Help With A/C Question

[jenkinsph]

Hope the tech finds the problem for you, might be a loose connection to the compressor clutch. Usually if a system will run for two hours without issue then it would tend to be something electrical that is intermittent. Pretty hard to go from operating correctly for two hours in the heat of the day and have the actual system and refrigerant cycle change.

 

[jenkinsph]

On many newer cars using r134a they have a charge volume by weight. On my older cars using R12 after vacuuming out you knew to add a small can and reading the pressure gauges. I probably used two cans on the car system. I see articles about the r134a repairs using gauges but nothing about purging with a vacuum pump then filling by weight. In any event pressure gauges are used to check the performance. Low charge means the evaporator coil could be freezing the longer the tractor AC is running. The more it freezes the less air flow over it to help cool the conditioned air. https://answers.yahoo.com/question/index?qid=20090817181951AA20te6

You know I am sure that most people don't have a vacuum pump or recovery unit with proper tanks. I have it along with a lot of other AC stuff but I am in the HVAC business. Most of the people who attempt to make their own repairs start by adding refrigerant such as the R134a which is about all they can buy over the counter. They are being mislead by the tv commercials imo. if a system needs a charge then I want to know where the original charge went to. Vacuum pumps are still used for all of the refrigerants in vehicles and housing.

 

[Loadstar]

You know I am sure that most people don't have a vacuum pump or recovery unit with proper tanks. I have it along with a lot of other AC stuff but I am in the HVAC business. Most of the people who attempt to make their own repairs start by adding refrigerant such as the R134a which is about all they can buy over the counter. They are being mislead by the tv commercials imo. if a system needs a charge then I want to know where the original charge went to. Vacuum pumps are still used for all of the refrigerants in vehicles and housing.

Got to agree with you on this.

 

[sunnyside360]

I had exact similar problem as your description couple years ago. Turned out to be a bad/intermittent electrical connection. Had a mobile HVAC guy come to the house and work on the tractor A/C. I was in the cab operating controls as per his instructions when all of a sudden when he jiggled a wire the compressor went wild turning on and off. It was a plug connector that needed pushed all the way in. IIRC, it was on one of the sensors.
Check all your electrical connections in the A/C system.

 

[trook]

I just heard from my JD technician. He stated the expansion valve in the roof was stuck open. According to him, means that the freon moves too fast and does not have time to remove the heat from the cab. Also, and maybe more importantly, it caused excessive head pressure which caused the compressor to keep shutting off. He stated that replacing the expansion valve should definitely fix the problem. I hope so because I was definitely hot inside the cab yesterday with outside temps near 100 degrees!

 

[sunnyside360]

Hope that fixes your problem. I can relate to exactly how you feel.

 

[jenkinsph]

trook
good to hear this is resolved and ends your AC problems. It would be great if you can follow up in a month so that we know that you are fixed up for sure.

 

[Tx Jim]

Ditto what jenkinsph stated.

 

[trook]

I drove the tractor for about 30 minutes. The air temperature was MUCH cooler....about 45 degrees at the vents, and it was 95 outside. I was extremely comfortable with the fan speed on 2! Hopefully, this solves my problem and will help others with similar issues with the new 50x5 cab tractors.

I will report back toward the end of the summer with longer term results.

 

[jagster936]

I didnt see a report back..lol. Expansion valve is a rare problem. Similar thing happened in my house the summertime was over charged and in winter compressor would trip out in heat pump mode. So the expansion valve in the house was clogged or damaged. Replaced it solved years of intermittent frustrations and problems with the heat pump