Volkswagen Polo Service & Repair Manual: Checking
| – |
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. |
| – |
Set A/C system to maximum cooling output. |
| – |
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: |
|
|
|
| Increasing from pressure with engine not running to a
maximum of 20 bar (290 psi). |
| Decreasing from pressure with engine not running down to 1.3
bar (18.9 psi). |
|
Radiator and condenser are clean (clean if necessary).
The ribbed belt for the A/C compressor and alternator
tensioned correctly.
...
Note
Connecting service station. Refer to
→ Chapter „Connecting Service Station“.
Observe test requirements ...
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Test Requirements
Checking with Restrictor, Reservoir and A/C Compressor Regulator Valve
-N280-, Externally Regulated A/C Compressor