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SCRS presentation lays out how 1234yf is more time consuming to recover, recharge

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Education | Repair Operations
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The differences between Freon R-134A (R-134a) and R-1234yf air conditioning refrigerants were laid out during the most recent Society of Collision Repair Specialists (SCRS) meeting.

Barry Dorn, of Dorn’s Body and Paint, presented a comparison of the steps required to recharge and recover each refrigerant to raise awareness that the process takes significantly longer when using 1234yf.

“It takes over an hour longer to perform the same operation with [1234yf],” Dorn told Repairer Driven News following his presentation.  “This is an ongoing problem that needs to be highlighted and solved.”

He added that the tooling, equipment, seals, refrigerant, and workflow are completely different with 1234yf compared to R-134a, saying the newer option “has so many more safeguards to prevent leakage and contamination, those safeguard and processes take a lot more time.”

Right now, the two refrigerants are commonplace in the marketplace. However, under an Environmental Protection Agency mandate, R-134a is being phased out and R-1234yf became a requirement in 2021 for all new cars.

Dorn said that although some refrigerant manufacturers have said it takes less time to service the R-1234yf system, the belief is misguided because the timeframes and processes that were established decades ago are now outdated.

“Two or three pages of stuff is different about it,” he told SCRS board members last month in Indianapolis, Indiana. “There’s nothing that we all do that is the same that it was decades ago.”

Dorn credited Ben Crumpton, a certified diagnostic and recalibration technician at Dorn’s Auto Service & Calibration, with identifying the steps necessary to work on both systems to bring the issue to light.

Dorn shared the research with the industry, including the five steps necessary for R-134a refrigerant recovery, beginning with powering on the machine and then locating and connecting the high and low side hoses. 

From there, a technician should initiate recovery on a machine via a keypad, and then spend eight to 10 minutes recovering the refrigerant and draining the used oil. Finally, they should disconnect the high side and low side hoses.

Conversely, he said eight steps are required for R-1234yf recovery, beginning with powering on the machine and waiting for self-checks to complete, which takes about five minutes. 

The technician should then select “recover” through the keypad, locate and connect the low side hose and wait for the machine to analyze and identify the refrigerant, which takes another five minutes.

The technician should then locate and connect the high side hose. Then, they should wait for the machine to finish recovery and drain the oil, which typically takes between 15 and 20 minutes, Dorn said.

They should then disconnect the hoses before cleaning and resetting the machine to prepare it for the next operation.

For recharging R-134a systems, six steps are required beginning with powering on the machine and locating the high side and low side hoses. From there, initiating vacuum time via the keypad takes about 10 minutes, and then the technician should enter the required amount of refrigerant and oil.

They must then wait three to four minutes for the machine to finish charging before completing the final step: disconnecting the hoses.

For a R-1234yf recharge, meanwhile, Dorn said 20 steps are required, starting with powering on the machine and waiting for self-checks to complete. 

From there, the technician should enter the vacuum time which takes at least 15 minutes and a leak test time which takes at least five minutes via the keypad.

Then, they should connect the high side and low side hoses and press start. After 15 minutes of vacuum time, the machine pauses for five minutes to ensure the air conditioning system is holding the vacuum, he said.

For the next steps, the technician should fill the oil injector with the proper type and quantity of oil, then disconnect the low side hose and inject oil into the low side charge fitting before reconnecting the low side hose.

And then, if the previous vehicle used PAG oil and the current vehicle requires POE oil, the machine must do a hose flush that takes about 20 minutes.

Once that’s complete, the technician should enter the appropriate amount of refrigerant to be charged via keypad, prompting the machine to charge the system with 50 grams of refrigerant for a partial charge.

The machine then monitors the pressure for five minutes to ensure there are no leaks, Dorn said, adding the technician is simultaneously directed to check the system for leaks with an electronic detector.

After five minutes pass, the machine recovers the 50 grams and remeasures it to ensure there are no refrigerant leaks. Dorn said the machine must then pull the vacuum for five additional minutes ahead of the final charge, which happens with the quantity of refrigerant previously entered.

After that’s finished, he said the technician is prompted to remove the high side hose and then start the vehicle and turn on the air conditioning to the maximum setting to check its performance. Doing so will suck the remaining refrigerant out of the low side hose.

Final requirements involve removing the low side hose and the machine recovering any remaining refrigerant from the hoses and pull vacuum for three minutes. The machine can then be powered off and put away after it’s cleaned and reset for the next operation.

Danny Gredinberg, DEG administrator, said time isn’t the only consideration with R-1234yf. Compared to R-134a, the refrigerant is more expensive, as is the cost of necessary equipment.

He said many DEG inquiries have been submitted regarding the topic, including comments indicating labor time estimates do not include the cost of refrigerant and oil, or the test for leaks.

One DEG inquirer noted that the maintenance cost of the air conditioning machine is not included in the estimated labor time.

The recovery time aspect does not include overall recycling machine processing time or the evacuation, recharge, and testing of an air conditioning system following repairs, Gredinberg noted.


Featured image: Courtesy of Barry Dorn

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