Vacuum Restrictor HVAC: Service and Repair

NOTE: Replace accumulator and restrictor whenever moisture or contamination (blockage) have entered refrigerant system.

- Discharge A/C system.
- Remove A/C compressor and plug all refrigerant line connections.
- Remove compressor oil drain plug, drain old refrigerant oil from compressor and measure amount.
- Rotate compressor by hand to speed up oil draining process.
- Dispose of used refrigerant oil following laws governing hazardous waste disposal.

CAUTION: To ensure lubrication during initial start-up, add at least 80 cc (2.7 oz) of fresh refrigerant (PAG) oil to A/C compressor.

- Refill compressor with 80 cc (2.7 oz) of fresh refrigerant oil.
- Install oil drain plug.

If total amount of refrigerant oil drained from old compressor was greater than 80 cc (2.7 oz):
- Subtract 80 cc (2.7 oz) (amount of new oil that was added to compressor) from total amount.
- Add resulting amount of fresh refrigerant oil to evaporator.

Example:
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100 cc (Amount of oil drained from old compressor)
-80 cc (Amount of fresh oil added to new compressor)
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20 cc (Amount of fresh oil to be added to evaporator or accumulator)

NOTE: Some refrigerant recovery/ recycling/ recharging equipment have provisions for adding refrigerant (PAG) oil during system recharge. If using this method for adding oil, follow all refrigerant/recovery/ recycling/ recharging equipment manufacturer's instructions.

- Replace restrictor. Expansion Block/Orifice Tube
- Install A/C compressor.
- Remove accumulator and plug all open line connections.
- Blow compressed air through component and collect oil that runs out.
- Add same amount of new refrigerant (PAG) oil to new accumulator plus 30 cc (1.0 fl oz).
- Install new accumulator.
- Evacuate and recharge A/C system.
- Manually rotate A/C compressor 10 rotations before operating system to prevent compressor damage.

NOTE:
- Install new accumulator immediately after opening to prevent moisture contamination of desiccant.
- Only use new O-rings specified for use with R-134a.
- O-ring and torque specifications also apply to threaded connections in the A/C lines.
- Make sure that A/C refrigerant lines are properly insulated from exhaust system heat.