Branson 6530C still having AC issues

[dclt736]

No we did not blow the lines, i wanted to, but the garage did not want to add any air, and moisture to the system. It is one thing i think we should have done. I have purchased some gauges and when i have time, i am going to check pressures with system off, running and once it goes into a cycling mode, use a 12 volt supply to keep the compressor running to make sure it is spiking and not an electrical cause problem, ie faulty temperature probe or pressure sensor. And if we pump the system down again, i will do a full inspection of every part of the system and blow out every item. However, i have second cut hay to start very soon and need the tractor running so i am putting further work on the AC until after the cropping work is done.

 

[5030]

No we did not blow the lines, i wanted to, but the garage did not want to add any air, and moisture to the system. It is one thing i think we should have done. I have purchased some gauges and when i have time, i am going to check pressures with system off, running and once it goes into a cycling mode, use a 12 volt supply to keep the compressor running to make sure it is spiking and not an electrical cause problem, ie faulty temperature probe or pressure sensor. And if we pump the system down again, i will do a full inspection of every part of the system and blow out every item. However, i have second cut hay to start very soon and need the tractor running so i am putting further work on the AC until after the cropping work is done.

At least it's getting on towards fall and a bit cooler during the day so you won't suffer too much. Harbor Freight has a nice set of refrigeration gages. I have them as well as their 2 stage vacuum compressor and their refrigerant sniffer too. This fall I need to take the lid off mine and clean the evaporator again. I've bailed a lot of dry hay and the chaff from the bailer always seems to migrate forward. Even with the AC on recirc, I get chaff in the evaporator.

 

[dclt736]

True the weather is starting to be more pleasant now. I am looking forward to getting the gauges i have on order so that i can do more investigation on my own without having to get the tractor to a shop. I am also going to talk with my Branson dealer to get new o-rings for when i do open the system, i will want to replace them all with new ones.

 

[5030]

Probably a good idea. I had a leaking one on my wife's van and the sniffer found it for me.

 

[LouNY]

I would definitely blow the lines out it sounds like something is plugging up the system.
Does it have a drier/filter on it?
When I have blown out AC lines I've rented a nitrogen bottle and regulator, at the time the small cylinder was around $20 for the gas and cylinder rental at the local welding supply house.
You may have to remove some componets to blow out your system, such as the expansion valve.
Then reassemble and do a gentle purge through your gauge line

 

[cbg8670]

Yes dry nitrogen is best for blowing out lines and coils. Be careful applying 12 volts straight to compressor. Pressures can spike really fast. Piping fittings and Stuff does have pressure limits..

 

[dclt736]

Yes great care needs to be done with my idea of direct power to the compressor. However once i have the gauges, and if the system does start up normal, then i will just monitor the pressures and see what they show. But if the system is just cycling for less then a second, i don't think the pressure reading can be truly relied on. I have welding gas, argon/CO2 mix, would that be ok, getting the pressurize nitrogen will be an problem. I also spoke with my Branson dealer and he also thinks that i need to clean the system to insure that it isn't plugging the expansion value. He stated that it takes very little debris to cause a problem. He also mention that you can purchase a chemical cleaner to flush the system to help remove excess oil, dirt, scale etc better then just using compressed air or gas, but did say it is not cheap. He also mentioned that I could take the expansion value apart, if you first measure the location of the set screw that set the opening size. As i have the old one, i am going to take it apart and see if i find any sort of debris in it tonight.

 

[cbg8670]

Yes the chemical stuff is called "rx-11" flush

 

[Cougsfan]

A couple of things I would point out that you may be past considering, but are worth knowing;

Don't pay a lot of attention or get hung up on the lb. of charge the Manufacture says that system is supposed to take. Pay attention to what the gauges say instead. Charge until the high and low pressures are close to what they are supposed to be with the system running. My system capacity was way off from what the manual says. I don't remember the exact numbers, but the manual said something like it should hold 2.75 lb. and in fact it took somewhat less than 2 lb. to make things operate at the right pressures. My repeated over-charging in order to meet the manual's capacity specs was one of the problems that I had in getting the system to work correctly. I have heard of that same issue in many automobile systems.

Also I am not a big fan of re-using refrigerant. Often a tech will put the refrigerant from your system back into a bottle before opening it up and then put the same stuff back in when done. That sounds environmentally friendly and all, but what happens if that refrigerant was contaminated (air &/or moisture)? You will be looking for mechanical fixes when that isn't the problem.

 

[LouNY]

One other possibility for your problems came to me the other day. I'm not familiar with the piping Branson used with your tractor.
But on mine there are a pair of quick connectors on the lines, these are self sealing connectors to allow splitting the tractor without loosing the AC charge. They are similar to hydraulic quick connects in that they seal as they are disconnected. I wonder if one of them may be partially loosened and trying to seal shut.

 

[hornett22]

Doesn't sound like a refrigerant leak issue. Sounds like moisture or too much refrigerant, or pag oil. I'd try less than two pounds.

I also agree with another poster, go by the gauges, not the amount.

 

[dclt736]

Good evening TractorByNet family
My gauges came today, and here is what i have found which may help finally sort this out.
Sorry it will be a long read.
Hooked up the gauges to the system, tractor running but AC not turned on.
Pressures where equal at about 84 on both low and high. Outside temp was about 82 degees F.
Tractor was at idle, and this is important.
Turned system on, low side dropped down to about 45 and high increased to 175.
System was blowing cold air in the cab.
After about 3 minutes the high side pressure started climbing and reached over 400.
Low side was still holding steady as 45.
At this point the system started to cycle.
Note, that i had not done any work or cleaning at this time.
I shut the tractor down and then removed the screens from the rads and blow everything out as best i could without dismantling the front rad supports.
You have limited easy access with the screens removed.
The condenser did have some seeds etc in it, but i do not feel it was blocked.
After i did that i started the tractor up and turned the AC back on.
Pressures again 45 low and about 200 high, however this time i increased the engine RMP to 1500.
Now the low side dropped down to 35 and the high side increased to just over 200, going between 200 and 220.
I left the tractor run like this for well over an hour.
I then idled the engine, and within few minutes the high side was climbing up, low side was around 28.
High side continued to climb and started to cycle with a few minutes once the pressure hit over 400.
I then shut down the tractor.
30 minutes later, but now without the gauges, i start the tractor up, had the engine at 1500 and turned the AC on.
The system was blowing cold air, after moving the tractor i left if at 1500 for 20 minutes and it ran normal.
I then idled it down and within a minute the AC compressor was cycling.
So now hindsight being what it is, I now see that i only notice the cycling when i had put the tractor into a idle setting to do something.
This means to me that the problem shows up when the air over the condenser is low and or the AC compressor is at a slower RPM.
And since the condenser is half decent clean, does this point us in a good direction for the cause.
It is my understanding that the pressure in the system will be close to the outside temp and balanced when off, and this shows that the gas level is kind of in the right place, but is that 100 percent correct?
Does a high charge of oil make this sort of think happen? As i installed a new compressor that came loaded with oil, and i have no idea how much that was or what might have been in the lines etc. I did not do anything so far that would have removed excess oil, other then to replace the air drier.
Any new ideas, does the point to over/under charge, or excess oil or something else, condenser is bad?
If we feel that the bit of dirt that i removed from the condenser is the issue, then this will be a major problem, as there is no way i could keep the condenser clean like this while doing baling, bush hogging etc without stopping every hour and blowing out the condenser of the little bit of dust etc it would have picked up. It is sad to say, but the design of oil cooler and condenser placement even with a metal screen in front does little to stop debris from getting to them, the space is fully open across the bottom and sides and there is no way to easily add screen to those areas.
Thanks for any suggestions.

 

[hornett22]

Sounds like too much oil.

 

[cbg8670]

Not running pressure just tells you that there is refrigerant not that it proper amount. Could be oil or someother trash in system. Usually when u change compressor u get most of oil out with compressor.
It may be too much refrigerant...

I'd recover a lb and try it there

 

[Remstar]

I'd replace the condenser. Operating a high side pressure @ 400 psi indicates a system internal obstruction and will cause compressor failure. it's also very important to remove all moisture from the system to prevent sludge formation. Internally, AC systems have to be impeccably clean. The article below provides more info.

A/C Condensers: Flush or Replace - MyMoto Nigeria

mymoto.com.ng

 

[dclt736]

Thank you on the advice. I am going to have to sit on this for a while as cash is running low, and the season is getting to the point that AC is not going to be as critical.

 

[LouNY]

I use my AC often in the winter to dehumidify the cab and get the frost of the inside of the windows.

 

[5030]

I use my AC often in the winter to dehumidify the cab and get the frost of the inside of the windows.

So do I. I run mixed ac / heat in the winter all the time actually.

 

[5030]

One nice thing my Kubota's have in the ac system is a sight glass inline with the dryer. It's very easy to see refrigerant flow and if there is a good or interrupted flow. Even the shop manual (WSM) refers to it. They call out that id there are 'bubbles' in the flow, the charge is insufficient whereas if the flow is absent of any bubbles, it's sufficient. The dryer is placed out front so it's easy to see the sight glass too.

 

[5030]

Additionally, unless you replace major components in any system, adding additional compressor oil is not a good thing as the PAG oil will already be there and today, most replacement compressors will already have an oil charge in them.