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MACS Modern HVAC textbooks in stock for back to school

July 28, 2021

MACS Modern HVAC textbooks are in stock for back-to-school purchase.
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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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Come to Orlando for MACS 2021 Training Event

July 21, 2021

Pete Meier of Motor Age explains the value of attending MACS 2021 Training Event and Trade Show!
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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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Important deadlines for MACS 2021 Training Event

July 19, 2021

Time is running out to participate at MACS 2021 Training Event.
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Truck A/C is a hot commodity

July 14, 2021

Look out on your local highway, and what do you see? Truckers getting the job done. They want their cabs to be cool in summer and warm in winter. They want the climate system to work right. There is no time for downtime. That is where we come in.
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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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MACS Service Reports: a valuable member benefit

July 9, 2021

The MACS Service Report is a valuable MACS member benefit. Published nine times annually for dues-paying MACS members, MACS Service Report is an in-depth technical newsletter.
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We can’t wait to see you in person!

July 8, 2021

We are just a little over two months away from the rescheduled 2021 MACS Training Event and Trade Show! We can’t wait to see you in person September 30 through October 2 at the Rosen Centre Hotel in Orlando, FL. The golf tournament will be played on September 29 at the Rosen Shingle Creek Golf Course.
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Low refrigerant charge and the search for real data part 3

July 6, 2021

To place as much heat load on the system as possible, we turned the heat in the shop up on high and got it as hot as possible before beginning the test. When the temperature peaked at 89°, we began the test. We tried to keep it constant, but all the heat being generated by the engine in the test vehicle caused it to inch upward by 2.5° before the second test was concluded.
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A/C for E-trucks

July 1, 2021

Are you ready for E-trucks? Find out in the July/August 2021 issue of MACS ACTION magazine.
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Low refrigerant charge and the search for real data: part 2

June 29, 2021

The purpose of the test was to run an orifice tube system with a full refrigerant charge and then with a 25% undercharge and compare pressure readings and temperatures at strategic points in the system.
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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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Mobile A/C training when you want it!

June 14, 2021

If you’ve been too busy or the COVID-19 situation has made it difficult for you to attend mobile A/C training MACS has the solution.
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Time to make your Rosen Centre Hotel reservation for MACS Training Event

June 10, 2021

Time is running out to make your 2021 MACS Training Event and Trade Show hotel reservation at the Rosen Centre
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In this heat, check the back seat

June 9, 2021

in this heat, check the back seat
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Refrigerant capacity and mobile A/C service

June 8, 2021

One of the most frequently asked questions on tech help-line calls is: 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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Robinair sponsors free Section 609 test prep webinar and test for 500 technicians this summer

June 7, 2021

Robinair sponsors free Section 609 test prep webinar and test for 500 technicians this summer
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Electrification and climate control technologies: Are we prepared?

June 3, 2021

A recent survey from CarGurus suggests consumer interest in purchasing an electric vehicle (EV) has doubled in the past three years.
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Focus on the condenser!

May 31, 2021

In last week's article, we focused on applying temperature testing to an evaporator in an orifice tube system. In it we illustrated how and why a low liquid level in the evaporator can cause a large temperature differential between the inlet and outlet. We also indicated how and why raising the liquid level will cause the temperature differential to decrease. Now it is time to focus on the condenser.
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Show me your MACS 609 card

May 26, 2021

When you purchase refrigerant in quantities of two pounds or more you must show your Section 609 card.If you are Section 609 certified through MACS between 1991 and May 2021...
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Temperature testing detective work: The search for a diagnosis

May 25, 2021

Last week we closed our blog post with a discussion about an orifice tube system which had an evaporator outlet temperature that was about 20° warmer than the inlet. We mentioned that this could be an indication of a restricted orifice tube or a refrigerant undercharge. In applying this to diagnostics, it is important not only to understand what this represents, but also why.
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FutureTech Auto Presents Virtual Automotive Software & Electronics Fundamentals Boot Camp with Sponsorship by Mobile Air Climate Systems Association (MACS)

May 19, 2021

After launching the virtual edition of the ASE award-winning Automotive Software & Electronics Fundamentals Boot Camp in May, FutureTech has partnered with MACS to present an accelerated course track in Fall 2021.
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What is your temperature testing data telling you?

May 18, 2021

If air conditioning systems were transparent where we could see inside them, then diagnostics would be faster and easier. We could look at the systems and see things right away that affect system operation, like restrictions and liquid levels in evaporators and condensers.
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Do you have the essential tools for success?

May 17, 2021

Using the correct tools to service and repair vehicles is so important that the Society of Automotive Engineers (SAE) creates standards for some service tools to meet. Requirements for their use by service professionals is included, as well. Some examples include refrigerant recovery and recycling machines, refrigerant identifiers and leak detectors.
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AIM: EPA’s HFC Authority Is On!

May 14, 2021

On December 27, 2020, President Trump signed into law the Consolidated Appropriations Act, which at $2.3 trillion is one of the largest spending bills in US history. It combines $600 billion in COVID relief with $1.4 trillion in twelve different appropriations bills. One of them is the AIM Act.
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Temperature Matters

May 11, 2021

In addition to having good contact with connectors and getting accurate readings, there are some other important things to remember when doing temperature testing.
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Pass the temperature probe

May 4, 2021

The first step is to run the A/C system for a few minutes to let it stabilize. Then both probes should be connected side by side at both points that will be temperature tested in the system. For example, if you were testing the temperature drop across the condenser, this would need to be done on both the discharge line and the liquid line.
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Registration is now open for MACS 2021 Training Event and Trade Show

May 3, 2021

Come join MACS in Orlando, FL to attend the 2021 Training Event and Trade Show, registration is open
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Are you using the right tools for mobile A/C repair?

April 30, 2021

Your shop’s R-134a recovery/recycling/recharge (R/R/R) machine is in well-maintained condition. You have an R-1234yf gauge manifold set and an R-1234yf machine is on order; should arrive shortly.
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Contact counts in temperature testing

April 27, 2021

Proper contact is vital when connecting to A/C lines using the contact type temperature thermometers. To determine if I am getting good contact, I always like to place both connectors side by side on the same line and observe the temperature readings.
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MACS Mobile A/C Update Webinar Now Available On Demand

April 22, 2021

Every year the Mobile Air Climate Systems Association creates a special mobile A/C update clinic to help working technicians keep up with the rapidly changing mobile A/C service and repair...
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Today is Earth Day

April 22, 2021

Today is Earth Day!
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Tips for taking your mobile A/C system’s temperature

April 20, 2021

The contact type units do indeed have a high degree of accuracy, but precautions must be taken when using them (especially connecting to lines) to ensure the accuracy. Otherwise, it is possible to get readings that are easily 5° to 10° off and that can lead to an incorrect diagnosis.
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The pressure is on

April 19, 2021

By appearance, radiator caps seem to be a simple device. Yet, many technicians do not understand the cap’s real function
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Temperature testing accuracy

April 13, 2021

Temperature readings can be easily used to determine if an orifice tube system might be undercharged, and they can also be used to charge an orifice tube system. But if the readings are not accurate, all they are going to do is cause you problems.
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The Humble Mechanic, Charles Sanville to deliver MACS Keynote address

April 12, 2021

Charles Sanville, known as The Humble Mechanic, will deliver the Keynote address for MACS 2021 Training Event and Trade Show in Orlando, FL.
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Then things got complicated!

April 9, 2021

It was a 2013 Camaro. The complaint was poor cooling and the temp really would not change when you switched it from heat to cool. In diagnosing the job, the technician found the blend door was stuck to where it was blending heat. Until it was pulled out, the tech was not sure if it was a bad actuator or door.
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MACS upcoming training clinic, register today!

April 7, 2021

MACS will present Peter Orlando from CARQUEST Technical Institute for a Mobile A/C Service Essentials webinar. May 13
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Avoiding an oily situation

April 6, 2021

If you own a mobile A/C repair shop this is when you start to gear up for it, by replenishing your parts inventories and an important segment of those inventories is compressor oil.
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Preseason Training: A Service Manager’s Guide to Preparation

April 1, 2021

Proper training can limit the time period that any given mechanic spends in the novice stages of their career, and it may help them advance to expert performance levels in an expedited time period.
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How to deal with a compressor oil viscosity change

March 30, 2021

dealing with a catastrophic compressor failure where system flushing and component replacement removes all the oil from the system, then it is a matter of just installing the correct quantity of the oil that is specified for the replacement compressor.
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Texas Truck A/C thrives for 25 years

March 29, 2021

As Texas Truck A/C owners, employees, and customers celebrate the company’s 25th anniversary of being in operation, this business demonstrates what it means to not only survive for 25 years but to thrive.
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Help wanted!

March 26, 2021

MACS member repair shops are hiring
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ParkSmart Bunk A/C System Freightliner P3 Cascadia

March 24, 2021

The ParkSmart auxiliary HVAC system has been offered to replace the standard auxiliary HVAC unit.
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Why does the replacement compressor use different oil (than the original unit)

March 23, 2021

That is viscosity and specifically why a replacement compressor might use a different viscosity oil than its OEM counterpart.
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Does the compressor contain oil?

March 17, 2021

A question that comes up frequently on A/C tech lines is: Does the compressor contain oil and if so, how much?
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Marks Air celebrates 50 years of mobile air success

March 16, 2021

MACS member Marks Air Inc. celebrates 50 years of being in business.
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Tank full of air!

March 15, 2021

The problem is usually caused by excessive air in a system, and since too few shops use a refrigerant identifier, they don’t know when these problems come up, nor how often they are solving problems by doing this.
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What is MACS Membership?

March 12, 2021

How do I become a MACS member?
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Time to plug into EV training

March 10, 2021

Read any automotive publication or website, and you will see numerous stories from all the big automotive manufacturers and quite a few shiny new start-ups about vehicle electrification.
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How much oil “goes” in the compressor?

March 9, 2021

There is also an additional step which is required in the oil draining process with this unit. That step is that the suction damper needs to be depressed to allow proper ventilation when draining one of these compressors.
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Helpful tips to register for MACS online training clinics

March 5, 2021

Helpful tips on how to register for a class on the MACS website
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“Balancing” oil balancing

February 23, 2021

What should we do if performing an oil balance and only 1/4 oz of oil drains from the original compressor
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Caveman to Mr. Cool

February 18, 2021

Over 300,000 years ago, modern man began walking the earth relying heavily on his five senses-- especially sight – to hunt, find joy, and avoid danger. In 1914, Garrett Morgan, who decided it was important to protect man’s eyes during hazardous situations, developed what we know today as ‘safety’ glasses.
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Fix it correctly the first time

February 15, 2021

A cooling system classroom lesson By Christopher J. Holley, MACS Contributing Editor A 2017 Accord with an overheating 2.4L engine arrived at our college lab. The customer had a limited...
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A Change in Temperature

February 10, 2021

Using a contact thermometer, they quickly discovered 50° on the suction line at the expansion valve, and down at the compressor it read 96°. Along any length of hose or tube, there should be very little change in temperature.
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Compressor Oil: When is it enough?

February 9, 2021

But how do we know that a system has the correct amount in it to start with?
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MACS Board of Directors Elects 2021 Officers

February 8, 2021

The board of directors of the Mobile Air Climate Systems Association (MACS) met virtually Friday, February 5, 2021, and elected officers for the year. Andy Fiffick of Rad Air Complete...
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Stop by macsmobileairclimate.org for a visit

February 5, 2021

Visit MACS at macsmobileairclimate.org
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Doing the repair right

February 4, 2021

By Richard Hawkins, MACS Contributor The focus in the two previous weeks articles on the Chevy Tahoe was on what went wrong and what should have been done to correct...
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The beginning of a New year, new MACS!

February 1, 2021

The Mobile Air Conditioning Society has rebranded to become the Mobile Air Climate Systems Association (MACS). During a year-long project, the MACS board and staff worked with the Blue Door...
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Tales from the helpline: When they don’t know, what they don’t know!

January 26, 2021

By Richard Hawkins, MACS Technical Contributor Last week, my topic of discussion for the MACS blog was a tech call about an A/C system which was plagued by a huge...
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MACS announces new 2021 Training Event and Trade Show Dates

January 25, 2021

The MACS 2021 Training Event and Trade Show will take place Thursday, September 30 through Saturday, October 2, 2021 at the Rosen Centre Hotel and Convention Center in Orlando, Florida....
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How much compressor oil is too much?

January 19, 2021

By Richard Hawkins, MACS Technical Contributor A lot of interesting calls are encountered when working on an A/C tech help line and a large percentage of them involve lubrication issues...
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Let me tell you a story…

January 12, 2021

I conducted my first A/C clinic in 1991 which of course was 30 years ago. That was right along the time when things were getting geared up for the transition from R-12 to R-134a and was a very interesting period.
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MACS 2021 Board Election Results

January 6, 2021

The results of MACS board of directors election are in. The following members were elected for a two-year term, Andy Fiffick of Rad Air Complete Car Care of Cleveland, OH...
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MACS to reschedule the 2021 Training Event and Trade Show

December 17, 2020

Due to the circumstances of the pandemic and out of an abundance of caution for the safety of our attendees and staff, the MACS board of directors has decided to...
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OSHA and HazCom citations

December 14, 2020

By Charles Ayers, CCAR By the time you read this, the Occupation Safety and Health Administration (OSHA) will have released its “Top 10 Most Frequently Cited” list for fiscal year...
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HEVs and EVs still seeking best solution for HVAC

December 10, 2020

By Keith Leonard Another summer season has gone by while being unavailable for many activities usually enjoyed by almost all of us. The cover is back on my pool. While...
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Understanding data lines Part II

December 2, 2020

By Larry Turay Part I of understanding data lines was in the last issue, coverering data line structure and communications. Part II will cover troubleshooting and diagnoses of the J1587/1708...
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Safety Alert: Online Sales of Cool Penguin F-12

November 23, 2020

The United States Environmental Protection Agency (EPA) recently identified online sales of a product marketed as “Cool Penguin F-12” for use in motor vehicle air conditioners (MVACs). While the product...
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Disinfecting of vehicles during COVID-19

November 10, 2020

By Ward Atkinson, MACS Technical Advisor, & Bill Hill, GM Retired Recent comments from government agencies on the COVID-19 virus issue indicate that even when a vaccine is available, our...
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Modern cabin heating

November 2, 2020

By Frank Tonon, Qualification and training director, CPA Montreal Cabin heating through the yearsThe evolution of climate control in the past century has gone through several changes. From heated stones,...
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Hazmats: Why should I care?

September 21, 2020

by Charlie Ayers Trivia question: what do R-134a, Lithium Ion batteries, air bag modules, and used fuel system components all have in common? Aside from the fact that these are...
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Bringing in business in tough times

September 11, 2020

By Angie Chabot, AAM As the world battles a pandemic, businesses, like yours, are battling to keep customers coming in the doors. Just when it seems that every penny must...
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Back to basics

September 9, 2020

by Steve Schaeber There is no doubt that when it starts getting hot outside, your shop gets slammed with customers asking for help with their A/C systems. Same thing happens...
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Understanding data lines (Part I)

September 8, 2020

By Larry Turay Data lines and multiplexing have been with us in the heavy-duty world since 1990. The increased use of ABS, electronic ICUs, and automated transmissions to name a...
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Are you a diagnostic detective?

September 3, 2020

By Pam Oakes, SME automotive professional If you consider yourself a diagnostic detective see if you can solve this cooling system mystery before the end of the article! Cooling Corner:...
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Spend some time with MACS president and coo Elvis Hoffpauir

July 24, 2020

Hello, and Welcome to MACS Worldwide’s YouTube Channel. We’re glad you’re here! Elvis Hoffpauir Pioneer Experience MACS History! Elvis Hoffpauir, MACS president and chief operating officer, was presented with a...
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MACS Live Chat (Richard Hawkins and Steve Schaeber discuss Service Port Location)

July 7, 2020

This live chat features Richard Hawkins, A/C Tech line specialist and MACS technical contributor. Like many of you are during this Coronavirus Pandemic, all of us here on the MACS...
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Name That Hybrid Water Pump

June 29, 2020

By Dave Hobbs, MACS Technical Correspondent While virtually every HEV (hybrid electric vehicle) has an ICE (internal combustion engine) along with one or more high voltage electric motors, not every...
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Meet MACS Member Joey Rosato of Texas Truck A/C

June 17, 2020

Joey Rosato is second-generation and Director of Marketing for family-run Texas Truck A/C in Dallas, TX. Joey tells us, “It all started in 1996, when Nick Rosato (Joey’s Dad) set...
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MACS Live Chat (John Duerr & Steve Schaeber discuss A/C Leak Detection Tracer dye & COVID-19 in NYC)

May 28, 2020

Hi everyone, and welcome to another MACS Live Chat, hosted by Steve Schaeber, manager of service training and technical editor for MACS publications like ACtion Magazine and the MSR (MACS...
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MACS talks to GDP’s Julian Hentze about mobile A/C parts, repair and more!

May 7, 2020

A conversation with MACS member Julian Hentze of GDP
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Stop complaining about the technician shortage…

April 8, 2020

…and DO SOMETHING ABOUT IT! By Elvis Hoffpauir C.O.O. MACS Worldwide That was the principal message from Peter Meier, Director of Training at Motor Age. Peter, along with MACS Technical...
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Helpful tactics to minimize the spread of Covid-19 in your service and repair shop

April 7, 2020

By Bill Snow, Radair Complete Car Care, Cleveland, OH With today’s concern about being exposed to COVID-19 shop owners need to take additional steps to protect their team members and...
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