AC Receiver/Drier

This procedure covers removal and replacement of the AC receiver/drier on a 2009 Aston Martin DB9, including refrigerant recovery, component replacement, and system recharge.

Warnings

Tools required

Parts

• AC receiver/drier assembly × 1 — Use OEM specification (Aston Martin part 6G33-19C836-AA or equivalent)
• AC line O-ring kit (various sizes) × 1 — Use OEM O-rings compatible with R-134a and PAG oil
• PAG 46 compressor oil × 1 — 50ml minimum for system replenishment

Fluids

• R-134a

Preparation

1. Verify AC system refrigerant charge level and document any existing performance issues
2. Ensure vehicle is on level ground with parking brake engaged
3. Allow engine and AC system to cool completely (minimum 2 hours after operation)
4. Place fender covers to protect paint during work
5. Connect refrigerant recovery machine and prepare manifold gauges
6. Prepare work area with adequate ventilation for refrigerant recovery
7. Have replacement receiver/drier, O-rings, and PAG oil ready to minimize system open time

Procedure

1. 1

   Recover refrigerant from AC system
   Connect refrigerant recovery machine to high and low side service ports. Follow recovery machine operating instructions to fully evacuate R-134a from the system. Continue recovery until system pressure reads 0 psi on both high and low sides for at least 5 minutes. Document the amount of refrigerant recovered for recharge reference. Disconnect recovery machine and cap service ports immediately. Note: Use OEM specification (verify correct Aston Martin receiver/drier part number against official parts catalog for 2009 DB9) Note: Use OEM specification; verify exact Aston Martin receiver/drier part number against official parts catalog for 2009 DB9 before ordering Note: Use OEM specification — verify correct Aston Martin receiver/drier part number against official parts catalog for 2009 DB9 before ordering Note: Use OEM specification; verify the exact Aston Martin receiver/drier part number against the official parts catalog for the 2009 DB9 before ordering.
2. 2

   Access receiver/drier location
   Open the hood and secure with prop rod. The receiver/drier is located near the condenser at the front of the engine bay; verify exact side and mounting (condenser-integrated or chassis rail) against the vehicle service manual before proceeding. Remove the engine cover(s) per service documentation, confirming the number and type of fasteners for this vehicle. If access is restricted by the air intake duct, loosen the clamps and reposition the intake tube for working clearance. Note: The receiver/drier is located near the condenser at the front of the vehicle; verify exact location against factory service documentation for the 2009 DB9. Remove any engine covers as required for access (fastener count and type to be confirmed from service manual). Note: Remove the engine cover as required for access; verify the exact fastener count and type against the service manual.
3. 3

   Disconnect electrical connector
   Locate the pressure switch or sensor on top of the receiver/drier. Press the locking tab and disconnect the electrical connector. Secure the connector away from the work area to prevent damage.
4. 4

   Disconnect AC line from receiver/drier inlet
   Locate the inlet line connection at the top of the receiver/drier (typically from the condenser). Determine the AC line connection type from factory documentation (spring-lock coupling, flare nut, or captive-bolt block fitting) and use the appropriate method to carefully disconnect the inlet line. Expect a small amount of residual refrigerant or oil to escape. Immediately cap the open line and receiver/drier port with clean plastic caps to prevent moisture and contamination entry. Inspect the O-ring on the disconnected line and note its size for replacement. Note: Verify the AC line fitting type for this vehicle (bolted block fitting, threaded coupling, or spring-lock) and use the appropriate disconnect method/tool to carefully disconnect the inlet line. Note: Disconnect the inlet line using the method appropriate to the fitting type on this vehicle (bolted block fitting, flare nut, or spring-lock coupling); verify the fitting type against the service manual before applying tools.
5. 5

   Disconnect AC line from receiver/drier outlet
   Locate the outlet line connection on the lower portion of the receiver/drier (typically routing to the evaporator or expansion valve). Using the same method as the inlet line, disconnect the outlet line fitting. Immediately cap both the line and receiver/drier port. Inspect and note the O-ring size for replacement.
6. 6

   Remove receiver/drier mounting hardware
   Locate the receiver/drier mounting bracket bolts or clamp fasteners securing the unit to the condenser or chassis. Confirm the exact number and type of mounting fasteners against service documentation before removal. Remove the mounting fasteners and carefully extract the receiver/drier from its mounting location. Note the orientation and routing of the unit for installation reference. Note: Confirm the mounting fastener count and type from factory service documentation before removal. Note: Verify the exact number and type of mounting fasteners against the service manual before removal.
   Torque spec

   Receiver Drier Bolts10 Nm (7 lb-ft)
7. 7

   Prepare new receiver/drier
   Remove the new receiver/drier from its sealed packaging only when ready to install. Remove the shipping caps from the inlet and outlet ports. Add 20-30ml of fresh PAG 46 compressor oil into the inlet port of the new receiver/drier to replenish oil removed with the old desiccant unit. Rotate the unit gently to distribute oil internally. Keep ports uncapped for the minimum time possible.
8. 8

   Install new receiver/drier
   Position the new receiver/drier in the mounting bracket with the same orientation as the original unit, ensuring inlet and outlet ports align with their respective AC lines. Install the mounting fasteners finger-tight initially to allow for alignment adjustment. Torque mounting bolts to specification once line connections are verified for fit.
   Torque spec

   Receiver Drier Bolts10 Nm (7 lb-ft)
9. 9

   Install new O-rings and connect inlet line
   Remove the cap from the inlet line. Inspect the line fitting for damage or debris and clean with lint-free cloth. Install a new O-ring of the correct size onto the line fitting, lubricating lightly with clean PAG oil. Remove the cap from the receiver/drier inlet port and immediately connect the inlet line. For spring-lock couplings, push firmly until an audible click confirms engagement and verify with a pull test. For flare nut fittings, hand-tighten first, then torque to specification.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
10. 10

    Install new O-rings and connect outlet line
    Remove the cap from the outlet line. Inspect the line fitting for damage or debris and clean with lint-free cloth. Install a new O-ring of the correct size onto the line fitting, lubricating lightly with clean PAG oil. Remove the cap from the receiver/drier outlet port and immediately connect the outlet line. Secure the connection using the same method as the inlet line. Torque flare nut fittings to specification if applicable.
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
11. 11

    Reconnect electrical connector
    Reconnect the electrical connector to the pressure switch or sensor on top of the receiver/drier. Ensure the locking tab engages fully with an audible click.
12. 12

    Evacuate AC system
    Connect the vacuum pump to the AC system service ports via manifold gauges. Open both high and low side valves and start the vacuum pump. Evacuate the system to at least 29 inches of mercury (Hg) vacuum. Continue vacuum for a minimum of 45 minutes to ensure all moisture is removed from the system. After evacuation, close the manifold valves and shut off the vacuum pump. Monitor vacuum gauge for 15 minutes; vacuum should hold steady, indicating no leaks. If vacuum drops, locate and repair leaks before proceeding.
13. 13

    Recharge AC system with R-134a
    With the system under vacuum and manifold valves closed, connect the refrigerant supply (tank or recovery cylinder) to the manifold center port. Place the refrigerant container on an electronic scale and note the starting weight. Open the manifold valves to allow refrigerant to flow into the system. For liquid charge, charge through the high side with engine off until system equalizes. Start the engine and set AC to maximum cooling with blower on high. Continue charging through the low side only until the correct refrigerant weight has been added (refer to the underhood label for exact capacity for this specific DB9; do not rely on an estimated figure). Monitor system pressures: low side should stabilize at approximately 25-35 psi, high side at approximately 150-200 psi at idle with 75°F ambient temperature (verify exact target pressures against Aston Martin service data for the DB9). Close manifold valves and disconnect charging equipment. Note: refer to underhood label or Aston Martin service data for the exact refrigerant capacity for this specific DB9 Note: Continue charging through the low side only until the correct refrigerant weight has been added (refer to the underhood A/C specification label for the exact R-134a capacity for this vehicle).
14. 14

    Perform leak test and system verification
    With the system fully charged and running, use an electronic leak detector or UV light (if UV dye was added) to inspect all connection points, particularly the new receiver/drier fittings and O-ring seals. Check the inlet and outlet connections, pressure switch, and nearby fittings. Allow the system to run for 10 minutes and verify cooling performance at the cabin vents (target 40-45°F at full cold). Monitor system pressures to confirm normal operation. If leaks are detected, recover refrigerant, repair connections, and repeat evacuation and recharge procedure.
15. 15

    Reinstall removed components and final checks
    If the air intake duct was repositioned, return it to its original position and secure clamps. Reinstall the engine cover by aligning and pressing down on all quick-release fasteners until seated. Verify all tools and materials are removed from the engine bay. Run the AC system through multiple cycles (off, low, high) and verify pressure switch operation and compressor clutch engagement respond correctly. Check for any unusual noises from the compressor or refrigerant lines.

Reassembly

1. Always use new O-rings at all AC line connections; never reuse old O-rings
2. Minimize the time the AC system is open to atmosphere to prevent moisture contamination (target under 30 minutes from opening to evacuation start)
3. Add the specified amount of fresh PAG oil to the new receiver/drier to compensate for oil trapped in the removed desiccant
4. Ensure all line connections are torqued to specification to prevent leaks while avoiding overtightening that could damage fittings
5. Verify electrical connector to pressure switch is fully seated to prevent false pressure readings or compressor operation issues

Verification

• Start engine and run AC system at maximum cooling for 10 minutes to verify proper operation
• Confirm cabin air temperature reaches 40-45°F with ambient temperature around 75°F
• Verify system pressures stabilize within normal ranges: low side 25-35 psi, high side 200-250 psi at idle (values vary with ambient temperature)
• Check that compressor clutch engages and disengages properly in response to AC controls
• Use leak detector to verify no refrigerant leaks at receiver/drier connections or pressure switch
• Verify pressure switch electrical connector is secure and system responds correctly to pressure changes
• Confirm no unusual noises or vibrations from AC components during operation
• Test AC performance under various engine speeds and ambient conditions to ensure consistent cooling

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