If oil was removed from the A/C system during the recovery process, the oil must be replenished at this time.

1. Select the correct graduated bottle of replenishing polyakaline glycol (PAG) oil for the R-134a A/C system being serviced.
2. Adjust the O-ring seal around the PAG oil bottle to the required oil charge level.

For example, if the bottle oil level is at 4 oz and ½ oz of oil is required, adjust the O-ring seal to 3 ½ oz as the final level mark.

3. Install the bottle on the oil injection system on the back of the unit.

Important: 

•	Keep the oil bottles tightly capped at all times to keep out moisture and contamination.

•	Never open the oil injection valve while there is positive pressure in the A/C system. This will result in oil blow back through the bottle vent. A/C system vacuum is required for this operation.

•	Never let the oil level drop below the pick up tube while charging or replenishing. This will allow air into the A/C system.

4. Open the valve at the top of the plastic container and watch the level of oil being drawn into the system.
5. Close the valve when the required oil charge has been pulled into the system.

Add compressor oil to the Harrison R4 compressor (P72 chassis) as follows:

•	If less than 30 ml (1 fl oz.) is drained, add 60 ml (2 fl oz) to the new compressor.

•	If more than 30 ml (1 fl oz) is drained, add the same amount that was drained to the new compressor.

6. Add the amount of oil shown on the information plate to the Seltec TM-16HD compressor (P92 chassis).

The amount of oil that the rest of the A/C system requires depends on the components installed by the coach manufacturer and the size of the system. Refer to the coach manufacturer's service manual for specific quantities that the system will need during charging or in case of oil loss due to large leaks.