John Deere Air Conditioning

[Anonymous-0]

The air conditioner on my John Deere is not getting cold, i think that it is my expansion valve but i am not sure. How do i tell if that is the problem, or are there any other suggestions for the problem.

 

[Bob]

A clogged expansion valve will cause extremely LOW (even a vacuum) low-side pressure reading.

A TXV stuck open will cause a unusually HIGH low-side pressure reading.

And... why not give us just a teeny, tiny clue as to what machine you are working on!

 

[Anonymous-0]

You may have a leak in the lines in the cab. My 30 and 40 series tractors lines failed when they were about the same age- each about 13 years old.

 

[Anonymous-0]

I am working on a John Deere 4430 Tractor, sorry I forgot to add that in the original question. All of the lines have been checked and there is no apparent leak. Everything that has to do with the air conditioner has been checked but the expansion valve.

 

[Anonymous-0]

Yep my guess would be same as yours. Happened to 3 of my 30 series tractors at about the same age.

 

[buickanddeere]

Checked for leaks with...........? Adding dye is the surest method.
A machine of this age pretty much needs every little piece brand new.

 

[Anonymous-0]

Check the receiver/dryer sight glass for bubbles if there are you are just low on freon, if you havn't had it checked in awhile. Receiver/dryer is located rear left hand side inside the cab brackets by the three-point arm. Brent

 

[Anonymous-0]

changed the cab air filter lately or removed the cab top and blown out the A/C?

 

[Bob]

If it has been converted to 134A, it is NORMAL for the sight glass NOT to clear up. If he ads refrigerant 'til it clears up, it will be WAY overcharged.

As a matter of fact, the last couple of dryers I've got from DEERE have the sightglass OMITTTED!

 

[Anonymous-0]

Connect a set of guages and you will know whether to look into the expanson valve. If it still has r-12 good luck on finding it and if you do be prepared to pay the price--best to convert to r-134 and know how much freon it takes--like what was said above if you put enough 134 in system to clear the sight glass it WILL be overcharged and it still will not work.

 

[Anonymous-0]

Gauges and pressure checks will tell the tale - the expansion valve could be stuck open or closed and affect the pressures accordingly. Another distinct possibility is that the compressor isn't engaging - is the thermal fuse good if there is one? Is the thermostatic switch sending current to the compressor clutch? Dyed refrigerant will pinpoint leaks in the future. Best way to make sure it's leak-free now is to pressurize the system with 250 psi of dry nitrogen and let it sit overnight. If it holds pressure, it's leak free. If you have to go after the expansion valve, be very careful, because the fittings tend to corrode over time and it's easy to damage the evaporator. The small sensing line is the worst, and Deere makes a weld-on replacement fitting that a competent aluminum welder can install if the threads come off the old one. As Bob said, there will still be bubbles in a properly charged R-134a system, so if it has been converted, make a note of that. You might also want to check the operation of the heater control valve - if there is hot coolant circulating through the heater core at all times, the A/C will never work properly. And if you open the system, be sure to replace the receiver-drier and evacuate the system with a vacuum pump for at least an hour or so before recharging, and making sure it holds a good vacuum is another good leak check. If the system is still R-12, refrigerant capacity is around 4.5 pounds. If it has been converted, you want about 80% of that, or around 3.5 lbs. Charge with a good scale - don't guess.

 

[Anonymous-0]

The pressures read between 30 on the low side and about 250 on the high side. The drier does not have a glass in it and it has been replaced, the compressor is engaging because the pressures are stabilized. The system has been flushed including the compressor and the expansion valve has been replaced, a vacuum was pulled on it for one hour and then charged with 3.5 pounds of 134A. The system has 12 ounces of pag oil. It is still not blowing cold air out of the vents. The air is cool but not cold. Since all of this was done are there anyother suggestions as to why the air might not be cold coming out of the vents.

 

[Anonymous-0]

The pressures read between 30 on the low side and about 250 on the high side. The drier does not have a glass in it and it has been replaced, the compressor is engaging because the pressures are stabilized. The system has been flushed including the compressor and the expansion valve has been replaced, a vacuum was pulled on it for one hour and then charged with 3.5 pounds of 134A. The system has 12 ounces of pag oil. It is still not blowing cold air out of the vents. The air is cool but not cold. Since all of this was done are there anyother suggestions as to why the air might not be cold coming out of the vents.