MACS 609 Certification Practice Exam

During HFC-134a refrigerant recovery, what should you do if gauge readings indicate pressure in an A/C system after a 5-minute pause?

1. Leave the system as is

2. Repeat the recovery process

3. Replace the refrigerant

4. Check for leaks

The correct answer is: Repeat the recovery process

The appropriate action in this scenario—if the gauge readings show pressure in an A/C system after a 5-minute pause during refrigerant recovery—is to repeat the recovery process. This pressure indication suggests that there may still be refrigerant present in the system. When recovering refrigerant, especially with substances like HFC-134a, it’s critical to ensure that the system is fully evacuated. Repeating the recovery process allows you to attempt to remove more of the refrigerant, ensuring that the system is left in a safe state. Proper evacuation is essential not just for compliance with regulations, but also to prepare the system for any necessary repairs or for recharging with the appropriate refrigerant. In situations where there is still pressure detected, simply leaving the system as is could lead to potential issues later, such as incorrect functions or further leaks. Choosing to replace the refrigerant preemptively lacks justification, as the current levels and functionality of the system still need to be addressed. Checking for leaks could be a subsequent step if pressure continues to exist after recovery attempts, but it doesn't directly address the immediate issue of residual refrigerant. Therefore, repeating the recovery process is the most effective and safest choice in this scenario.