40 psi it normally is. The condensor was not icing up. Ended up replacing the entire drier unit and the high pressure valve and that fixed it, knock on wood. There're are only so many parts to an AC system. Eventually if you replace everything it should work again! :)
 

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Discussion Starter · #3 ·
I was looking for it today but Im not sure where the dryer is on these tractors. Probably in the not so convenient to get at, under the seat location. When the system quits the the lines are all hot. Even when I hotwire the compressor to run, the low pressure doesn't get ice cold like it should. Maybe cool enough to touch thats about it. The Case mechanic that I had out had a theory that the R134 would start to boil in the system and no longer provide cooling till it cooled down completely.
 

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Discussion Starter · #6 ·
You need to flush the lines out. Likely need a new dryer and maybe expansion valve. Dryer comes apart and sends desiccant through the system. Our AC guy has done a few of those style of tractors. We had a tj500 that it happened to. Seat needs to come out to access it.
Had that exact same thing happen in a new Macdon swather. But it quit completely when that happened.
 

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Discussion Starter · #7 ·
Before you start throwing parts at it try to speed up the Hyd cooling fan in front so it cools your condenser properly. There is a screw to adjust it if have to look for it on our machine but a case tech could maybe pinpoint it better and tell you have much you can or should adjust it.
The Case guy I had out was playing with manually engaging the fan to full speed which brought the pressure down immediately. Said he had done some research to see if there was any software updates for these units which would have the AC high pressure engage the fan like it sounds newer units do but couldn’t find anything. Didn’t seem aware of any way to speed it up though.
 

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Discussion Starter · #14 ·
Actually though thinking back last fall was getting pretty cool out and it was still hot in the cab so I think it was not working even in the cooler weather.
 

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On a system that modern and to be having these problems with a well cleaned condenser I think it should have a new dryer and be evacuated. If the dryer has accumulated too much moisture the system wastes too much energy freezing and thawing the water molecules trapped in the old freon and the system can overheat.
It likely works good in the winter….. 🤔
 

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Discussion Starter · #16 ·
On a system that modern and to be having these problems with a well cleaned condenser I think it should have a new dryer and be evacuated. If the dryer has accumulated too much moisture the system wastes too much energy freezing and thawing the water molecules trapped in the old freon and the system can overheat.
It likely works good in the winter….. 🤔
Had absolute no problem in winter. Probably true what you say though. The system has never been serviced since new other than me replacing the R134a this spring.
 

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Discussion Starter · #18 ·
No no codes. But I'm trying to figure out why the compressor quits kicking in when the system quits. I put the guages on today after it quit and it was sitting about 150-200 psi. with the compressor not engaging. So I jumpered the high pressure switch to see if that would engage the compressor but it didn't. So what else, besides low pressure switch which I don't think it is, can override the compressor engagement? Mind you when I engaged it by hotwiring it, it still wouldn't provide any cooling.
 

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No no codes. But I'm trying to figure out why the compressor quits kicking in when the system quits. I put the guages on today after it quit and it was sitting about 150-200 psi. with the compressor not engaging. So I jumpered the high pressure switch to see if that would engage the compressor but it didn't. So what else, besides low pressure switch which I don't think it is, can override the compressor engagement? Mind you when I engaged it by hotwiring it, it still wouldn't provide any cooling.
It is likely a variable stroke compressor and it’s fully de-stroking because the pressures are getting too high and it try’s to save itself. If it tried to stay at full stroke with very high pressure differentials it would likely slip the clutch to death or burn the belt off it.
 
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