Volkswagen Touran Service Manual: Refrigerant Circuit, General Precautions

Follow the instructions for the workplace. They should be displayed in the workplace.

Ensure absolute cleanliness when working.

Wear work clothing, safety goggles and gloves when working with refrigerant and nitrogen.

Turn on the exhaust gas ventilation system

Use service station to discharge refrigerant circuit, only then open screw connections and replace malfunctioning components. Use caps to seal off opened assemblies and hoses to prevent ingress of moisture and dirt.

Make exclusive use of tools and materials intended for refrigerant R134a.

Be sure to close the container to prevent the refrigerant from absorbing moisture from the air.

Refrigerant Circuit, Flushing with Compressed Air and Nitrogen. Refer to → Chapter "Refrigerant Circuit, Flushing with Compressed Air and Nitrogen".

Flush the refrigerant circuit with R134a refrigerant. Refer to → Chapter "Refrigerant Circuit, Flushing (Cleaning) with Refrigerant R134a"

On vehicles with A/C compressor without magnetic clutch:

Note

The engine should only be started after assembling the refrigerant circuit.

If possible start engine only with a filled refrigerant circuit.

The A/C compressor is always driven by the ribbed belt pulley/torsion elastic clutch. It does not have a magnetic clutch. If an A/C compressor locks-up the overload protection for the A/C compressor shaft is triggered. If no bumps are visible on the ribbed belt pulley/overload protection, the A/C compressor may be blocked. Another indicator is abraded rubber material in the area of the ribbed belt pulley/overload protection. The A/C compressor is equipped with a protected oil supply, this prevents A/C compressor damage in the event that the system is empty. This means that approximately 40 to 50 cm³ of refrigerant oil remains in the A/C compressor. The engine may only be started when the refrigerant circuit is installed correctly. For example; if the refrigerant pipes are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. A/C Compressor Regulator Valve -N280- is not activated when the refrigerant circuit is empty and the A/C compressor idles with the engine.

If it is necessary to start the engine with a discharged refrigerant circuit:

Refrigerant circuit must be fully assembled.

At least a quarter of the prescribed refrigerant oil must be in the A/C compressor.

Do not let the engine RPM go above 2,000.

The engine should run less than 10 minutes.

O-ring

Only O-rings that are resistant to refrigerant R134a and refrigerant oil must be installed. Color coding of O-rings is no longer employed. Colored and black O-rings are used.

Ensure inner diameter on seals used is correct.

Refer to → Rep. Gr.87.

Refer to the Parts Catalog.

O-rings may only be used once.

Before installing, coat the O-rings lightly with refrigerant oil (PAG oil).

Note When flushing components with compressed air and nitrogen, always extract the gas mixture escaping from the components with suitable extraction units (workshop extraction system). After engine all service work, screw sealing caps (with seals) onto all connections with valve and service connections. Before starting up A/C system. Pay attention to the vehicle-specific filling capacities. Refer to → Rep. Gr.87.

Do not fill refrigerant, extract the refrigerant present and refill the system.

After Charging A/C System

After installing a new A/C compressor or fresh refrigerant oil has been filled into compressor (e.g. after blowing through the A/C system), turn ribbed belt pulley of A/C compressor 10 rotations by hand before starting the engine. This prevents damage to the A/C compressor.

For 5-cylinder and 10-cylinder diesel engines, rotate A/C compressor 10 rotations by hand at overload protection. Then install A/C compressor. This prevents damage to the A/C compressor.

Start the engine with the A/C turned off (A/C Clutch -N25- and A/C Compressor Regulator Valve -N280- are not actuated).

Following engine idling speed stabilization, switch on A/C compressor and run it for at least 10 minutes at idling speed with maximum cooling output.

Refrigerant Circuit, General Precautions