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.