With your Manifold and Gauge set connected to the Vehicle and all taps closed, connect the Yellow Centre outlet hose to the Inlet side of the Recovery unit that also has its tap closed.
Open the outlet tap on the recovery unit and inlet tap on the recovery bottle, ensure mode tap is in the Recovery position and with the yellow centre line of the manifold and gauge set connected to the inlet port on the Recovery unit, turn the recovery unit on.
The safest way to recover from the A/C system is to open the Low side tap of the manifold set to the centre yellow line and slowly open the inlet tap on the recovery unit monitoring the initial refrigerant flow on the gauges to ensure that liquid is not introduced to the inlet of the recovery unit. This is highly unlikely from the low side which is why it is suggested. It is possible to recover from the high side of the system by opening the High side manifold Gauge to the recovery unit and again carefully opening the inlet tap to the area marked “Liquid” which is designed to minimise the likelihood of liquid entering the Recovery unit by restricting flow.
Once and liquid has been recovered this way and pressures are dropping the inlet tap can be fully opened. Liquid should always be suspected to be present especially if the A/C in the vehicle has been running. Once the Blue Gauge on the Recovery unit has pulled into a vacuum the Inlet and outlet taps can be closed and the Recovery unit turned off. You will need to allow the A/C system sit and monitor the manifold gauges for a short time to make sure there is no liquid still boiling off left in the system.
Purging the Recovery Unit
Purge the Recovery unit of any Refrigerant that it currently holds by turning the mode tap to Purge and the inlet tap to Purge. Connecting the outlet tap to a hose that in turn is connected to your recovery bottle, the outlet tap and bottle tap can now be opened and the machine switched on. This will purge the machine to the recovery bottle.
Once the Blue Gauge on the Recovery Unit show zero pressure or into vacuum the outlet tap can be closed, the mode tap turned back to Recovery and Inlet Tap Closed. The Recovery unit can be switched off. You can now drain the Oil Trap at the back of the Recovery Unit to see if you have recovered and therefore need to replace any oil in the Vehicle A/C system based on the measured amount out of this oil trap.