Refrigerant Recovery & Recycling Flashcards

After recovering refrigerant and completing repairs, what must be done before recharging the system?

Answer: Pull a deep vacuum to remove air and moisture

The system must be evacuated to a deep vacuum (typically 500 microns or less) to remove air and moisture before recharging.

How long should a vacuum be held on an MVAC system during evacuation?

Answer: At least 30 minutes

A minimum 30-minute evacuation is recommended to ensure moisture is adequately removed from the system before recharging.

What does a 'decay test' after evacuation check for?

Answer: Whether the system holds vacuum, indicating it is leak-free before recharging

A decay test involves closing the manifold valves after evacuation and watching for vacuum rise, which indicates a leak that must be repaired before charging.

When recharging an MVAC system by weight, what is the most accurate method?

Answer: Using a calibrated electronic scale to measure the exact specified charge weight

Charging by weight using a calibrated scale is the most accurate method, ensuring the exact manufacturer-specified charge is added.

Where can technicians find the correct refrigerant charge amount for a specific vehicle?

Answer: On the vehicle's A/C system specification label under the hood or in the service manual

Every vehicle has an A/C specification label (usually under the hood) listing the refrigerant type, charge amount, and oil type.

Refrigerant recycled on-site using SAE J2788 equipment may be recharged into:

Answer: Only the same vehicle from which it was recovered

On-site recycled refrigerant can only be returned to the same vehicle from which it was recovered; it cannot be transferred to other vehicles.