Volvo Coupes/Sedans/Wagons 1970-1989 Repair Guide

Air Conditioning Compressor


See Figure 1

Removing the air conditioning compressor is generally a straightforward task. It may be necessary to remove the compressor for unit repair or for access to other parts of the motor. Removing the compressor from the car requires discharging and recharging the system. It is possible to remove the compressor from its mounts and reposition it out of the way WITHOUT discharging the system or removing the refrigerant hoses.

R-12 refrigerant is a chlorofluorocarbon which, when released into the atmosphere, contributes to the depletion of the ozone layer. Ozone filters out harmful radiation from the sun. Consult the laws in your area before servicing the air conditioning system. In some states it is illegal to perform repairs involving refrigerant unless the work is done by a certified technician. It is also likely that you will not be able to purchase R-12 without proof that you are properly trained and certified to work on A/C systems.

The first three steps of removal are always the same, regardless of type of compressor or system:

  1. Disconnect the negative battery cable.
  3. Discharge the system safely, in accordance with the instructions in General Information & Maintenance .
  5. Remove or reposition any components blocking access to the compressor belt and bolts. Depending on your vehicle, it may be necessary to remove the air intake duct, the power steering pump (Don't disconnect the hoses--just move the pump!) and/or an assortment of vacuum hoses and wires. Where possible, relocate hoses and wires without disconnecting either end. On earlier cars it may be necessary to gently tie the upper radiator hose out of the way; this can be done without draining the coolant system.
  7. Carefully loosen and disconnect the refrigerant lines from the compressor. Immediately cap the lines and compressor ports with tape to prevent entry of dirt and moisture.
  9. Loosen the compressor bolts; move it to loosen the belt and then remove the belt. On the B21, B23 and B230 family of engine, the belt cannot be removed in this fashion. On these engines it is necessary to remove the six bolts holding the crankshaft pulley together. As the pulley comes apart, note the number and placement of the shims between the pulley halves. These shims determine the belt adjustment; it is important that the same number be put back in the same location during reassembly.
  11. Disconnect the wiring to the compressor.
  13. Remove the compressor mounting bolts and remove the compressor. Most compressors are heavier than they appear; support the compressor securely when removing. Keep the compressor in an upright position on the workbench--do not allow oil to run out!
  15. During reassembly, tighten the refrigerant lines to 20 ft. lbs. (27 Nm) and make certain that any small washers or O-rings are in place and properly seated. Remember to remove plugs and tape form lines and ports before installing.
  17. On B21, B23 and B230 engines, the shims within the crank pulley determine belt adjustment. Add or subtract shims as necessary to get the correct belt tension. On all other models, install the belt and draw the correct tension by moving the compressor to the proper position and tightening the mounting bolts.
  19. Attach and secure any components, wires or hoses moved to gain access.
  21. Double check all installation items, paying particular attention to loose hoses or hanging wires, loose nuts, poor routing of hoses and wires (too tight or rubbing) and tools left in the engine area.
  23. Refer to Air Conditioning section in General Information & Maintenance for detailed instructions on recharging the air conditioning system.

Click image to see an enlarged view

Fig. Fig. 1: Add or remove shims to alter A/C compressor belt tension. Cross-sectional view demonstrates the principle-B21, B23 and B230 engines