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AEM Update: Snap application for off-highway R-1234yf

September 22, 2021

MACS will have a variety of heavy-duty and off-road presenters beginning at 8 am on Thursday, September 30.  One will be AEM Update: Snap application for Off-highway R-1234yf
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Behavioral characteristics of various compressor types

September 21, 2021

When faced with a challenging A/C system problem, knowing what type of compressor you are dealing with can help streamline the diagnosis process. 
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Cooling fan circuit analytics

September 16, 2021

What is Peter Orlando’s class Cooling Fan Circuit Analytics about? It all began decades ago as a mechanical fan attached to the water pump with and without a fan clutch.  And now it has evolved into an efficient complex electrical motor control of cooling the modern internal combustion engine.
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A burned clutch is a symptom of another problem

September 14, 2021

Not much thought is given to compressor clutches until they fail, but they are extremely durable.  I have personally owned three vehicles that had between 200, 000 and 240,000 miles on them.  They all still had the original compressors and clutches, and they were still functioning perfectly.
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Facts to know about the compressor clutch coil

September 7, 2021

Checking the clutch air gap before installing a compressor is an important step in compressor installation. This is because of the possibility of a clutch air gap getting knocked out of adjustment due to rough handling or it being gapped incorrectly at the factory.  These issues of course can cause problems with clutch operation.  If detected and corrected before compressor installation, a lot of time can be saved.
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Finding right side up

August 3, 2021

Most condensers have different fittings on the inlet and outlet.  The locations of the inlet and outlet on most condensers will not allow lines to be connected incorrectly, even if the fittings do happen to be the same size.  Lastly, the designs of the mounts on most condensers prevent a unit from being installed upside down.  However, none of these characteristics apply to the condenser the technician had installed. 
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Did you install the condenser upside down and backwards?

July 27, 2021

The vehicle was a 1998 Chevrolet C 1500 truck with a 5.7 engine. The issue was excessive high side pressure. Almost as soon as the compressor clutch engaged, the high side pressure was over 400 PSI, and the high-pressure cut-off was turning the compressor on and off.
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Top three tips on orifice tube behavior

July 20, 2021

In the last four MACS blog articles we covered a lot of detailed information about orifice tube system behavior. We examined a system with a full refrigerant charge verses a 25% undercharge. Now it is time to condense it all down into three important takeaways.
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Low refrigerant charge and the search for real data part 4

July 13, 2021

When we examined the pressure readings and vent temperature readings last week, there was nothing showing up that indicated any charge issues (even operating with the 25% undercharge).
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What’s the word on R-134a price & supply?

June 24, 2021

The email questions are already coming in, and they go kind of how you’d expect: What’s going on with the price of R-134a? Is there going to be a shortage of R-134a supply?
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Low refrigerant charge and the search for real data

June 22, 2021

I had read about how low refrigerant charges could increase compressor operating temperatures and decrease the amount of oil flowing to compressors, but I had never been able to find results from any tests. After discussing this with MACS, we decided to do some testing to get some real data.
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Refrigerant capacity and mobile A/C service: part 2

June 15, 2021

One of the most frequently asked questions on tech help-line calls concerns refrigerant capacity: How much refrigerant is in that mobile A/C system, and have you checked to be sure the refrigerant is pure?
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