# AC Still Troubling



## Vol (Jul 5, 2009)

Well, I don't know where to start but I have just about done everything known to mankind with my AC on my JD 55 series tractor. New compressor, new dryer, new condenser out front, lines cleaned, heater hose shut off valve, and several other little things that I am too tired to recall tonight.

Tractor cools, but not quite where it should be.....about 50 degrees at the vents on a hot day.....should be in the lower forties ideally....and that makes a big difference on a hot day.....just not quite cooling like it once cooled....at one time, I would have to turn the thermostat down even on a hot day.

This all brings me to the latest.....I noticed last week that when I had the thermostat turned down to the lowest setting and then turned it up to its maximum cool setting that there was no difference in how it cooled(ususally I always had the thermo maxed so I never really noted this). So, I bought a new rotary dial thermostat from JD and installed it and it does the same thing.....no difference between low and high cool settings.....I feel like this is some kind of indication but I can't quite put my finger on it.

Regards, Mike


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## mlappin (Jun 25, 2009)

Only thing that comes to mind is did you clean the evaporator while everything was disconnected? I hate em when they are installed over head, the White four wheel drives had em at the bottom of the cab, could open the access door and clean em while still installed in the tractor.

I use a foaming spray to clean condensers and evaporator fins, its hard to believe how much stuff comes out of them that a garden hose doesn't touch.


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## cornshucker (Aug 22, 2011)

Did you replace the expansion valve.


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## mlappin (Jun 25, 2009)

cornshucker said:


> Did you replace the expansion valve.


I just assumed it was one of the little things he was too tired to recall, but a very real possibility.


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## Vol (Jul 5, 2009)

cornshucker said:


> Did you replace the expansion valve.


Yes.

Regards, Mike


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## Vol (Jul 5, 2009)

mlappin said:


> Only thing that comes to mind is did you clean the evaporator while everything was disconnected? I hate em when they are installed over head, the White four wheel drives had em at the bottom of the cab, could open the access door and clean em while still installed in the tractor.
> 
> I use a foaming spray to clean condensers and evaporator fins, its hard to believe how much stuff comes out of them that a garden hose doesn't touch.


Yes. They sell coil foaming cleaner in a aerosol can at Home Depot.

Regards, Mike


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## Hayman1 (Jul 6, 2013)

Mike-you just hit the nail on the head as to why I don't have my 2755 anymore. Loved that tractor, may be the best haying tractor ever made but I had a cab so I could have predictable artic air for 90 degree days and it just could not do that. Yes it cooled but not enough. Had multiple jd mechanics tweak it but to no avail. Would have sailed into the sunset with that tractor if the issue could have been fixed. Actually, I would have considered putting a modern one in it but I am not sure that even works. Good luck.


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## Tx Jim (Jun 30, 2014)

Have you considered installing manual heater hose shut off valves?? The heater water control valve on my JD 4255 would let some hot water pass through affecting AC cold air output until I installed and shut off water to heater core.


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## Vol (Jul 5, 2009)

Tx Jim said:


> Have you considered installing manual heater hose shut off valves?? The heater water control valve on my JD 4255 would let some hot water pass through affecting AC cold air output until I installed and shut off water to heater core.


See paragraph 1 in post 1.  I thought for sure that would be the culprit, but no dice.....

Regards, Mike


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## Tx Jim (Jun 30, 2014)

Vol said:


> See paragraph 1 in post 1.  I thought for sure that would be the culprit, but no dice.....
> 
> Regards, Mike


Heater hose shut off valve could indicate "factory water control valve" but I meant manual shut off valve installed in hose similar to photo..


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## Mike120 (May 4, 2009)

When you rebuilt, did you switch from R12 to R134???


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## Vol (Jul 5, 2009)

Mike120 said:


> When you rebuilt, did you switch from R12 to R134???


Yes.

Regards, Mike


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## mlappin (Jun 25, 2009)

Was this tractor bought new? If not I'm wondering if a previous owner managed to pinch the line somewhere going to the evaporator/expansion valve.

Have one of ours to fix, previous owner(s) never changed the receiver/dryer, has correct pressures but the line directly after the receiver/dryer gets cold on it's way back. It kinda works okay but fails miserably on a hot and humid day.


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## Vol (Jul 5, 2009)

Tx Jim said:


> Heater hose shut off valve could indicate "factory water control valve" but I meant manual shut off valve installed in hose similar to photo..


I know what you meant and yes I did install a shutoff in the heater hose line coming from the block. 
Regards, Mike


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## Vol (Jul 5, 2009)

mlappin said:


> Was this tractor bought new? If not I'm wondering if a previous owner managed to pinch the line somewhere going to the evaporator/expansion valve.
> 
> Have one of ours to fix, previous owner(s) never changed the receiver/dryer, has correct pressures but the line directly after the receiver/dryer gets cold on it's way back. It kinda works okay but fails miserably on a hot and humid day.


Yes I bought it new in 1990 but the AC on the 55 series are problematic on several models and it has been worked on many times from the late nineties on...I have not noted any line damage but neither have I inspected closely. I will do that. Thanks.

Regards, Mike


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## Vol (Jul 5, 2009)

Hayman1 said:


> Mike-you just hit the nail on the head as to why I don't have my 2755 anymore. Loved that tractor, may be the best haying tractor ever made but I had a cab so I could have predictable artic air for 90 degree days and it just could not do that. Yes it cooled but not enough. Had multiple jd mechanics tweak it but to no avail. Would have sailed into the sunset with that tractor if the issue could have been fixed. Actually, I would have considered putting a modern one in it but I am not sure that even works. Good luck.


I have never owned a tractor that handles like it does with the hydrostatic steering. It is my tedding and raking tractor and I run a little 7 foot disc mower on the hills. It is a very special handling machine....if it was not it would have been history 15 years ago.

Regards, Mike.


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## 560Dennis (Jun 1, 2015)

Interesting topic , I going convert my 91 buick to r134 , I read you cannot over fill them , like my Buick takes 32 oz, R12 , R134 only needs 28 oz. ,


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## Tx Jim (Jun 30, 2014)

Vol

How long did you pull a vacuum on the system? How many oz's of coolant did you install?? Have you considered installing an electric fan in the front of the condenser/radiator?


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## Vol (Jul 5, 2009)

Tx Jim said:


> Vol
> 
> How long did you pull a vacuum on the system? How many oz's of coolant did you install?? Have you considered installing an electric fan in the front of the condenser/radiator?


Vacuum pulled over a hour....3.5 lbs of coolant.....it has a new condenser....the radiator was power washed with a water wand made for that specific job.

Regards, Mike

P.S. Have not considered a electric fan yet.....one, I am not sure there is even enough room....and two, the AC used to work fine without a electric fan. I am told that there are people in Iowa that can solve my problem but I cannot find out who they are....I would haul the tractor to them when I am going in that direction to get this fixed and fixed right.


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## deadmoose (Oct 30, 2011)

Vol said:


> I have never owned a tractor that handles like it does with the hydrostatic steering. It is my tedding and raking tractor and I run a little 7 foot disc mower on the hills. It is a very special handling machine....if it was not it would have been history 15 years ago.
> Regards, Mike.


Sounds like a nice machine. Sounds like the perfect used green one for mid mn. If it doesnt work out you can drop it off here on your way to CO to get your 7810....

Hope you can fix it though. Good luck.


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## Thorim (Jan 19, 2015)

Well there are a few John Deere plants in Iowa maybe one of them could come up with a solution other then buying a new tractor


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## mlappin (Jun 25, 2009)

If it used to work okay, then it should work again.

Wish we were closer. Sounds like quite the challenge.


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## born2ride (Sep 1, 2014)

I am not familar with that tractor ,but a/c psi reading ? Low and high side? How are you charging it?30 pound can? Or something else that may have put too much oil in system ?


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## Nitram (Apr 2, 2011)

deadmoose said:


> Sounds like a nice machine. Sounds like the perfect used green one for mid mn. If it doesnt work out you can drop it off here on your way to CO to get your 7810....
> 
> Hope you can fix it though. Good luck.


Now hold up a minute there Moose...now Kansas is directly in the path to the land of the green stuff. Besides Vol likes me better Lol . Vol I am willing to meet ya on I-70!!! (I don't stand a chance do I )


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## Vol (Jul 5, 2009)

born2ride said:


> I am not familar with that tractor ,but a/c psi reading ? Low and high side? How are you charging it?30 pound can? Or something else that may have put too much oil in system ?


Readings are good low and high.

Regards, Mike


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## Tx Jim (Jun 30, 2014)

3.5#s sounds like too much coolant especially if you're installing 134A. My 4255 only requires 36 oz's of 134A and it cools better than it ever did on R12. 134A requires only 80% of factory recommended R12. After filling can you observe any bubbles in site glass on reciever/dryer?


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## Vol (Jul 5, 2009)

Tx Jim said:


> 3.5#s sounds like too much coolant especially if you're installing 134A. My 4255 only requires 36 oz's of 134A and it cools better than it ever did on R12. 134A requires only 80% of factory recommended R12. After filling can you observe any bubbles in site glass on reciever/dryer?


I will investigate the coolant amount Jim....thanks.

Regards, Mike


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## Vol (Jul 5, 2009)

Tx Jim said:


> After filling can you observe any bubbles in site glass on reciever/dryer?


The new dryers do not have the old style sight glass as far as I know.....maybe you can still buy them, but the one that I bought did not.

Regards, Mike


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## Vol (Jul 5, 2009)

Guess I will take the side and back glasses out and just use it as a open station fellas.  nahhhh....50 vent temperature is not cool when above 95, but it beats the crap out of a open station environment.

Regards, Mike


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## Vol (Jul 5, 2009)

Tx Jim said:


> 3.5#s sounds like too much coolant especially if you're installing 134A. My 4255 only requires 36 oz's of 134A and it cools better than it ever did on R12. 134A requires only 80% of factory recommended R12. After filling can you observe any bubbles in site glass on reciever/dryer?


After looking thru the tech manual I found that the old r12 full charge was 4 pounds.....so if 80% is the correct formula for 134a I should have put 3.2 pounds in instead of 3.5.....or 51 ounces versus 56 ounces.

Are you certain that the correct formula for 134a is 80% of r12 ?

Regards, Mike


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## Mike120 (May 4, 2009)

I assume:

1. When you replaced the dryer, you got a new one with R134 compatible desiccant,

2. You liquid flushed the system and replaced the mineral oil with a/c ester oil

3. You replaced the condenser with a more efficient parallel flow condenser

4. You pumped it down for a couple of hours hours. Any air will get trapped in the system (usually in the condenser) and cause a major reduction in the capacity and performance of the a/c. Additionally, it will raise the head pressure and cause the compressor to have to work harder.

5. After the initial fill, you determined the optimum amount of refrigerant to match your system by monitoring the a/c outlet vent temperature and the high side pressure as you added or removed refrigerant. When the ambient air temps get above 80o the gauge readings can run a bit higher on the high side and lower on the low side when using R134. You do not want to exceed the system's high side recommendations. The safe high side pressures are determined with a "PT" (pressures and temperatures) chart. This chart has a column of "ambient" (outside) air temperatures on one side and a corresponding range of high side pressures on the other side. The higher the ambient temperature the higher the high side pressure. By noting the ambient temperature you can look up what the preferred high side pressure should be. You should be using less R134 than R12 so you do not want to rely on the drier's site glass to determine if the system is full. With R12 you could check to see if the site glass was "full", if it had bubbles it meant you had a low charge. With R134 you can not rely on the site glass, you've got to rely on the gauges.

I suspect your problem is a combination of #3, #4 & #5. The devil is usually in the details.


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## mlappin (Jun 25, 2009)

Mike120 said:


> I assume:
> 
> 4. You pumped it down for a couple of hours hours. Any air will get trapped in the system (usually in the condenser) and cause a major reduction in the capacity and performance of the a/c. Additionally, it will raise the head pressure and cause the compressor to have to work harder.


One of my old manuals from Oliver/White actually suggested a minimum of 4 hours and to use a propane torch to warm up the metal components of the system to help drive any moisture out.

Now I keep a cylinder of nitrogen gas around to pressurize the system to find leaks, another added bonus is the nitrogen binds with any water and makes evacuation easier. I just bought a new Robinair vacuum pump last year, it will take a system down to 30 inches of vacuum in no time, then I usually leave it on for a few hours.


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## Tx Jim (Jun 30, 2014)

Mike120

My point about asking if there was a sight glass was with 134A & one sees "no bubbles in sight glass" then it has too many oz's of coolant installed.


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## mlappin (Jun 25, 2009)

Unless R12 and 134A are that different my Oliver/White manuals call for one half pound more after there are no bubbles in the site glass, this was for R12, but i do the same for 134A and several of em will still cycle on and off on all but the very hottest days.

In my limited experience an overcharge of oil causes poor performance before an overcharge of freon will. I know the last one we bought needs the receiver dryer changed, bubbles in the site glass but the high limit pressure still cuts out the compressor.

Maybe try googling this problem and somebody else on a different forum has already figured out the gremlins in the 55 series A/C system.


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## Mike120 (May 4, 2009)

Tx Jim said:


> Mike120
> 
> My point about asking if there was a sight glass was with 134A & one sees "no bubbles in sight glass" then it has too many oz's of coolant installed.


Most new ones don't even have sight glasses anymore. You are better off with tinkering with the system and the fill.



mlappin said:


> Unless R12 and 134A are that different my Oliver/White manuals call for one half pound more after there are no bubbles in the site glass, this was for R12, but i do the same for 134A and several of em will still cycle on and off on all but the very hottest days.


Boiling point is different... R134 boils at a higher temperature and you need different oil. R134 doesn't play well with Mineral Oil.

I used Freeze12 when I replaced the compressor in my 7710 a couple of years ago and couldn't really tell the difference. It's a mix of R142b (HCFC) and R134a(HFC).


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## Nitram (Apr 2, 2011)

Vol said:


> Guess I will take the side and back glasses out and just use it as a open station fellas.  nahhhh....50 vent temperature is not cool when above 95, but it beats the crap out of a open station environment.
> 
> Regards, Mike


Dangit....Moose it looks like neither of us is going to enjoy this tractor.


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## mlappin (Jun 25, 2009)

Mike120 said:


> Most new ones don't even have sight glasses anymore. You are better off with tinkering with the system and the fill.
> 
> Boiling point is different... R134 boils at a higher temperature and you need different oil. R134 doesn't play well with Mineral Oil.
> 
> I used Freeze12 when I replaced the compressor in my 7710 a couple of years ago and couldn't really tell the difference. It's a mix of R142b (HCFC) and R134a(HFC).


Right, but I believe another post stated that if you didn't see a few bubbles with 134A then you over filled the system.

I've tried a few of those drop in kits before, you know the ones where all you have to do is inject this compatibility agent and refill. Worked for a bit then the compressor chucked it cookies. I always purge and flush a system if it had R12 in them before. Anytime I have a tractor apart for a clutch job or whatever if the A/C wasn't a 110% before it gets purged and flushed. I've spent way too much time in tractors that the A/C had crapped out in to do it now that I can actually service them myself.


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## Tx Jim (Jun 30, 2014)

Mike120 said:


> Most new ones don't even have sight glasses anymore. You are better off with tinkering with the system and the fill.


Since JD 55 series tractors ceased being produced in 1993 I think Vol's model will not qualify as a "new one". I stand by my statement that when 134A is utilized if "no bubbles are present in sight glass" that this indicates that " too much 134A" has been added to system resulting in poor cooling performance. I agree that although not always possible especially if repairing AC system in the field measuring coolant is better than guessing amount.


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## Farmineer95 (Aug 11, 2014)

Vent temp at 50 when it is 90 outside I'd say the system is fine especially if it is 134a in a 55 series. Might be asking for more than what it has for cooling capacity. R12 will be colder since its boiling temp is colder than 134a. Sounds like oxymoron but take a look at the differencce in refrigerants. Evaporator was set up for r12, the surface area can be smaller with r12. Good luck.


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## Tx Jim (Jun 30, 2014)

My 4255 AC cools as good or better on 134A as it ever did on R12 BUT JD Mannheim utility tractors AC never cooled as effectively as the rowcrop models


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## born2ride (Sep 1, 2014)

I still would like to know what is low side and high side psi. Pressure readings can give and aid to diagnosis, Also how much oil was put in if any?, back before the 134a retrofitting was popular we were using autofrost in r12 system which was 3-5 degrees colder due to being a blend , but leaked out faster if system was not sealed!


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## Vol (Jul 5, 2009)

Farmineer95 said:


> Vent temp at 50 when it is 90 outside I'd say the system is fine especially if it is 134a in a 55 series. Might be asking for more than what it has for cooling capacity. R12 will be colder since its boiling temp is colder than 134a. Sounds like oxymoron but take a look at the differencce in refrigerants. Evaporator was set up for r12, the surface area can be smaller with r12. Good luck.


When I get a chance and not up to tail in alligators I will pull some refrigerant out as it probably needs close to a pound removed. The AC temp does not vary from a low thermostat position to a high one so something is definitely amiss.

I also have another lead that a JD tech here in Tennessee told me about that I intend to look into....I just need to catch a slow period but it will be awhile.

Regards, Mike


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## Colby (Mar 5, 2012)

Been a long time since I remember AC working in our 2555, that's why it's gone. It was a hassle and never got it fixed. If it's blowing at 50 degrees that's pretty good. I think our 20 series deeres blow at 40-45 degrees. 
I'm the type that I want the problem fixed right but what about tinting windows if they aren't already? I know it doesn't solve the ac problem but should keep the cab cooler?


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## Vol (Jul 5, 2009)

Colby said:


> Been a long time since I remember AC working in our 2555, that's why it's gone. It was a hassle and never got it fixed. If it's blowing at 50 degrees that's pretty good. I think our 20 series deeres blow at 40-45 degrees.
> I'm the type that I want the problem fixed right but what about tinting windows if they aren't already? I know it doesn't solve the ac problem but should keep the cab cooler?


It did cool in the lower forties at one time....so maybe it can again....it does have factory window tinting, but I thought I might go with a heavier silver tint so that it will not be as difficult to see at night like the dark tint can make it.

Regards, Mike


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## somedevildawg (Jun 20, 2011)

Vol said:


> It did cool in the lower forties at one time....so maybe it can again....it does have factory window tinting, but I thought I might go with a heavier silver tint so that it will not be as difficult to see at night like the dark tint can make it.
> 
> Regards, Mike


I hear ya on dark tint at night.....can be dangerous at times, I'm speakn of vehicles, but I'm sure it applies to tractors just as well.....they need to make "transitions" window tint, but I'd settle for "transition" sunglasses on the cheap. Tired of losing mine cause they're too dark inside and I somehow seem to lose them whenever I take em off the noggin.....


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## deadmoose (Oct 30, 2011)

Nitram said:


> Dangit....Moose it looks like neither of us is going to enjoy this tractor.


I was all set to bleed green. Even had my green hairdye purchased. Looks like I have to return it.

Can definitely see why a tractor bought new almost 25 years ago shouldn't be leaving any time soon.


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## 3srcattleco (Apr 24, 2014)

Here in Kansas it was 98 today with a 105 heat index. (Humidity is super high right now). My 4440 was blowing 37 degree air. Are the systems that different from 40 series to 55?


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## Nitram (Apr 2, 2011)

My 4430 is seldom over fan speed 1 max cold. But for Vol's tractor I'd suffer a bit. Lol. As he said it used to pump the cold so there is a problem somewhere me think. Ah Kansas!!


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## Vol (Jul 5, 2009)

3srcattleco said:


> Here in Kansas it was 98 today with a 105 heat index. (Humidity is super high right now). My 4440 was blowing 37 degree air. Are the systems that different from 40 series to 55?


Like TX Jim mentioned, the 55 series row crop tractors did not seem plagued with AC problems that the 55 series utility tractors have......it was miserable here yesterday heat wise and humidity wise also, the kind of heat that kills people if they are in smokers health....but it was tolerable in the cab but I was in it just to rake and pull some loaded wagons out of the field.

Regards, Mike


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## stack em up (Mar 7, 2013)

Just a thought, have you ever thought of putting an electric fan on the condenser? The 8000 series Allis Chalmers were plagued with air cond problems once people converted to 134. We found that the cooling fan didn't have enough poop in the pants to pull enough air through the condenser. Started adding electric fans to them and problem solved for the most part. Other issue was the evaporator would plug with dirt if the seal on top of the cab wasn't tight enough.


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## Farmineer95 (Aug 11, 2014)

Speaking of fans, does yous viscous fan drive have a lock up kit installed? If not try that, check the model availability from Deere or just make a couple straps. Does the viscous drive ever lock up under load? Is the engine running a bit hotter than it used to?

Another thought: Is the foam filter (recirculating) above you head clean? Seems people like to have the A/C on and windows open enough that over time the filters get nasty.


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