Volkswagen Polo Service & Repair Manual: Checking

Volkswagen Polo Service & Repair Manual / Refrrigerant R134a Servicing / Pressures, Checking / Checking with Expansion Valve and Receiver/Dryer, without Regulated A/C Compressor / Checking

–	Turn off the ignition.

–	Connect pressure gauge battery (A/C service station).

–	Take pressure gauge readings. There are two possible results A and B.

Ambient Temperature in °C (°F)	Pressure in Refrigerant Circuit in Bar (psi) Positive Pressure
15 (60)	3.9 (57)
20 (68)	4.7 (68)
30 (86)	6.7 (97)
40 (104)	9.1 (132)

A- The pressure in the refrigerant circuit is lower than the pressure specified in the table. There is not enough refrigerant in the circuit.

- Search for leak with leak detection device.

- The pressure release valve is open, check coolant fan activation according to the wiring diagram.

Check refrigerant pipes and hoses to see if they are bent too sharply (cross-section constrictions) or have external damage. If no malfunction is found, flush refrigerant circuit.

B - The pressure in the refrigerant circuit matches the table or is higher.

–	Start the engine.

–	Set A/C system to maximum cooling output.

–	Open doors.

–	Open vents in instrument panel.

The A/C compressor is driven by the engine via the magnetic clutch using the ribbed belt.

Note

If the A/C compressor is not driven, check A/C Clutch -N25- voltage supply.

If the voltage supply is OK, repair the magnetic clutch.

If the A/C compressor is driven, check refrigerant circuit:

–	Bring engine speed up to 2000 RPM.

–	Observe manometer battery:

Specified Values

High-pressure side:

Increasing from pressure with engine not running to a maximum of 20 bar (290 psi).

Low-pressure side:

Decreasing from pressure with engine not running down to 1.3 bar (18.9 psi).

Test Requirements

Radiator and condenser are clean (clean if necessary). The ribbed belt for the A/C compressor and alternator tensioned correctly. ...

Checking with Restrictor, Reservoir and A/C Compressor Regulator Valve -N280-, Externally Regulated A/C Compressor

Note Connecting service station. Refer to → Chapter „Connecting Service Station“. Observe test requirements ...

Other materials:

A/C Compressor Regulator Valve -N280
Note For switching pressures, removing and installing switches and switch arrangement and version, see vehicle-specific refrigerant circuit. Refer to → Rep. Gr.87. ...

A/C Refrigerant High Pressure Switch -F23
Note For switching pressures, removing and installing switches and switch arrangement and version, see vehicle-specific refrigerant circuit. Refer to → Rep. Gr.87. ...

Tire Wear, Center
This wear pattern is found on drive wheels on high-powered vehicles that often drive long stretches at high speed. At high speeds, the centrifugal force increases the tire diameter at the center of the tread more than at the shoulders of ...