L4060 Cab model AC issue

[Gnlandrus]

I have a new to me L4060 with 760 hours. Love it but I’m have in a AC issue.
It’s not cooling like it is supposed to. I have started looking for the problem and discovered the compressor is cycling on and off very quickly. It runs for about a second and disengages after about a second, re engages a couple of seconds later and runs for 1 second again.
I have done some research and found the most common problem is low Freon. I put 1, 12oz can in and it’s still doing it.
Any ideas? Bad pressure switch?
Also, I don’t see anything in the sight glass when the ac is running.
Any/all help appreciated.
Greg

 

[S-G-R]

Any insight @BBFarmer ?

 

[BBFarmer]

I have a new to me L4060 with 760 hours. Love it but I’m have in a AC issue.
It’s not cooling like it is supposed to. I have started looking for the problem and discovered the compressor is cycling on and off very quickly. It runs for about a second and disengages after about a second, re engages a couple of seconds later and runs for 1 second again.
I have done some research and found the most common problem is low Freon. I put 1, 12oz can in and it’s still doing it.
Any ideas? Bad pressure switch?
Also, I don’t see anything in the sight glass when the ac is running.
Any/all help appreciated.
Greg

I reckon it could be any of the above.

Typically when an a/c system is "short cycling" the most common issue is the system is low on freon. A low pressure switch will detect this and disengage the clutch on the compressor.

I'm speaking totally "automotively" of course and ASSUMING a tractor a/c system would function similar to automotive. @North Idaho Wolfman or a few others could clear this up pretty quickly for us.

Of course numerous other issues will and can create this same symptom.

High side pressure increasing above a rated high pressure switch (increased engine temperature, decreased air flow through condenser/radiator (grass seed or half your field clogged up in your rad screen), restriction in expansion valve/orifice tube (not even sure what a kuboter system has, never even looked at mine) would create similar symptoms.

No, before any conclusions are jumped to, gauges would need to be hooked up, pressures evaluated, so you would definitively know whether or not to turn right or left down the lovely road of actuate diagnostics. This is how the parts cannon gets loaded, fired, and MISSED! Swaptronics comes into play and people start donating money LOL.

You would want to know.... is the low side pressure switch disengaging the a/c clutch due to the freon rapidly exiting the system.... is the high side pressure disengaging the clutch due to too high of head pressure, is an ambient temp sensor going open (typical default automotive is -44) also disengaging the clutch.... the symptom count could be high.

Put some gauges one her and see why the a/c clutch is disengaging and get back to us.

 

[North Idaho Wolfman]

@BBFarmer nailed it.
You need some gauges to figure out what is really going on with it.

 

[Tx Jim]

Adding refrigerant to an AC system without monitoring high & low pressures is the wrong thing to do. Too much R14A will cause AC system not to cool the same too small amount of refrigerant. Monitoring refrigerant pressures is the only correct method for correcting the AC problem.

Is AC condenser, evaporator & radiator very, very clean so they all have good air flow through the fins/tubes???????

 

[Old Machinist]

Ditto on the need to put gauges on it.

99% of the time short cycling is low charge. You can sometimes get by with charging by gauge readings and get away with it. You want to see around 30 on the low side and no more than 250 on the high at 1500+ RPMs. Before you add any more get a can with dye in it to help find leaks. If it's low it's leaking somewhere.

Before you start to do anything on a tractor AC you need to clean the screens, radiator, and condenser. You can back wash the radiator and condenser with a hose but do NOT use a pressure washer.

The only way to know if it has the correct charge is to pull a vacuum on it and charge it with the correct amount listed on the decal under the hood.

Then there is always the chance the evaporator is dirty. I've had the top off my LX3310 and there wasn't an easy way to get at and clean the evaporator so I just put it back on. Mine is cooling well but if it wasn't I would have to go deeper.

My tractor began locking up the compressor and when I put gauges on it the high side was pegged. It did have a dirty radiator and condenser from mowing some oats so that was contributing but having bought it used I had no way of knowing how much charge it had so I suspected it might have been over charged. I went ahead and evacuated the system and put it on a vacuum for a couple hours and charged the specified amount of R134A into it. It has been working good ever since.

It's also not a good idea to let one idle a long time in hot temperatures.