The compressor is mounted on the engine cylinder block and is driven by a stream belt
The compressor circulates the refrigerant in the system. The compressor shaft is mounted in the aluminum front cover of the housing on bearings and is sealed on the side of the drive pulley by an oil seal
The pulley 2 of the compressor drive is mounted on a double-row ball bearing and rotates constantly when the engine is running.
When the air conditioner is turned on, the torque is transmitted from the pulley to the compressor rotor through a friction clutch with an electromagnetic drive.
If the system is working properly, a click is heard when the air conditioner is turned on – this is the clamping disc 1 of the clutch, under the action of an electromagnet, engages with the pulley 2 of the drive, and the compressor rotor begins to rotate.
But during the operation of the air conditioner, the following compressor malfunctions may occur.
If, when the air conditioner is turned off, the clutch makes extraneous sounds during rotation, warms up or a burning smell appears, then its bearing probably began to collapse
In this case, the bearing must be replaced. In some neglected cases, it may be necessary to replace the compressor coupling assembly or its component parts.
If you do not hear a click after turning on the air conditioner, then the following problems are possible:
- there has been a refrigerant leak, and the control system blocks the compressor from turning on;
– the pressure sensor in the system has failed;
- malfunctions in the electrical circuits of the control system;
- the coil winding of the coupling electromagnet burned out;
- the engine control unit for some reason (high engine coolant temperature, high engine speed) blocked the compressor from turning on.
If the clutch rotates easily and freely, but when the air conditioner is turned on, extraneous noises are clearly heard or even the engine stalls, then most likely the compressor is jammed.
The internal pumping part of the compressor cannot be repaired. In this case, the compressor will have to be replaced.
And the last, most unpleasant option.
A click is heard, the clutch easily rotates the compressor shaft, and there is no cooling of the air in the cabin. In this case, the compressor is idling, pumping nothing.
Only an experienced specialist can determine this malfunction if there is special control and diagnostic equipment.
The most accurate way to determine the cause of the malfunction is after a complete diagnosis in a specialized service center for the repair of automotive air conditioners.
Replacement of the compressor drive pulley bearing
You will need a key for 10, a puller for removing the pulley, a puller for locking rings
We remove the refrigerant from the air conditioning system
Disconnect the negative battery wire
We remove the compressor as described above
Unscrew the fastening bolt, keeping the pressure plate from turning
Removing the bolt
In the photo there is a special device for holding the compressor rotor
We remove the pressure plate from the slots of the compressor shaft
We inspect the working surface of the friction pulley
We do an inspection of the pressure plate so that there are no deep ridges, scuff marks, obvious signs of wear and overheating
We also inspect the slots of the pressure plate
Pay attention to the damper of the pressure plate. On the rubber array of the damper there should be no traces of bulging rubber, cracks, tears
We inspect the surface of the shaft. If there are traces of oil leakage through the shaft seal, the compressor must be replaced
If you replace the oil seal, then, as a rule, this is not for long, since there has probably already been wear on the working surface of the shaft, or wear on the bearing.
We remove the locking ring of the pulley bearing with a puller
Install the puller
And we press the pulley from the landing neck of the front cover of the compressor
It is convenient to use a three-leg puller for pressing the pulley
After removing the pulley, it is necessary to inspect the slots 1 and the threaded hole 2 of the shaft, the grooves 3 for the locking rings and the seating surface 4 of the bearing neck.
If there is wear, then the compressor needs to be replaced
We cut off the rolling fixing of the bearing on the lathe
We press out the old bearing from the pulley with a mandrel of a suitable diameter
We press a new bearing. When pressing, it is necessary to apply force to the outer ring of the bearing
We fix the bearing by the core at the edges of the landing hole
We press the pulley onto the landing neck of the front cover of the compressor.
When pressing, it is necessary to apply force to the inner ring of the bearing
We install the locking ring
We put a pressure plate on the shaft and screw in the fixing bolt
We install the compressor in a vise
We install the arrow indicator, as shown in the figure. We connect the battery plus to the coil winding connector, and the battery minus to the compressor housing.
We measure the gap "A" between the friction surfaces of the pressure plate and the pulley.
If the gap is not the same at different points of the circle, it means that the pressure plate is deformed and needs to be replaced. The nominal clearance is 0.35-0.60 mm.
If the gap is different, re-remove the plate.
With the help of adjusting washers mounted on the rotor shaft, we adjust the gap. Then we put on the pressure plate and check the resulting gap.
Special calibration washers must be used for adjustment
Replacement of the compressor coupling electromagnet
We remove the compressor as described above
We remove the drive pulley
We remove the locking ring of the electromagnet of the compressor coupling with a puller
We use such a release puller to remove the locking ring
Unscrew the mounting screw of the pad holder of the electromagnet coil connector
We shift the electromagnet from the landing belt of the front cover of the compressor and remove it
We check with the tester in the ohmmeter mode the resistance of the coil winding of the electromagnet and the absence of a short circuit to the housing. The coil resistance should be 3.6-3.8 ohms.
Install the electromagnet on the compressor cover and insert the locking ring
When installing the coil on the compressor, the protrusion "A" on the back surface of the coil housing should enter the recess "B" on the compressor cover
After that, we collect all the details in reverse order.
We fill the air conditioning system with refrigerant.