Connect the climate control system to the special repressurizing equipment and check the system pressures by carrying out the test:

See Test 5040OB CHECK ON OPERATION OF AIR CONDITIONING SYSTEM (PRESSURE)

Check the wear condition and correct belt alignment and tensioning.

Run the engine at idle speed with the A/C system off and check whether the noise comes from other auxiliary components (engine fan, water pump, alternator). Increase the rpm and check for vibrations.

Keep the recharging device connected and check the pressure levels in the system high and low pressure circuit with the compressor on and engine running:

• pressure values low in high and low pressure circuit;
• pressure values high in high and low pressure circuit;
• check that the pressure values (high and low) during compressor operation do not pulse and that the circuit does not equalise slowly when the engine is turned off.

1. Flush the system and restore the correct charge of fluid and gas

Op. 0010T84 COOLANT FOR AIR CONDITIONING SYSTEM - DEHYDRATE AND REPRESSURIZE

2. Flush the system and restore the correct charge of fluid and gas

Op. 0010T84 COOLANT FOR AIR CONDITIONING SYSTEM - DEHYDRATE AND REPRESSURIZE

3. Pulsing circuit pressure values (compressor discharge valve permanently open)

Op. 5040A20 AIR CONDITIONING COMPRESSOR - R+R - INCLUDES FLUID LEVEL CHECK AND TOP UP IF NECESSARY

3. Replace the compressor

If the compressor is replaced due to a mechanical problem, remember to clean the entire circuit and change the dehydrating filter.

Check that the compressor and system pipes and components are correctly fastened.

Check the following, in order:

• bracket fastening to the engine block;
• fastening of pipes (by bands and spacers)
• no interference between pipes and other components in the engine compartment
• condenser cleanlineness or damage (presence of mud, foreign bodies).

Also check for cracks in the compressor fastenings to the bracket on the engine block.

3. Clean or replace the condenser

Op. 5040A40 AIR CONDITIONING CONDENSER - R+R

4. Replace the compressor

Op. 5040A20 AIR CONDITIONING COMPRESSOR - R+R - INCLUDES FLUID LEVEL CHECK AND TOP UP IF NECESSARY

Checks to be carried out without the compressor on:

• disconnect the service belt and check for contact between the armature and pulley;
• with the belt disconnected, check for contact between the pulley and external elements;
• Check the wear of the pulley bearing off by rotating the moving plate in both directions of rotation.
• Check whether the compressor magnetic coupling shows signs of overheating.

1. Replace the compressor electromagnetic coupling with pulley

Op. 5040A20 AIR CONDITIONING COMPRESSOR - R+R - INCLUDES FLUID LEVEL CHECK AND TOP UP IF NECESSARY

3. Replace the pulley

Op. 5040A20 AIR CONDITIONING COMPRESSOR - R+R - INCLUDES FLUID LEVEL CHECK AND TOP UP IF NECESSARY

4. Replace the pulley

Op. 5040A20 AIR CONDITIONING COMPRESSOR - R+R - INCLUDES FLUID LEVEL CHECK AND TOP UP IF NECESSARY

If the compressor is replaced due to a mechanical problem, remember to clean the entire circuit and change the dehydrating filter.

After restoring the correct connection of the service belt, turn the compressor on and off to check:

• visually if the compressor magnetic coupling plate slips due to oil or grease on the plate;
• if slippage takes place between the compressor belt and pulley.

With the engine started and the climate control system at the maximum speed (compressor button ON), place the temperature adjustment knob/button in the maximum cold position, move the probe of the leak detector near the connector to be analyzed and check for any leaks.

If there is a leak, repeat the test to make sure that there really is a leak.

Withdraw the pipes from the compressor and ensure that the o-rings on the pipes are correctly positioned.

Check the condition of the pipe fastening threads on the compressor.

With the engine off and the compressor off, bring the leak detector probe up to the compressor pulley near the shaft stem and rear cylinder head gasket to check for leaks. If there is a leak, repeat the test to make sure that there really is a leak. Also check whether the leak is located in other coolant system components.

2. Replace the compressor

Op. 5040A20 AIR CONDITIONING COMPRESSOR - R+R - INCLUDES FLUID LEVEL CHECK AND TOP UP IF NECESSARY

3. Replace the compressor

Op. 5040A20 AIR CONDITIONING COMPRESSOR - R+R - INCLUDES FLUID LEVEL CHECK AND TOP UP IF NECESSARY

4. Remove the leak and restore the circuit to correct operation.

If the compressor is replaced due to a mechanical problem, remember to clean the entire circuit and change the drier filter.