Tech tip: How to use a timer to pull a proper vacuum

Having an A/C RRR machine with an adjustable evacuation timer is critical to pulling the proper vacuum in all conditions.


Moisture in a vehicle's A/C system is the cause of most problems and complaints today. A/C repairs expose a vehicle's system to air and moisture, which can be picked up by the refrigerant and transported through the system with ice crystals forming at the point of expansion. If left in the system, this can greatly increase the corrosion of metals and damage a vehicle.

A vacuum pump is vital to remove moisture and air from the vehicle's A/C system. Most A/C RRR machines come equipped with a vacuum pump that can be used to evacuate the A/C system, while Robinair A/C RRR machines come equipped with an adjustable vacuum pump timer. The timer automatically defaults to 10 minutes. However, if service is performed in a high humidity environment, the timer can be set to 30 minutes or more, to ensure all of the moisture is removed. Using a timer allows technicians to service a vehicle's A/C system while also performing other tasks.

Information provided by: Robinair, Service Solutions LLC

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