JD 4440 A/C not cold

[RCEF350]

the A/C in my 1980 JD 4440 is not very cold. Compressor is running and full charged. How do I determine cause?

 

[72supr]

On my 4440 the heat control wasn’t shutting off. Clamp a vice grip on the heater hose and see if that makes a difference.

 

[620 John]

Do you have an A/C gauge set to check the pressures??

 

[Roger in Iowa]

The condensor in front of radiator and evaporator in cab roof need to be clean. Also the cab filter. Then we can talk again.

 

[JD Dave]

Do what Roger says and then install gauges for further diagnosis. Then tell us what your readings are.

 

[John in MD]

I had same problem with a 4440, I replaced the thermal limiter fuse and things seem to work again.

 

[Roger in Iowa]

the A/C in my 1980 JD 4440 is not very cold. Compressor is running and full charged. How do I determine cause?

Fan and AC belts must be tight and not slipping. Belt sheaves may be worn out and causing belts to slip. Especially if high hours and used in very dusty conditions.

 

[Tx Jim]

Radiator, condenser & evaporator need to be very clean of foreign material. AC belt backs need to extend out past edges of belt pullies. Pressures need to be monitored by observing gauges when AC is operating.

I installed manual cutoff valve in heater hose on my 4255 in 1994 & have never opened it but I live in Texas.

 

[MARK ROBKE]

You need gauges to determine most problems with A/C. See if the clutch is engaged, see if you can feel temperature changes on the A/C lines. Make sure you have good air flow across the condenser, and the evaporator. Make sure the heater valve or blend door is not allowing the heater core to override the evaporator. Sometimes too much refrigerant can be added which does NOT make it cool better. To properly check the charge, you should weigh it in, into a properly evacuated system, BUT, if you know what pressures to look for, you can usually determine if the proper amount of refrigerant is installed. Also, I strongly recommend running the engine about 1500 rpm when doing your checks- after all, this is close to the RPM that the engine will running when you are using it. And check the belt for proper tightness. Pressures will be different at idle. Internal problems can be: blocked expansion valve, or orifice tube, stopped up receiver drier, or accumulator tank, clogged line(s), or bad compressor, or faulty clutch. let us know what you find. Mark.