Test results

Connect the climate control system to the special repressurizing equipment and check the pressure of the system

 See Test 5040OB AIR CONDITIONING SYSTEM OPERATION CHECK (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.

Go to Step 2

1. Pressure levels incorrect

2. Belt alignment/tension incorrect or belt worn.

3. The noise is from other auxiliary components (engine cooling fan, coolant pump, alternator).

1. Go to Step 1

2. Restore correct alignment/tension or replace the belt.

3. Continue as indicated in the diagnostic test procedure.

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;

End of diagnosis

1. Low circuit pressure values (insufficient coolant in circuit)

2. High circuit pressure values (too much coolant, mainly gas, in circuit)

1. Check for leaks in the system and restore the circuit seal if necessary. Then flush the system and restore the correct charge of fluid and gas

 Op. 0010T84 AIR CONDITIONING SYSTEM REFRIGERANT - DEHYDRATING AND REPRESSURIZING

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

 Op. 0010T84 AIR CONDITIONING SYSTEM REFRIGERANT - DEHYDRATING AND REPRESSURIZING

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

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

Check the following, in order:

- compressor fastening to the bracket on the engine block;

- fastening of pipes (by bands and spacers);

- no interference between pipes and other components in the engine compartment;

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

Go to Step 3

1. Fastening of components incorrect

2. Interference in the engine compartment

3. Cracks in the compressor fastenings to the bracket on the engine block.

1. Retighten fastenings to torque

2. Restore the correct layout of the pipes

3. Replace the compressor

 Op. 5040A20 AIR CONDITIONING COMPRESSOR - R.R. INCLUDES CHECKING FLUID LEVEL AND TOPPING UP IF NECESSARY

- 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 by rotating the moving plate in both directions of rotation.

- check whether the compressor magnetic coupling shows signs of overheating.

Go to Step 4

1. Presence of contact between armature and pulley

2. Presence of contact between the pulley and external elements

3. Bearing worn

4. Signs of overheating on the compressor magnetic coupling

1. Replace the compressor electromagnetic coupling with pulley

2. Remove the contact

3. Replace the pulley

4. Replace the pulley

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.

Go to Step 5

1. Oil or grease on the plate

2. Slippage between compressor belt and pulley

1. Clean the oil or grease off the plate and find the oil leak

2. Replace the belt and/or 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 to the connector to be analysed 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

End of diagnosis

1. Compressor pipe o-rings poorly positioned (pinching)

2. Pipe fastening threads not intact

3. Leak located on shaft stem or compressor rear head

4. Leak located in other cooling system components

1. Reposition the compressor pipe o-rings correctly

2. Replace the compressor or restore the thread, where possible

 Op. 5040A20 AIR CONDITIONING COMPRESSOR - R.R. INCLUDES CHECKING FLUID LEVEL AND TOPPING UP IF NECESSARY

3. Replace the compressor

 Op. 5040A20 AIR CONDITIONING COMPRESSOR - R.R. INCLUDES CHECKING FLUID LEVEL AND TOPPING 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.