John Deere 3520 Air Cond does not work
whiteturbo
Join Date: May 2005 Posts: 77 Shelby NC |
2008-06-25 154822
I have a 3520 cab tractor and the AC does not work well. I have charged it with 134 a at the rate of 2.8 pounds and it just does not seem to do very well at 95 or 100 degrees. Anyone have a cab that works well and any idea what i should try to get it going? It has never worked like i think it should but this summer heat is hotter than normal and it just is not doing well. I have around 325 to 350 psi on the high side when charging at 90 degree temp outside. I am thinking maybe the expansion valve may be stopped up or maybe i should replace the dryer.The lines going to and from the dryer get very hot is that normal?
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John Deere 3520 Air Cond does not work
earthwrks
Join Date: Dec 2003 Posts: 3853 Home Office in Flat Rock, Michigan Pics |
2008-06-25 154824
Personally, I wouldn't expect a lot from any AC ---home---car--etc.--to function at nearly 100 degrees! And you have to consider if the cab windows are polarized to screen out solar radiation. And if the cab itself which is likely made of steel and probably not insulated well, any cooling gains are lost through convection. I worked in the deep south ("it's a dry heat", my butt) for awhile and know that a coil will freeze over if the humidity is high. Then it's useless.
My skid steer has an enclosed cab and heat. No AC though. But even in high-90's heat I can remain cool enough with the 6 air ducts blowing on me. Funny story: the rednecks got a little indignant when they saw me emerge from my machine thinking I had AC on a bobcat---the look was like "yankee--you gotta be joking--AC in a bobcat!!) ....
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John Deere 3520 Air Cond does not work
kthompson
Join Date: Oct 2005 Posts: 5275 South Carolina Pics |
2008-06-26 154829
If the line that is getting hot is a much smaller line than the others, yes it can get very hot. The gases used have changed so the 134 means nothing to me. Are you sure the 134 is proper for your system? Some of the older systems will not take some of the newer coolants used. Take a temp check of the air coming right out the vents. If that air is cool, it may be the cooling is being lost as EW is saying. If not, probably your cooling system. IF the tubing on each side of the dryer is about the same temp for same diameter would doubt your dryer is the issue. No idea on the expansion valve question. You have checked to be sure your coils are all clean? kt ....
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John Deere 3520 Air Cond does not work
whiteturbo
Join Date: May 2005 Posts: 77 Shelby NC |
2008-06-26 154831
Yes it uses 134a the tractor is only a little over two years old. Most changed around the mid 90's to something other than R12. Yes filters are clean. I am going to check the lines today as i have ha problems with the low side leaking at the charge port.
Thanks
Jack ....
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John Deere 3520 Air Cond does not work
hardwood
Join Date: Dec 2002 Posts: 3583 iowa |
2008-06-26 154832
I think it is a miracle that they work at all. The modern farm tractor and combine cabs have so much glass that the glass itsself it actually a part of ther structure. If you look at one there is no frame around the window or door glass anymore. From experience I know that if the AC quits you just have to quit till it is fixed, even tho some of the windows can be opened the cab is not designed to be used that way, plus all the dust that will acumulate in the cab in a hurry. I will have to agree with EW that in 100 degree heat if you are getting enough cooling to make it tolerable in the cab I wouldn't expect much more on a tractor with the horsepower of a compact. On a regular farm tractor or combine that has anywhere from 100 to 300 Hp a big enough compressor can be used to not tax the engine much, but on a compact with less than 35-40 hp a big compressor would rob a lot of available power. ....
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John Deere 3520 Air Cond does not work
Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada Pics |
2008-06-26 154837
FWIW our Kubotas all have A/C in the cabs, although you won't freeze, it will certainly keep you reasonably cool, definitely better than not having it.
A few things that do make a difference though. Both the rad and the A/C cooler in front have to be kept clean, dust and debris kills the cooling effect fast.
Also, if you have the option, definitely set the system to 'recirculate' and not 'fresh' air, closing the system to outside air means it's cooling air that's already colder than outside air. It also helps keep the humidity way down doing it this way.
Finally, check that the coils in the cab itself are clean and free of any debris, ours need to be vacuumed and blown clear several times a year to stay clean and working well.
Best of luck. ....
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John Deere 3520 Air Cond does not work
whiteturbo
Join Date: May 2005 Posts: 77 Shelby NC |
2008-06-26 154838
I keep my tractor clean under the hood and outside. I have also changed the cabin filter i will check it agin today with the gauges and hopefully i have a leak that i can find. You know how it is i am using it and don't have time to stop and work on it. Yes it does work much better than no AC when it is working. ....
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John Deere 3520 Air Cond does not work
whiteturbo
Join Date: May 2005 Posts: 77 Shelby NC |
2008-06-26 154855
Found the condenser dirty i have been washing it off but did not remove the screen in front of it. After cleaning it the head psi came down to around 200 at 78 degrees outside and the inside temp at vent was at 41 to 45 degrees. I think it will work much better now. I will give it a try tomorrow. Thanks for all the help.
Jack ....
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John Deere 3520 Air Cond does not work
alfadavis
Join Date: May 2010 Posts: 5 South Alabama |
2010-05-24 171045
When I removed the cab intake filter, the condenser on my JD3720 was covered in mud. Apparently, the condenser had turned the dirty air it was supposed to be filtering into mud. Any one know how to safely clean the condenser? ....
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John Deere 3520 Air Cond does not work
whiteturbo
Join Date: May 2005 Posts: 77 Shelby NC |
2010-05-24 171047
Never cleaned mine except with a water hose but they make a coil cleaner that you spray on and hose off. Most heating and air dist.would cary this. May want to check with Deere and see how thye feel about cleaning with a coil cleaner. ....
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John Deere 3520 Air Cond does not work
alfadavis
Join Date: May 2010 Posts: 5 South Alabama |
2010-05-24 171051
So when you cleaned it with the water hose, it didn't seep water into the cab? Not knowing what is behind the condenser, I was afraid it would wet the interior. ....
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John Deere 3520 Air Cond does not work
hardwood
Join Date: Dec 2002 Posts: 3583 iowa |
2010-05-24 171053
Perhaps the drain tubes are clogged that go from the coil in the cab. If they are clogged you will have a mess and sonner or later water will start dripping from the cab ceiling when the system is roof mounted. Some of the later higher HP Deeres have the system mounted behind the seat. If you don't see water dripping from those hoses anytime the AC is running then they are clogged with dirt, chaff, etc. ....
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John Deere 3520 Air Cond does not work
alfadavis
Join Date: May 2010 Posts: 5 South Alabama |
2010-05-24 171054
Based on how dirty the filter and coil is/was, I am pretty sure the hose is stopped up. The hoses are mounted around the outside of the back glass - so how do you clean them? ....
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John Deere 3520 Air Cond does not work
hardwood
Join Date: Dec 2002 Posts: 3583 iowa |
2010-05-24 171055
OK, cleaning drain hoses;
First of all don't wear your Sunday clothes, you're gonna be a mess when you're done.
Compressed air sometimes works by holding a nozzel in the bottom of the tube and sorta sealing it off with your hand till you see or hear it coming out the top, then flushing them with water to further clean them out.
I have had to remove the hoses to get them out where they were easier to work on by running a wire or sometning thru first. The nipples where the hoses connect to the drain pan will be clogged too so clean them too.
Keeping a clean well sealed filter is the best way to prevent this from happening. I've had older tractors where other seals beyond the filter were bad which lets in dirty air too, or cracks in the plastic housing surounding the coil so look it over good, duct tape is your best friend on some of the older leaking sysrtems.
Good luck. Frank. ....
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John Deere 3520 Air Cond does not work
whiteturbo
Join Date: May 2005 Posts: 77 Shelby NC |
2010-05-24 171057
No it has two drain holes if u look on each side of the rear window you will have a black rubber hose on each side that the water drains from the ac. So the water should run out about as fast as it comes in. I had the top off mine and the headliner out to install a radio and if if water gets in there it has a hard molded roof between the headliner and the top or tractor. ....
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John Deere 3520 Air Cond does not work
alfadavis
Join Date: May 2010 Posts: 5 South Alabama |
2010-05-24 171059
Thanks so much for all your help. Your advices has been the most to-the-point I've been able to locate on the net - including the JD sites! Thanks again. Have a great Day.
....
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John Deere 3520 Air Cond does not work
marvin90
Join Date: Jun 2011 Posts: 2 Victoria Kansas |
2011-06-12 178957
I put 2 7 inch fans in front of the condenser. Seems to have made a significant difference, however, I have not used it in 100 degree weather yet with the new fans installed. It's always been inadequate in hot weather and would just barely keep up with the outdoor temperature at 80 degrees. ....
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