Too much freon???

[Complete Turf Care]

I have a 2011 Kubota L5740 that I have owned for several years. I bought it with about 250 hours and it now has about 1300 hours.

My air conditioner belt recently started to squeal when the compressor kicked on. Belts were tight and fairly new.

Googled it and thought it may be the compressor clutch going bad. Brought it to a mechanic and he agreed, so we ordered a new clutch from the local Kubota dealer. (About $700 with shipping)

Later today they called and said it's not the clutch, it was too much freon in the system. The took a little out and now it works fine.

My question is.....how can I get too much freon in the system? I know very little about AC systems, but I've never heard of that. It's great if that was the problem, because I have about 20 or 30 hours of work coming up for this tractor and it sure is hot right now. And I like saving the $700 for the clutch.

I know that no one has worked on the AC since I've owned the tractor.

 

[jaxs]

I'm glad to hear they didn't install the clutch which saved you $700 but I'm not buying any part of it. The fact mechanic would equate a slipping belt to the clutch tell's me he doesn't know the first thing about air conditioning and should not be working on them,,,,,,period. Too much Freon? Maybe,but that doesn't cause the belt to slip. That it no longer slip's after removing some Freon might be true but there has to be another problem if that's true. I would be more inclined to think when belt was changed earlier it was the wrong belt and wore enough to begin slipping. Let us know if it cool's as well as before.

 

[TractorGuy]

I would be curious if they evacuated the system and weighed in the correct charge? The ONLY way to determine it had an overcharge would be to weight the recovery cylinder before and after evacuating the system.

 

[4570Man]

How did you decide slipping belt equaled bad clutch in the first place? The fact that it was applying enough resistance to slip the belt obviously meant the clutch was good.

 

[jaxs]

The fact that it was applying enough resistance to slip the belt obviously meant the clutch was good.

Exactly!

 

[Coyote machine]

The OP didn't say anyone had changed the belt. In fact, he said no one has touched the AC, except the guy who let out some Freon. He did say the belt started squealing recently.

 

[searcyfarms]

im with you guys, I wouldn't want that guy working on my tractor and the AC, I just had my 5088 AC system serviced and the guy took out just over 2 lbs - replaced some orings and a seal in the compressor and put back in around 4 lbs or something like that. his has some kind of metering system on it and it does it in .1 decimals on his machine - so like if you want it to put in 2.1 2.2, 2.3 etc....that is what it puts into the system

it also reads that as it evacuates the system and it has pressure gauges that show what its doing also - I know I overcharged my truck and it didn't slip the belt it shut the compressor off - they will shut off the compressor in a low or high pressure condition for the Freon amount I don't think it causes the compressor to lock up but I guess it could if the pressure sensor was defective and not kicking it out

 

[Tractor Seabee]

Back in my AC&R Technician days we had two types of service techs; diagnostic technicians who could analyze a system, and parts changers who kept changing parts till they happened on the fix. Those guys often overlooked the second problem and it still wasn't right. It was fun following those guys and fixing their screw ups. Poor customer was stuck with a double bill and the first was usually higher. I would give them a diagnostic review so they could try to recover their first bill.

Auto type ACs have very little, if any, storage for excess refrigerant (Freon is a brand name of DuPont) so it is easy to overcharge if you do not have the data on quantity required and the precision metering device to add only that. It may quit soon if the real problem was a leak and air got into the system. Air or other gases in the system are non-condensebil at system pressures, take up refrigerant space, and raise head pressure. Excess head pressure will stall the compressor and squeal the belts. This is only one possible problem. There are others. You do not learn AC service by reading a book or stumbling around.

Ron

 

[jaxs]

The OP didn't say anyone had changed the belt. In fact, he said no one has touched the AC, except the guy who let out some Freon. He did say the belt started squealing recently.

I have a 2011 Kubota L5740 that I have owned for several years. I bought it with about 250 hours and it now has about 1300 hours.

My air conditioner belt recently started to squeal when the compressor kicked on. Belts were tight and fairly new.

Googled it and thought it may be the compressor clutch going bad. Brought it to a mechanic and he agreed, so we ordered a new clutch from the local Kubota dealer. (About $700 with shipping)

Later today they called and said it's not the clutch, it was too much freon in the system. The took a little out and now it works fine.

My question is.....how can I get too much freon in the system? I know very little about AC systems, but I've never heard of that. It's great if that was the problem, because I have about 20 or 30 hours of work coming up for this tractor and it sure is hot right now. And I like saving the $700 for the clutch.

I know that no one has worked on the AC since I've owned the tractor.

He did say belts are fairly new so that mean's belts had been changed.

 

[Complete Turf Care]

How did you decide slipping belt equaled bad clutch in the first place? The fact that it was applying enough resistance to slip the belt obviously meant the clutch was good.

I googled something like "ac belt squeals when compressor starts" and most of what I found was that belts were loose or worn. I didn't think that was my situation. I found a few discussions that said it could be the clutch.

The OP didn't say anyone had changed the belt. In fact, he said no one has touched the AC, except the guy who let out some Freon. He did say the belt started squealing recently.

Yes, the belts were changed about 300 hours back when I had some work done on the exhaust.

This mechanic is about 70 years old and knows his way around tractors. I doubt he has had any formal AC training, but he has been around. He said he checked the pressure and it was too high, so he let a little 'refridgerant' out and it seemed to solve the problem.

I guess I will find out when I get on a job with it........

 

[Dadnatron]

Too much pressure in the AC system (ie too much 'freon') will typically cause the compressor to NOT kick on. If you have a clutch problem, it could be that there was a discrepancy between what the clutch and belts were 'trying' to do and what the compressor would allow them to do were 2 different things.

I have a JD, and last year, my AC started decreasing its coldness. I tested pressure and it was low, so I just 'dumped' a can in the system, suspecting I had a leak, so I went to the high side of 'full'. After that, I still couldn't get any cold air... so I fussed around with it for quite a while, suspecting my AC was 'out' somehow that I couldn't recognize. I went online and one thing I found was that too much pressure/too full of a system will cause the compressor to not function. I checked pressures again, and they were still on the 'high' side, so I bled off some and bamm.... I watched my compressor begin cycling. I KNOW this can happen now, so I am extra careful to insure that I watch both the compressor and the gauge when I charge any AC system.

 

[Coyote machine]

He did say belts are fairly new so that mean's belts had been changed.

If you say so: it was not clear anything had been done, especially since he had said no one had touched the tractor since he owned it. Ambiguous much?!:confused2:
I go by what's written, unless of course what's said isn't what's meant, as in this thread.:confused3:

 

[Complete Turf Care]

So you did what we did and it helped your situation.

That痴 good to know.

 

[Coyote machine]

OP, here's what I'd like to know. If no one touched your tractor, except you, how did your AC system get over full to begin with? Systems do not overfill themselves. :confused2:

 

[The Fred]

I over charged my own 2 years ago when I installed a turbocharger on my L3940 Cab but the A/C worked just fine until this year when we have had unusually hot weather. It's the same A/C system you have.

My symptoms were a click up in behind the headliner (ceiling) and the A/C would blow warm until the click of the relay was heard again. There's a sensor in the high side line to protect the system in the event of over-pressurization. In my case the high side was bouncing off 300 lbs.

I recycled the charge and soon realized I had 1/2 pound too much R134a in there. Once I got the charge right the system is running perfectly.

I do fair amount of A/C work on cars and I see this issue come up after someone charges a system with a can from the auto parts store. In my case it was 8 ounces too much that reared it's head on the first 95 degree day we had a month ago.

The only way to get the charge correct is by weighing it. The other method is using a chart to check static pressure of the system in a temperature controlled environment. In your case at 70 degrees F your pressure should be 70 psi. It's hard to check outdoors but the best time is in the shop maybe first thing in the morning before you use the machine, Low and high side should be the same pressure.


Good luck, Fred

Pressure - Temperature Chart for HFC-134a

 

[4570Man]

OP, here's what I'd like to know. If no one touched your tractor, except you, how did your AC system get over full to begin with? Systems do not overfill themselves. :confused2:

I’m guessing it wasn’t.

 

[Complete Turf Care]

OP, here's what I'd like to know. If no one touched your tractor, except you, how did your AC system get over full to begin with? Systems do not overfill themselves. :confused2:

That's what I don't understand either.

I bought it with about 250 hours on it and I put another 1000 on it and I don't have any record of any maintenance to the AC, other than the belt about 300 hours back.

 

[Coyote machine]

Are sight glasses still used for auto AC systems? How about on tractor AC? Back when I had my shop we had a Snap-On AC station that included a vacuum system, a charge tank for old style Freon, and gauges to read pressures in the lines, etc., and an in-line sight glass where one could see flow of Freon through the glass. One could see if there were too many bubbles in the flow - and indicator of not enough Freon charge in the lines.

 

[countrybumpkin]

Very few if any have the sight glasses anymore.

1300 hrs and now it’s has to much Freon , I don’t think so, you have a something else wrong in the system someplace causing the pressure to build.

 

[The Fred]

Very few if any have the sight glasses anymore.

1300 hrs and now it’s has to much Freon , I don’t think so, you have a something else wrong in the system someplace causing the pressure to build.

HOT WEATHER this year compared to before.

What's going to make more pressure in the system if nobody fooled with it? That's right nothing will, think about it.